certificated with a maximum altitude of 25,000 feet or less and at
least 60 minutes for airplanes certificated with a maximum altitude
over 25,000 feet.
    Textron requested the FAA make slight revisions to proposed Sec.
23.1330(a) to harmonize the wording with CS 23.630. Specifically,
Textron recommended requiring the power generation, storage, and
distribution for any system be designed and installed to supply the
power required for operation of connected loads during all intended
operating conditions rather than ``all likely operating conditions''
because it would provide a clear boundary for demonstration of
compliance. In the alternative, Textron suggested removing proposed
paragraph (a) because the requirement is already covered more broadly
in proposed Sec.  23.1300(a)(2).
    The FAA agrees with Textron's recommendation to replace ``likely''
with ``intended'' to harmonize with EASA and make clear the boundary
for demonstration of compliance. Therefore, the FAA did not consider
Textron's alternative recommendation to remove paragraph (a). The FAA
notes that proposed Sec.  23.1330(a) (now Sec.  23.2525) is not
redundant with proposed Sec.  23.1300(a)(2) (now Sec.  23.2500).
Section 23.2500 is a rule of general applicability and does not
supersede more specific rules. It is appropriate for system power
generation, storage, and distribution to be addressed by a specific
rule.
    Air Tractor noted that proposed Sec.  23.1330(b) appears more
restrictive than former Sec.  23.1310 in regards to single-point
failures. The commenter further noted this may require there be no
single failure points between the power supply and the essential load
bus.
    The FAA did not intend for proposed Sec.  23.1330(b) (now Sec.
23.2525(b)) to be more restrictive than the requirements under former
part 23. The FAA revises proposed Sec.  23.1330(b) for clarity by
adding ``of any one power supply, distribution system, or other
utilization system.'' This sets limits as to what needs to be
considered when examining single-point failures.
    Several commenters, including EASA, Kestrel, Daher, and the
Associations raised concerns about the minimum flight times (i.e., 30
minutes and 60 minutes) set forth in proposed Sec.  23.1330(c). The
commenters generally focused on allowing the means of compliance to
define the appropriate minimum flight times and basing the minimum
flight times on airplane performance. Daher suggested that ASTM
standards should provide minimum flight times for battery systems. The
Associations raised concerns the requirement in proposed Sec.
23.1330(c)(1) may be excessive for airplanes with a maximum ceiling
much lower than 25,000 feet. The Associations requested the FAA provide
a reasonable window of essential power required for these lower flying
airplanes for which electrical power will be controlled in a very
reliable but efficient manner due to the nature of their design.
Similarly, BendixKing noted that 25,000 feet and 30 minutes capacity
requirement to supply essential loads may be restrictive to newer
``simple'' airplanes, which operate only at 10,000 feet and require
only 10-15 minutes. Garmin noted the wording of the proposed rule would
require some new electrical-powered airplanes, which may have flight
durations of less than 30 or 60 minutes, to carry the power supply
regardless.
    In response to numerous comments opposing the specific flights
times outlined in proposed Sec.  23.1330(c)(1) and (c)(2) (now Sec.
23.2525(c)), the FAA agrees the language would have been overly
prescriptive and incompatible with new technologies. The FAA revises
proposed Sec.  23.1330(c) to remove the specific time requirements and
add the safety intent requiring enough capacity for the time needed to
complete the functions required for continued safe flight and landing.
    Kestrel questioned whether the language ``design and installation
have enough capacity to supply essential loads'' permitted use of both
the engine start battery and the emergency battery in combination to
supply essential loads in the event of loss of the primary electrical
power generating systems, without the need for an alternate means of
compliance. The commenter noted this is typically addressed using an
ELOS finding to former Sec.  23.1353(h).
    Kestrel also raised concerns about the possible misinterpretation
of the phrase ``if the primary source fails'' in proposed Sec.
23.1330(c). Kestrel said it was aware of at least one such instance,
resulting in the issuance of an STC based on the understanding this
meant failure of the primary generator and proper operation of the
backup alternator. Kestrel asked FAA to revise the wording to prevent
this possible misinterpretation.
    Both of Kestrel's comments relate to a specific design solution and
method of compliance that should be addressed with the use of industry
developed consensus standards or other accepted means of compliance. In
the past, the engine start battery could be used to meet the required
load capacity based on an ELOS finding (as pointed out be Kestrel). The
requirements found in this ELOS finding to former Sec.  23.1353(h)
could be documented in a consensus standard as an acceptable means of
compliance to the regulation. The same applies to the definition of the
``primary source.'' The intent is not to increase

design requirements, but to make showing of compliance more flexible.
    Textron requested the FAA limit the applicability of proposed Sec.
23.1330(c) to electrical systems by changing the title proposed Sec.
23.1330 to ``Electrical system power generation, storage, and
distribution.''
    The FAA disagrees with Textron's proposal as the Part 23 ARC
discussed this issue, with a consensus agreeing the rule should apply
to current technologies such as batteries and new technologies that may
apply in the future. The language proposed by the FAA would implement
the ARC's recommendation, and the FAA makes no changes to that language
in the final rule based on Textron's proposal.
i. External and Cockpit Lighting (Proposed Sec.  23.1335/Now Sec.
23.2530)
    In the NPRM, proposed Sec.  23.1335 (now Sec.  23.2530) would have
required an applicant to design and install all lights to prevent
adverse effects on the performance of flightcrew duties. Proposed Sec.
23.1335 would have required position and anti-collision lights, if
installed, to have the intensities, flash rate, colors, fields of
coverage, and other characteristics to provide sufficient time for
another airplane to avoid a collision. Proposed Sec.  23.1335 would
have required position lights, if installed, to include a red light on
the left side of the airplane, a green light on the right side of the
airplane, spaced laterally as far apart as practicable, and a white
light facing aft, located on an aft portion of the airplane or on the
wing tips. Proposed Sec.  23.1335 would have required that an applicant
to design and install any taxi and landing lights, if required by
operational rules, so they provide sufficient light for night
operations. Finally, for seaplanes or amphibian airplanes, proposed
Sec.  23.1335 would have required riding lights to provide a white
light visible in clear atmospheric conditions.
    Textron commented on proposed Sec.  23.1335(a), explaining it would
have been difficult to design and install lights to ``prevent adverse
effects'' on the performance of flightcrew duties in all cases.
Therefore, Textron recommended the FAA require lights to be installed
to ``minimize,'' rather than ``prevent,'' the possibility they will
adversely affect the satisfactory performance of the flightcrew's
duties.\53\
---------------------------------------------------------------------------

    \53\ This wording was proposed in the ARC final report for Sec.
23.1383.
---------------------------------------------------------------------------

    The FAA agrees the term ``prevent'' would be difficult to comply
with in all cases. The FAA also interprets the term ``prevent'' to be
more restrictive than the former requirements, which used descriptive
terms such as ``no dangerous glare'' in former Sec.  23.1383(a) and
``not seriously affected'' in former Sec.  23.1383(b). The term
``minimize'' more accurately reflects the former requirements of part
23. For these reasons, the FAA revises the proposed rule language to
require the applicant to design and install all lights to minimize any
adverse effects on the performance of flightcrew duties.
    Kestrel commented that the proposed wording, ``as far as space
allows,'' in proposed Sec.  23.1335(c) could be interpreted to mean
that integrated wingtip navigation lights are no longer permitted, and
the only way to meet the requirement is to install external navigation
lights outboard of the wingtips. Kestrel recommended reverting to the
language used in former Sec.  23.1385, which stated that navigation
lights should be ``spaced laterally as far apart as practicable.''
    The FAA agrees with the commenter. The FAA intended proposed Sec.
23.1335(c) (now Sec.  23.2530(c)) to capture the safety intent of
former Sec.  23.1385(c) without an increase in burden for
certification. Former Sec.  23.1385(c) required the left and right
position lights to consist of a red and a green light ``spaced
laterally as far apart as practicable.'' The FAA is reverting back to
this language for the reasons identified by the commenter. Accordingly,
Sec.  23.2530(c) now requires any position lights, if required by part
91, to include a red light on the left side of the airplane and a green
light on the right side of the airplane, spaced laterally as far apart
as practicable.
    Kestrel and Air Tractor commented on proposed Sec.  23.1335(d),
which would have required the installation of taxi and landing lights.
Kestrel asked the FAA to align proposed paragraph (d) with former Sec.
23.1383, which did not require the installation of both taxi and
landing lights, but instead required ``sufficient light for each phase
of night operations.'' Air Tractor suggested the FAA add rule language
to paragraph (d) to make it applicable to taxi and landing lights, ``if
installed,'' because the regulations do not require night operations.
    The FAA did not intend to require the design and installation of
taxi and landing lights in proposed Sec.  23.1335(d) (now Sec.
23.2530(d)). As explained in the NPRM, the FAA intended proposed Sec.
23.1335(d) to capture the safety intent of former Sec.  23.1383, which
required each taxi and landing light to be designed and installed so
that it provided enough light for night operations. The FAA revises the
proposed rule language to more clearly reflect its intent. Accordingly,
Sec.  23.2530(d) now requires any taxi and landing lights to be
designed and installed so they provide sufficient light for night
operations.
    The Associations and ICON recommended the FAA not adopt proposed
Sec.  23.1335(e). The Associations noted that the requirement is
already addressed in regulations concerning maritime vessels, and could
create a conflict should those maritime regulations be changed. The
Associations also noted that there is no safety benefit in duplicate
coverage. ICON commented that the FAA proposed to add a requirement for
a riding light on seaplanes. ICON stated that the operational
requirement for a vehicle to display a white light on the water is not
an FAA requirement and should not be mandated as a vehicle design
requirement by the FAA. ICON recommended the FAA let the agency
controlling the body of water impose this operating rule on seaplanes.
ICON further noted it should not be a design requirement because a
pilot may choose to comply with the requirement by using a portable
light rather than an installed device on an airplane.
    The FAA considered the commenters recommendations but notes
proposed Sec.  23.1335(e) (now Sec.  23.2530(e)) is not a new
requirement. As explained in the NPRM, proposed Sec.  23.1335(e)
captures the safety intent of former Sec.  23.1399. Former Sec.
23.1399 required each riding (anchor) light required for a seaplane or
amphibian, to be installed so it can show a white light for at least
two miles at night under clear atmospheric conditions; and show the
maximum unbroken light practicable when the airplane is moored or
drifting on the water. Former Sec.  23.1399 was adopted on February 1,
1965, as a recodification of CAR 3.704.\54\ The FAA's intent was to
remove the prescriptive requirements of former Sec.  23.1399 to means
of compliance and imposing the safety requirement as a performance-
based standard in paragraph (e). Therefore, the FAA adopts paragraph
(e) as proposed.
---------------------------------------------------------------------------

    \54\ See 29 FR 17955 (1964).
---------------------------------------------------------------------------

    While the commenters did not cite a specific regulation concerning
vessels, the FAA has determined the commenters are referring to Title
33 of the CFR (33 CFR), Navigation and Navigable Waters. 33 CFR part 83
contains rules applicable to all vessels upon the inland waters of the
United States,\55\ and defines a vessel as including every description
of water craft-- including seaplanes--used or

capable of being used as a means of transportation on the water.\56\
Thus, while a seaplane is anchored or afloat upon the inland waters of
the United States, it is subject to part 83. Although Sec.  83.30
contains light requirements for anchored vessels, the FAA finds it
necessary to require seaplanes to have a riding light that provides a
white light visible in clear atmospheric conditions. The objective of
Sec.  83.30 is to ensure vessels see other vessels. The objective of
Sec.  23.2530(e) is to ensure seaplanes are able to see other seaplanes
in the interest of safety, not to provide duplicate coverage. There is
no apparent conflict between part 83 and Sec.  23.2530(e), nor has
there been a known conflict in the last fifty years. Furthermore, Sec.
83.31 states that where it is impractical for a seaplane to exhibit
lights and shapes of the characteristics or in the positions prescribed
in subpart C of part 83, which contains Sec.  83.30, that seaplane
shall exhibit lights and shapes as closely similar in characteristics
and position as possible.
---------------------------------------------------------------------------

    \55\ See 33 CFR 83.01.
    \56\ See 33 CFR 83.03.
---------------------------------------------------------------------------

    Also, former Sec.  23.1399(b) stated that externally-hung lights
may be used. While the FAA removed this prescriptive requirement from
the regulations, it may still be used as an acceptable means of
compliance to Sec.  23.2530(e).
    Finally, Embraer suggested the FAA adopt guidance material and
standards, such as ACs and Agency Process Recommendations, as reference
to the certification project, provided these documents are compatible
with the former part 23 requirements.
    The FAA notes that current published guidance, previously accepted
industry standards, and the prescriptive requirements found in former
part 23 will remain acceptable means of compliance for this final rule.
The FAA will continue to develop guidance as deemed necessary, but
intends to use industry-developed standards if they are found
acceptable. The FAA is actively engaged with industry consensus groups
developing suitable standards for this final rule.
j. Safety Equipment (Proposed Sec.  23.1400/Now Sec.  23.2535)
    In the NPRM, proposed Sec.  23.1400 (now Sec.  23.2535) would have
required safety and survival equipment, required by the operating rules
of this chapter, to be reliable, readily accessible, easily
identifiable, and clearly marked to identify its method of operation.
    Air Tractor noted that the requirement for safety and survival
equipment to be reliable may require some kind of testing or
certification of fire extinguishers. The commenter questioned whether
the current Underwriter's Laboratory (UL) rating of fire extinguishers
would be sufficient.
    The FAA finds the UL rating for fire extinguishers will be an
acceptable means of compliance under Sec.  23.2535, as it was an
acceptable method of compliance under former Sec.  23.1411. As
explained in the NPRM, the FAA intended proposed Sec.  23.1400 (now
Sec.  23.2535) to capture the safety intent of former Sec.  23.1411.
While the FAA removed the prescriptive language from former Sec.
23.1411, it did not intend to change the current method of compliance
for the required safety and survival equipment.
k. Flight In Icing Conditions (Proposed Sec.  23.1405/Now Sec.
23.2540)
    In the NPRM, proposed Sec.  23.1405 (now Sec.  23.2540) would have
required an applicant to demonstrate its ice protection system would
provide for safe operation, if certification for flight in icing
conditions is requested.\57\ Proposed Sec.  23.1405 would have required
these airplanes to be protected from stalling when the autopilot is
operating in a vertical mode. Proposed Sec.  23.1405 would have also
required this demonstration be conducted in atmospheric icing
conditions specified in part 1 of appendix C to part 25 of this
chapter, and any additional icing conditions for which certification is
requested.
---------------------------------------------------------------------------

    \57\ Part 23 Icing ARC recommendations, including
recommendations on activation and operation of ice protection
systems, would have been used as a means of compliance to proposed
Sec.  23.1405(a)(1).
---------------------------------------------------------------------------

    In light of comments received, the FAA revises Sec.  23.2540 to
move proposed paragraphs (a) and (b) to the introductory paragraph, and
renumber proposed paragraphs (a)(1) and (2) as new paragraphs (a) and
(b). This section discusses these changes in more detail.
    The NTSB stated that adopting proposed Sec. Sec.  23.230 (now Sec.
23.2165) and 23.1405 will likely result in Safety Recommendation A-96-
54 being classified ``Closed--Acceptable Action.'' The NTSB agreed with
the FAA's statement in the NPRM that proposed Sec.  23.1405 would
address Safety Recommendations A-07-14 and-15.
    The Associations suggested a better correlation between proposed
Sec. Sec.  23.230 and 23.1405 and added it may be appropriate to
combine these sections.
    In light of this comment, the FAA is restructuring proposed Sec.
23.1405 to be consistent with Sec.  23.2165. Proposed Sec.  23.1405(a)
and Sec.  23.1405(b) were combined into the introductory sentence of
Sec.  23.2540 and modified to read similarly to Sec.  23.2165.
Accordingly, Sec.  23.2540 now requires an applicant who requests
certification for flight in icing conditions defined in part 1 of
appendix C to part 25, or an applicant who requests certification for
flight in these icing conditions and any additional atmospheric icing
conditions, to show compliance with paragraphs (a) and (b) in the icing
conditions for which certification is requested.\58\
---------------------------------------------------------------------------

    \58\ See section III, B. Part 23, Airworthiness Standards,
Subpart B of this preamble (explaining the clarifying change made to
proposed Sec.  23.230(a)).
---------------------------------------------------------------------------

    The FAA is not, however, combining proposed Sec. Sec.  23.230 and
23.1405. The FAA agrees with the Part 23 Icing ARC's and the Part 23
ARC's recommendations to separate the performance and flight
characteristics requirements for flight in icing conditions from the
system requirements for flight in icing conditions.\59\ The FAA notes
Sec.  23.2165 contains the requirement to safely avoid or exit icing
conditions for which certification is not requested, whereas Sec.
23.2540 does not contain such a requirement for systems. The FAA finds
it appropriate to keep these sections separate as the distinction
between the sections means that systems, such as the windshield or air
data, do not have to be evaluated in icing conditions for which the
airplane is not requesting certification.
---------------------------------------------------------------------------

    \59\ See docket number FAA-2015-1621.
---------------------------------------------------------------------------

    Textron and Kestrel commented on ice crystal conditions. Textron
noted that the proposed rule would not have defined ice crystal
conditions and asked the FAA where the term would be defined. Kestrel
asked if the requirements of TSO C16a, ``Electrically Heated Pitot and
Pitot-Static Tubes'', would be an acceptable means of compliance to the
ice crystal requirements of proposed Sec.  23.1405.
    The FAA notes the phrase ``any additional atmospheric icing
conditions'' in proposed Sec.  23.1405 includes ``ice crystal
conditions''. However, the FAA is not defining ``ice crystal
conditions'' in the final rule because it is more appropriately
addressed in means of compliance.
    The FAA finds TSO C16a will be an acceptable means of compliance
when it is revised to include SAE airworthiness standard AS 5562, ``Ice
and Rain Minimum Qualification Standards for Pitot and Pitot-static
Probes''. The FAA notes SAE AS 5562 is an acceptable means of
compliance to the ice crystal requirements for pitot and static
systems. The FAA points out, however, that SAE AS 5562 does not include
ice crystal requirements for certain angle-of-

attack instruments, such as sensors that utilize differential static
pressure.
    Kestrel questioned if the FAA would permit ice protection systems
to be operational on an airplane not certified for Flight Into Known
Ice (FIKI), as it does today via the guidelines established in Appendix
4 of AC 23.1419-2D for ``non-hazard'' systems. Kestrel noted that it
was unclear whether the FAA intends to continue the use of the ``non-
hazard'' classification because the NPRM does not explicitly mention
``non-hazard'' systems. Kestrel believed that operational ice
protection systems on non-FIKI-certified airplane do not need a special
``non-hazard'' classification. Kestrel suggested ice protections
systems could be considered supplemental systems, which are addressed
by the installation and inadvertent operation requirements of proposed
Sec. Sec.  23.1300 and 23.1315.
    Prior to this final rule, the FAA certified ``non-hazard'' systems
in accordance with former Sec. Sec.  23.1301 and 23.1309(a)(2), (b),
(c), and (d). As explained in the NPRM, the FAA intended proposed
Sec. Sec.  23.1300(b) (now Sec.  23.2500(b)), 23.1305 (now Sec.
23.2505), and 23.1315 (now Sec.  23.2510) to capture the safety intent
of the applicable portions of former Sec.  23.1301 and Sec.  23.1309.
Therefore, the FAA intends to certify these ``non-hazard'' systems in
accordance with Sec. Sec.  23.2500(b), 23.2505, and 23.2510.
    The FAA received several comments on proposed Sec.  23.1405(a)(2).
Garmin stated that proposed Sec.  23.1405(a)(2) should apply regardless
of whether an airplane is certified for flight in icing conditions.
Garmin recommended the FAA either move the proposed requirement to
proposed Sec.  23.215 (now Sec.  23.2150) or delete it.
    The FAA agrees that an airplane must be protected from stalling
when the autopilot is operating, regardless of whether the airplane is
certified for flight in icing conditions. However, proposed Sec.
23.1405(a)(2) (now Sec.  23.2540(b)) should not apply to airplanes
where the applicant is not requesting certification for flight in icing
conditions. The stall warning requirements of Sec.  23.2150 will
provide low-airspeed awareness, with or without the autopilot engaged,
for new airplanes not certified for icing. The FAA finds Sec.
23.2165(a) will provide stall warning for new airplanes where the
applicant is requesting certification for flight in icing conditions.
For new airplanes, the FAA acknowledges that a stall warning system
that complies with Sec. Sec.  23.2150 and 23.2165(a) will comply with
Sec.  23.2540(b). Section 23.2540(b) will also be added to the
certification basis of certain STCs and amended TCs on icing certified
airplanes, as discussed below in this section.
    Textron and Rockwell Collins commented on the prescriptiveness of
proposed Sec.  23.1405(a)(2). Textron added that proposed Sec.
23.1405(a)(2), which was in place only for changed product rule
considerations, appeared to be a band-aid solution and not in line with
higher-level goals for the new rules. Textron suggested the FAA delete
proposed paragraph (a)(2).
    The FAA finds that proposed Sec.  23.1405(a)(2), with the exception
of specifying ``vertical mode,'' is performance-based and consistent
with the higher-level goals of the proposal, because the standard does
not specify how to achieve protection from a stall. The FAA expects
means of compliance to include the Icing ARC's recommendations. The FAA
deletes the reference to ``vertical mode'' from Sec.  23.2540(b) to
make it less prescriptive, since it is expected the icing means of
compliance will recognize that only vertical modes may result in
airspeed loss. The FAA renumbers this section as part of the final
rule. Proposed Sec.  23.1405(a)(2) is now Sec.  23.2540(b).
    Additionally, in response to Textron's comment, proposed Sec.
23.1405(a)(2) (now Sec.  23.2540(b)) is intended to increase the safety
of the existing fleet. While Sec.  23.2540(a) and (b) apply to new
airplanes, the FAA intends Sec.  23.2540(b) to specifically target
older airplanes adding an autopilot for the first time, modifying
certain autopilots on airplanes with a negative service history in
icing, or making significant changes that affect performance or flight
characteristics and affect the autopilot. As stated in the NPRM, under
the changed product rule, Sec.  23.2540(b) will be added to the
certification basis of these types of STCs and amended TCs for icing
certified airplanes. This will result in a targeted increase in safety
without requiring compliance to an entire later amendment, including
Sec.  23.2540(a). Compliance with Sec.  23.2540(a) would require the
applicant to address areas unaffected by an autopilot STC. The Part 23
Icing ARC Report (Icing ARC Report) provides examples of modifications
in which new Sec.  23.2540(b) will be applicable. Numerous icing
accidents have shown that unrecognized airspeed loss can occur with
autopilots in altitude hold or vertical speed modes. Means of
compliance other than modifications to the airplanes' stall warning
system may be acceptable under Sec.  23.2540(b) for these STCs and
amended TCs. The Task 9, ``Determine if implementation of NTSB Safety
Recommendation A-10-12 is feasible for part 23 airplanes for operations
in icing conditions,'' discussion in the Icing ARC Report provides
additional background.
    Rockwell Collins stated that proposed Sec.  23.1405(a)(2) could be
interpreted as requiring the autopilot to protect the airplane from
stalling.
    To address the commenter's concern, the FAA revises the proposed
rule language (now Sec.  23.2540(b)) to clarify that the airplane
design must provide protection from stalling when the autopilot is
operating.
    The NTSB disagreed that proposed Sec.  23.1405(a)(2) would address
Safety Recommendation A-10-12, which concerns low-airspeed alerting
systems. The NTSB stated that this safety recommendation would be more
appropriately addressed in proposed Sec.  23.1500, ``Flightcrew
Interface.''
    The FAA notes, as explained in the NPRM, proposed Sec.
23.1405(a)(2) was based on NTSB safety recommendation A-10-12. This
implied proposed Sec.  23.1405(a)(2) responded to recommendation A-10-
12. The FAA acknowledges Sec.  23.2540(b) is not the type of stall
protection the NTSB recommended because it does not require the
installation of low-airspeed alert systems. Instead, Sec.  23.2540(b)
addresses a different and more urgent safety problem by requiring
airplanes with autopilots to provide an adequate stall warning in icing
conditions. Furthermore, Sec.  23.2540(b) is an airworthiness standard
that establishes a minimum level of safety for all airplanes under part
23. If the FAA were to adopt a requirement in part 23 that required
applicants to install a low-speed alert system in their airplanes, that
requirement would apply to all airplanes. The FAA did not propose such
a requirement because safety recommendation A-10-12 applies only to
commercial airplanes under part 91 subpart K, and parts 121, and 135.
To properly respond to NTSB safety recommendation A-10-12, the FAA
would have to change the operating rules, which is outside the scope of
this rulemaking.
    Embraer and Garmin both commented on the term ``demonstration.''
Embraer recommended the FAA change ``in atmospheric icing conditions''
in proposed paragraph (b) to ``considering atmospheric icing
conditions''. Embraer stated that its proposal aimed to make a broad
statement, implying that there may be several means of addressing the
icing conditions as shown in figures 1 through 6 of Appendix C to Part
25. The commenter asserted the original text in the NPRM might be
understood as

requiring only a flight test demonstration. Garmin commented on the
importance of clarifying this term because the FAA Aircraft
Certification Office has almost always insisted that ``demonstration''
means the applicant must perform it on an airplane.
    In light of these comments, the FAA is using the phrase ``must
show'' rather than ``must demonstrate'' in the introductory sentence of
Sec.  23.2540, which is consistent with the changes made to Sec.
23.2165. This change is also consistent with the NPRM, which explained
that demonstration, as a means of compliance, may include design and/or
analysis and does not mean flight tests are required. However, for the
foreseeable future, the FAA does expect means of compliance to include
icing flight tests for applicants seeking icing certification for new
TCs.
l. Pressurized System Elements (Proposed Sec.  23.1410/Now Sec.
23.2545)
    In the NPRM, proposed Sec.  23.1410(a), (c) and (d) (now Sec.
23.2545) would have required the minimum burst pressure of--
     Hydraulic systems be at least 2.5 times the design
operating pressure with the proof pressure at least 1.5 times the
maximum operating pressure;
     Pressurization system elements be at least 2.0 times, and
proof pressure be at least 1.5 times, the maximum normal operating
pressure; and
     Pneumatic system elements be at least 3.0 times, and proof
pressure be at least 1.5 times, the maximum normal operating pressure.

Proposed Sec.  23.1410(e) would have required that other pressurized
system elements to have pressure margins that take into account system
design and operating conditions. Additionally, proposed Sec.
23.1410(b) would have required engine driven accessories essential to
safe operation to be distributed among multiple engines, on multiengine
airplanes.
    In light of comments received, the FAA withdraws proposed Sec.
23.1410(a) through (e) and adopts new language for Sec.  23.2545. This
section discusses these changes in more detail.
    Garmin commented that proposed Sec.  23.1410 was still extremely
prescriptive and suggested the FAA revise the rule to a higher safety
objective, and burst and proof pressures should be in a consensus
standard. Garmin proposed alternative, less prescriptive language. ANAC
similarly stated that parts of proposed Sec.  23.1410 were too
prescriptive and suggested that it might be more appropriate to set the
``minimum burst'' and ``proof pressure'' values for the hydraulic,
pressurization, and pneumatic systems using consensus standards. ANAC
also proposed alternative language.
    The FAA agrees with ANAC's recommendation to set the proof and
burst factors for hydraulic, pneumatic and pressurization systems in
consensus standards or means of compliance. This is consistent with the
FAA's goal of moving from prescriptive regulations to performance-based
regulations. The FAA did not use Garmin's suggested language because it
did not clearly state that the requirement was for ``proof'' and
``burst'' pressure, and would have applied to ``pressurized system
elements''. This may be more limited than using the phrase
``pressurized system''. ANAC's suggested language was also not used
because it was not inclusive of all pressurized systems. Consensus
standards or means of compliance can be used to document the
appropriate proof and burst factors, the operating pressure to be
factored, pass/fail criteria for tests, and other information included
in former Sec.  23.1435(a)(4), (b), Sec.  23.1438, and AC 23-17C.
    Textron noted it is unclear what the difference is between the
terminology used to describe the system pressures upon which the
factors in proposed Sec.  23.1410(a), (c), (d), and (e) are applied
(i.e., ``design operation pressure,'' ``maximum operating pressure,''
and ``maximum normal operating pressure.''). ANAC made a similar
observation, as it noted the phrase ``maximum operating pressure'' in
proposed Sec.  23.1410(a) and the phrase ``maximum normal operating
pressure'' in proposed Sec.  23.1410(b) and (c) might share the same
interpretation. ANAC recommended a harmonization between these
paragraphs in order to avoid misinterpretations for the consensus
standards, while Textron suggested that using the ASTM to identify
those differences would be more in keeping with the move from
prescriptive to performance-based standards. ANAC also recommended
merging proposed Sec.  23.1410(a), (c), and (d).
    The FAA agrees with merging proposed Sec.  23.1410 (a), (c) and (d)
because they are similar and related. In addition, the FAA has decided
to merge proposed Sec.  23.1410(e) with these requirements to address
all systems containing fluids under pressure. Therefore, the FAA
withdraws proposed paragraphs (a), (c), (d), and (e) and adopts new
language in Sec.  23.2545 that requires pressurized systems to
withstand appropriate proof and burst pressures.
    ANAC, Textron, and an individual commenter addressed proposed Sec.
23.1410(b). ANAC recommended the provision be deleted. In addition to
being prescriptive, ANAC noted the provision is already addressed in
proposed Sec.  23.1315, which evaluates in a more systematic way the
design and installation of a system or component according to their
failure condition that is directly related to the airplane safe
operation. Additionally, Textron said the provision is misplaced and
should be moved to proposed subpart E, Sec.  23.900 or Sec.  23.910
(now Sec.  23.2410). An individual commenter also recommended moving
the provision to Sec.  23.900.
    Based on the comments, the FAA has decided that the safety intent
of this requirement is adequately addressed in Sec.  23.2510 and Sec.
23.2410. Section 23.2510 requires equipment separation and redundancy
based on the severity of equipment failures. Section 23.2410 requires
powerplant failures, including engine driven accessory failures, to be
considered and mitigated--effectively requiring safety critical engine
driven accessories to be distributed on multiengine airplanes.
Therefore, the FAA withdraws proposed Sec.  23.1410(b) from the final
rule; hence, there is no reason to place it elsewhere.
m. Equipment Containing High-Energy Rotors (Sec.  23.2550)
    The requirements of former Sec.  23.1461 were not fully
incorporated into proposed Sec.  23.755(a)(3), so the FAA creates a new
Sec.  23.2550 to correct this omission. The preamble section for Sec.
23.2320 discusses this change in more detail.
8. Subpart G--Flightcrew Interface and Other Information
a. General Discussion
    In the NPRM, the FAA proposed substantial changes to former subpart
G based on its assessment that many of the regulations contained in
this subpart contain prescriptive requirements that are more
appropriate for inclusion as means of compliance to the new part 23
performance-based regulations. The FAA noted this approach would
provide at least the same level of safety as current prescriptive
requirements while providing greater flexibility for future designs.
The FAA also expanded the scope of the subpart to address flightcrew
interface requirements.
    Zee agreed with the FAA's proposal to expand subpart G to address
not only current operating limitations and information, but also
flightcrew interface. Zee noted that, based on current technology, the
FAA anticipates new airplanes will heavily rely on

automation and systems that require new and novel pilot or flightcrew
interface methods and procedures. The commenter noted further that more
automated systems could dramatically reduce cockpit workload, which
would be a great boon for the public who has shied away from personal
aviation transportation due to increasing operational complexities of
traditional airplanes.
    EASA commented that information from various other subparts in
proposed part 23 should be included in subpart G to provide
requirements on how the information should be provided. EASA noted that
proposed subpart G could include requirements for subjects such as
flightcrew interface; function and installation, flight, navigation,
powerplant instruments, cockpit controls, instrument markings, control
markings and placards, airplane flight manual, and instructions for
continued airworthiness. EASA also noted these subjects were under
consideration by EASA for inclusion as separate sections in a future
proposal to revise CS 23.
    The FAA finds its proposed actions respond to the concerns of Zee,
EASA, and others within the industry to better address the issue of
flightcrew interface. The FAA recognizes that flightcrew interface
issues have become increasingly more important as a result of recent
technological developments in flight, navigation, surveillance, and
powerplant control systems. The FAA partially agrees with EASA's
comment that information from various other subparts in proposed part
23 should be included in subpart G. However, the FAA finds the full
extent of the material EASA proposes for inclusion would establish
requirements that would be too prescriptive in nature and therefore not
in accord with the overall objective of this rulemaking to replace the
detailed prescriptive requirements with more general performance-based
standards. The FAA does, however, acknowledge that certain sections of
EASA A-NPA 2015-06 and NPA 2016-05 may better address those
requirements where the FAA's proposed language may have been too
general in nature and not sufficiently detailed to permit adequate
means of compliance to be developed. In a number of instances, the FAA
has adopted either the specific regulatory language used by EASA or
similar equivalent language to better address those safety concerns and
achieve greater harmonization. The specific instances where the FAA has
adopted these revisions are discussed in the preamble to the sections
in which those changes have been made.
    The FAA notes that EASA proposed the inclusion of three sections in
its revision of CS 23, subpart G, which added substantial detail to
that subpart. The FAA did not include corresponding sections within its
proposed subpart G. Proposed CS 23.2605, ``Installation and operation
information'', and proposed CS 23.2610, ``Flight, navigation, and
powerplant instruments'', however, did correspond to proposed Sec.
23.1305 and proposed Sec.  23.1310, respectively, in subpart F of the
NPRM. Proposed CS 23.2615, ``Cockpit controls,'' was also in EASA's
proposed subpart G, but did not have a corresponding section in the
NPRM.
    The FAA agrees that placing the requirements contained in these
sections into subpart G is more appropriate than addressing those
requirements in subpart F, as these requirements more directly relate
to flightcrew interface issues. Accordingly, the FAA is relocating
proposed Sec.  23.1305 to subpart G, Sec.  23.2605, ``Installation and
operation,'' and proposed Sec.  23.1310 to Sec.  23.2615, ``Flight,
navigation, and powerplant instruments.'' While adopting the general
safety intent embodied in EASA's proposed regulations, the FAA is not
including the complete level of detail specified in those regulations
because the FAA considers the additional information more appropriate
as a means of compliance. While the FAA believes that cockpit controls
should be addressed under subpart G, the FAA did not include a separate
section in the final rule equivalent to proposed CS 23.2615 because the
FAA has determined these requirements are more appropriate as a means
of compliance to Sec.  23.2600.
b. Flightcrew Interface (Proposed Sec.  23.1500/Now Sec.  23.2600)
    In the NPRM, proposed Sec.  23.1500 (now Sec.  23.2600) would have
required the pilot compartment and its equipment to allow each pilot to
perform their duties, including taxi, takeoff, climb, cruise, descent
approach and landing. The pilot compartment and its equipment would
also have to allow a pilot to perform any maneuvers within the
operating envelope of the airplane, without excessive concentration,
skill, alertness, or fatigue. Proposed Sec.  23.1500 would have
required an applicant to install flight, navigation, surveillance, and
powerplant controls and displays so qualified flightcrew could monitor
and perform all tasks associated with the intended functions of systems
and equipment so as to make the possibility that a flightcrew error
could result in a catastrophic event highly unlikely.
    Textron noted that proposed Sec.  23.1500 has ``minimal wording''
as compared to CS 23.460 and recommended the FAA harmonize proposed
Sec.  23.1500 with EASA's proposed provisions.
    Textron also specifically recommended the FAA add the requirement
in former Sec.  23.671(b) for controls to be arranged and identified to
provide convenience in operation and to prevent the possibility of
confusion and subsequent inadvertent operation, to proposed Sec.
23.1500.
    The FAA has reviewed EASA A-NPA 2014-12 and NPA 2016-05 and finds
the level of detail included in the crew interface requirements in both
documents may be overly restrictive. The FAA finds Sec.  23.2600
adequately address pilot compartment requirements and the requirements
for the provision of necessary information and indications to the
flightcrew. The FAA is not revising Sec.  23.2600 as EASA recommended,
because the FAA is concerned that adding the extensive level of detail
that EASA is considering for inclusion in subpart G would neither
enhance the FAA's ability to respond to the introduction of new
technology nor foster future innovation. The FAA notes the adoption of
the EASA's recommended requirements would only serve to create issues
similar to those that the FAA is attempting to address with this
significant revision of part 23 airworthiness standards. However, the
FAA recognizes Textron's concerns and agrees that cockpit controls
should not only be convenient to operate, but also prevent the
possibility of confusion and subsequent inadvertent operation.
Nevertheless, the FAA finds the regulatory intent of former Sec.
23.671 will be achieved because Textron's concerns will be addressed in
any means of compliance developed and submitted for acceptance to
demonstrate compliance with Sec.  23.2600.
    Air Tractor raised concerns that proposed Sec.  23.1500(b) added a
requirement that the flightcrew be able to monitor and perform ``all''
tasks associated with the intended functions of systems and equipment.
Air Tractor recommended the FAA insert the term ``required'' after
``all'' to ensure the proposal would not require the performance and
monitoring of non-required tasks. An individual commenter at the FAA's
public meeting also shared concerns regarding use of the term ``all''
and asked if its use would preclude systems from monitoring tasks the
flightcrew does not have to continuously monitor.
    The FAA agrees that use of the term ``all'' is too encompassing in
this section

and could be misinterpreted to impose requirements that would exceed
the safety intent of the rule. However, the FAA finds adding the term
``required'' would make the rule's requirements narrower than the FAA
intended. The FAA notes that airplanes are currently equipped with
systems and equipment that are not necessarily required, yet the
flightcrew must be able have the ability to monitor and perform all
tasks associated with the intended functions of those systems and
equipment to operate the airplane safely. Accordingly, the FAA has
determined that including the term ``defined'' in Sec.  23.2600(b) will
address both the concerns of Air Tractor and the FAA, and also allow
for the installation of systems and equipment that can be used to
monitor a function or parameter for the flightcrew. The FAA notes this
term is currently used in Sec.  25.1302(a), which addresses flightcrew
interface with systems and equipment installed in transport category
airplanes. While the FAA recognizes that many of the requirements in
Sec.  25.1302 are inappropriate for the certification of airplanes
under part 23, the FAA finds its use of the concept of ``defined
tasks'' is appropriate for application to part 23 flightcrew interface
requirements.
    An individual commenter asserted that proposed Sec.  23.1500(b) is
``convoluted and subject to varying interpretations.'' The commenter
noted that one such interpretation could be the flightcrew would not be
required to monitor and perform tasks and prevent errors that go beyond
the intended functions of the installed systems and equipment.
Accordingly, the commenter asserted that if there is no equipment
installed to prevent CFIT, such as TAWS, there would be no requirement
for monitoring and performing tasks and preventing errors associated
with terrain clearance. The commenter also stated the rule could be
interpreted to mean the tasks, monitoring, and error prevention
requirements are those associated with a particular flight phase and
flight conditions. For example, the commenter noted that there must be
equipment to prevent CFIT (e.g., TAWS or other), at least for IFR-
certified airplanes, and it must meet the stated requirements. The
commenter noted that many situations and types of equipment could be
affected by the proposal and maintained that if these interpretations
were accurate, there would be obvious cost, weight, practicability, and
other implications that were not adequately addressed in the preamble
or Regulatory Analysis.
    In the NPRM, the FAA stated that it proposed to expand subpart G to
address not only current operating limitations and information, but
also the concept of flightcrew interface. The FAA further noted that it
was proposing to address the pilot interface issues found in subparts D
and F in proposed Sec.  23.1500. Otherwise, subpart G retained the
safety intent of the requirements in the former rules. This section
does not impose additional equipment requirements, as suggested by the
commenter's example, but it does require consideration of the
flightcrew interface and human factors in the design and installation
of equipment. The FAA notes the commenter's concern that the flightcrew
would not be required to monitor and perform tasks, such as terrain
avoidance, that are not directly addressed by installed systems and
equipment.
    Several commenters raised concerns regarding the use of the term
``highly unlikely'' in proposed Sec.  23.1500(b) that addresses the
ability of the system and equipment design to avoid the possibility
that a flightcrew error could result in a catastrophic event. One
individual commenter specifically noted that ``highly unlikely'' is a
new and undefined term. The commenter recognized that prevention of
errors undoubtedly would increase safety, but noted there is a limit to
how much system and equipment design error prevention is justified and
practicable in any airplane, not just those certificated under the
provisions of part 23. This commenter also contended it would be
difficult to comply with a stringent reading of ``highly unlikely'' and
asserted a review of accident history would reveal this. Garmin, Air
Tractor, and BendixKing submitted similar comments regarding the
potential for this proposed requirement to increase the burden on
applicants. Each of these commenters proposed alternative regulatory
language addressing their concerns.
    The Associations commented that the intent of this proposed
requirement is to prevent likely flightcrew errors with flight,
navigation, surveillance, and powerplant controls and displays and
proposed language to meet this intent. Textron also noted the proposed
requirement failed to exclude skill related errors, errors as a result
of malicious intent, recklessness, and actions taken under duress.
Textron contended that system designs should not be responsible for all
possible flightcrew errors, but only for reasonable errors. Textron
recommended proposed alternative regulatory language addressing its
concern.
    Astronautics said the term ``highly unlikely,'' as it relates to
``catastrophic,'' would cause confusion in the context of failure
condition categorization and likelihood of occurrence. The commenter
suggested replacing the term ``highly unlikely'' with recognized terms
that categorize failure hazards and probabilities. Astronautics also
suggested recognizing a flightcrew error may have differing degrees of
severity by revising the proposed rule to include consideration of the
three different degrees of failure in proposed Sec.  23.1315(b).
    The FAA agrees with many of the commenters concerns regarding the
use of the term ``highly unlikely'' in addressing the probability of
preventing flightcrew errors resulting from system and equipment
designs that could lead to catastrophic events. The FAA also recognizes
the difficulty in assessing complex flightcrew interface issues
associated with the approval of control and display designs. Prior to
the adoption of this rule, the FAA utilized very prescriptive
requirements with associated guidance material based on its need to
address traditional controls, displays, and flight operations in the
certification process. Although the FAA expects that this prescriptive
language for the evaluation of traditional controls and displays will
serve as a means of compliance with the new performance-based
requirements, the FAA determines the new performance-based requirements
will also allow for alternative approaches to meeting flightcrew
interface requirements for non-traditional airplanes, operations, and
non-traditional controls and displays.
    As the FAA noted in the NPRM preamble, the smart use of automation
and phase-of-flight-based displays could reduce pilot workload and
increase pilot awareness. Accordingly, the FAA finds new technology can
help the pilot in numerous ways, all with the effect of reducing pilot
workload, which should help reduce accidents based on pilot error. The
FAA intended to remove many of the barriers to the introduction of new
technology while still retaining a clear performance-based requirement
to which an applicant could demonstrate compliance. The FAA recognizes
the potential for misinterpretation of the requirements with this new
approach; however, the FAA's intent is not to increase the requirements
set forth in former regulations, unless specifically stated in the
preamble. The FAA expects the use of performance-based requirements to
address flightcrew interface issues will result in the accelerated
development of industry standards that will be used to improve the
manner in which pilots

interface not only with information that has been traditionally
provided to them but also with new information. Section 23.2600 is not
intended to add any burden on the applicant and is expected to reduce
time to market for new system and equipment designs, thereby, resulting
in reduced costs.
    As several commenters noted, the terms ``highly unlikely'' and
``catastrophic'' have specific meanings with respect to the
certification of systems that typically are not used when addressing
human interactions. Based on the commenters' recommendations, the FAA
finds the best approach to adequately address flightcrew interface
issues is to revise Sec.  23.2600 using language similar to that
contained in former Sec.  23.1309(d), which states that systems and
controls must be designed to minimize crew errors which could create
additional hazards. This avoids the problems associated with the use of
language more appropriate for evaluation of system and equipment
failures.
    Shortly after the close of the comment period, EASA published NPA
2016-05, which proposed requirements to address an oversight in the
NPRM regarding the pilot visibility requirements originally contained
in subpart D. The FAA has adopted EASA's proposed language both in
paragraphs (a) and (c) to correct this oversight in the FAA's proposal,
to ensure that pilot compartment visibility requirements are addressed.
Adopting these requirements serves to ensure that pilot view
requirements, and particularly those requirements that could result
from the loss of vision through a windshield panel in a level 4
airplane, are addressed. The FAA finds that these revisions impose no
requirements in excess of those specified in the former Sec.  23.775
and will maintain the level of safety set forth in part 23, through
amendment 23-62, as originally intended in the proposal. As discussed
in the context of proposed Sec.  23.755, the requirement for level 4
airplanes that the flightcrew interface design must allow for continued
safe flight and landing after the loss of vision through any one of the
windshield panels has been moved to Sec.  23.2600(c).
c. Installation and Operation (Proposed Sec.  23.1305/Now Sec.
23.2605)
    In the NPRM, proposed Sec.  23.1305 (now Sec.  23.2605) would have
required each item of installed equipment--
     To perform its intended function;
     Be installed according to limitations specified for that
equipment; and
     The equipment be labeled, if applicable, due to the size,
location, or lack of clarity as to its intended function, as to its
identification, function, or operation limitations, or any combination
of these factors.

Proposed Sec.  23.1305 would have required a discernable means of
providing system operating parameters required to operate the airplane,
including warnings, cautions, and normal indications to the responsible
crewmember. Proposed Sec.  23.1305 would have also required information
concerning an unsafe operating condition be provided in a clear and
timely manner to the crewmember responsible for taking corrective
action.
    In light of comments received, the FAA revises proposed Sec.
23.1305 by moving paragraphs (a)(2) through (c) to new Sec.  23.2605.
This section discusses these changes in more detail.
    The function and installation rule language in proposed Sec.
23.1305 was originally located in subpart F, Equipment. The logic
behind the location of these requirements was that requirements for the
display and control of a specific function would be in subpart G, while
requirements for the hardware or software for the display or control
are would be in subpart F. For this reason, proposed Sec.  23.1305,
``Function and installation,'' included specific paragraphs from the
requirements of former Sec. Sec.  23.1301, 23.1303, 23.1305, 23.1309,
23.1322, 23.1323, 23.1326, 23.1327, 23.1329, 23.1331, 23.1335, 23.1337,
23.1351, 23.1353, 23.1357, 23.1361, 23.1365, 23.1367, and 23.1416.
    The Associations recommended the FAA delete proposed Sec.
23.1305(a)(2) and (a)(3). The commenters also suggested the FAA delete
proposed Sec.  23.1305(b), as the flightcrew interface portion of the
proposed rules already addressed the same subject area. Furthermore,
EASA recommended moving the flightcrew interface requirements from
proposed Sec.  23.1305(a)(2) through (c) to subpart G.
    The FAA agrees with the commenters that the paragraphs in proposed
Sec.  23.1305 that address display and control for the flightcrew is
better located in subpart G. Upon closer review, the FAA agrees with
EASA's recommendation as it is consistent with the FAA's intent behind
moving requirements from subpart F to subpart G. As proposed, subpart G
did not have any sections that directly address these specific
paragraphs. For that reason, the FAA adds new Sec.  23.2605,
``Installation and operation'', which contains the language from
proposed Sec.  23.1305(a)(2) through (c).
d. Instrument Markings, Control Markings, and Placards (Proposed Sec.
23.1505/Now Sec.  23.2610)
    In the NPRM, proposed Sec.  23.1505 (new Sec.  23.2610) would have
required each airplane to display in a conspicuous manner any placard
and instrument marking necessary for operation. Proposed Sec.  23.2610
would also have required an applicant to clearly mark each cockpit
control, other than primary flight controls, as to its function and
method of operation and include instrument marking and placard
information in the AFM.
    Astronautics agreed that an applicant should ensure markings are
adequate and meet the marking requirements specified in 14 CFR 45.11,
``Marking of products.'' However, they asserted that the requirement
for applicants to mark the controls and instruments themselves, as
required by proposed Sec.  23.1505(b), is ``overly broad.'' The
proposed requirement fails to account for existing markings such as
those required by Sec.  45.15, ``Marking requirements for PMA articles,
TSO articles, and critical parts.'' Astronautics noted that some
controls, such as knobs and push buttons, are typically integrated
parts of TSO articles. The commenter believed that proposed Sec.
23.1505 could be interpreted to require an applicant to add or replace
markings on instruments already marked pursuant to a TSO authorization
or PMA. Astronautics recommended the FAA revise proposed Sec.  23.1505
to specify that an applicant is not required to alter markings already
required under Sec.  45.15.
    The FAA agrees with Astronautics that the proposal is overly
prescriptive as to how information regarding function and method of
operation is to be provided. Accordingly, the FAA removes the
requirement from proposed paragraph (b) specifically requiring an
applicant to mark cockpit controls and instruments and revises the
proposal to require the airplane design clearly indicate the function
of each cockpit control (other than primary flight controls). This
revision will permit an applicant to utilize markings made pursuant to
a TSO authorization or PMA without imposing a repetitive and
potentially conflicting requirement.
    BendixKing requested the FAA delete the phrase ``. . . and method
of operation'' from proposed Sec.  23.1505(b). The commenter believed
that the marking of cockpit controls should be limited to labeling the
function of the control and that including its method of operation as a
marking requirement is neither bounded nor appropriate.

    The FAA agrees in part with BendixKing's comment. The FAA concurs
that application of the proposed requirement to all cockpit controls
(other than primary flight controls) is overbroad and could lead to an
applicant including information on cockpit control markings that is
excessive, unnecessary, and contrary to the agency's original intent.
Accordingly, the FAA revises proposed paragraph (b) to eliminate the
proposed requirement that an applicant mark cockpit controls with their
method of operation. However, cockpit controls (other than primary
flight controls) would continue to be required to clearly indicate
their function. As under the former regulations, information on the
method of operation of equipment is provided in the airplane flight
manual and equipment manuals, which is sufficient to satisfy the
objective of the proposal.
    Textron requested the FAA be more specific as to what placards
(i.e., emergency, passenger safety, or operational placards) need to be
included in the AFM pursuant to proposed Sec.  23.1505(c).
    The FAA recognizes that information may be provided to pilots and
passengers using a variety of methods and considers it unnecessary to
specifically prescribe those placards that must be included in the AFM.
Additionally, a requirement to include specific placards would be
counter to this rule's intent to remove prescriptive requirements from
current regulatory text and replace those provisions with performance-
based regulations. The FAA finds that variations in airplane designs
and the methods of providing information to pilots and passengers may
necessitate the need for various types of placard information that
would be more appropriate for inclusion as a means of compliance to the
regulatory requirements, thereby providing applicants with more
flexibility in meeting the underlying safety intent of the rule.
e. Flight, Navigation, and Powerplant Instruments (Proposed Sec.
23.1310/Now Sec.  23.2615)
    In the NPRM, proposed Sec.  23.1310 (now Sec.  23.2615) would have
required installed systems to provide the flightcrew member who sets or
monitors flight parameters for the flight, navigation, and powerplant
information necessary to do so during each phase of flight. Proposed
Sec.  [thinsp]23.1310 would have required this information include
parameters and trends, as needed for normal, abnormal, and emergency
operation, and limitations, unless an applicant showed the limitation
would not be exceeded in all intended operations. Proposed Sec.
[thinsp]23.1310 would have prohibited indication systems that integrate
the display of flight or powerplant parameters to operate the airplane
or are required by the operating rules of this chapter, from inhibiting
the primary display of flight or powerplant parameters needed by any
flightcrew member in any normal mode of operation. Proposed Sec.
[thinsp]23.1310 would have required these indication systems be
designed and installed so information essential for continued safe
flight and landing would be available to the flightcrew in a timely
manner after any single failure or probable combination of failures.
    Several commenters raised concerns with proposed Sec.
23.1310(a)(1), which would have required installed systems to provide
the flightcrew member with parameters and trends, as needed. Air
Tractor questioned whether round gauge instruments produce a trend and
whether the FAA would use paragraph (a)(1) to mandate electric gauges.
Similarly, Garmin contended that proposed Sec.  23.1310(a)(1) could be
interpreted as requiring more information than was formerly required.
Garmin noted the pilot often determines the trend by monitoring a
gauge, but the trend itself may not be displayed. Garmin asked the FAA
to clarify whether it intended paragraph (a)(1) to require trend
information to be displayed, or information to be presented in a manner
that enables the pilot to monitor the parameter and determine trends.
Genesys Aerosystems commented that requiring ``trends'' rather than
addressing ``trends'' in guidance materials would lead to more trends
being required than needed.
    The FAA did not intend proposed Sec.  23.1310(a)(1) to require
electric gauges. Traditional analog indicators, such as airspeed
indicators or altimeters, have been shown to provide adequate trend
indications and will still be acceptable. It may also be possible to
have a system that automatically monitors the parameter of interest and
warns the pilot of any trend that could lead to a failure. Paragraph
(a)(1), however, does not allow a light that comes on at the same time
that the failure occurs to replace analog indicators because such a
light does not provide trend information prior to a failure. A warning
light system that would comply must be sophisticated enough to read
transients and trends, and give a useful warning to the pilot of a
potential condition.
    The FAA agrees the proposed rule language could have been
misinterpreted as requiring more information than former part 23. The
FAA intended proposed Sec.  23.1310 to capture the safety intent of the
former requirements, which was to provide flightcrew members the
ability to obtain the information necessary to operate the airplane
safely in flight, but not to exceed the safety intent of former part
23. Therefore, proposed Sec.  23.1310(a)(1) was intended to require
installed systems to provide adequate information to the flightcrew
member to determine trends by monitoring a gauge or display. The FAA
did not intend to expressly require an installed system to display the
trend itself, because not all systems display trends. The FAA revises
the proposed rule language to clarify its intent. Accordingly, Sec.
23.2615(a)(1) now requires the information to be presented in a manner
that enables the flightcrew member to monitor parameters and determine
trends, as needed, to operate the airplane.
    Former Sec.  23.1311(a)(6) required electronic display indicators
to incorporate, as appropriate, trend information to the parameter
being displayed to the pilot. Section 23.2615(a)(1) is not meant to be
an increase in burden from the former requirement and associated
guidance regarding when trends are needed.
    Kestrel raised concerns that although proposed Sec.  23.1310 is
less prescriptive, it did not minimally require the pilot to have
available airspeed, altitude, direction, and attitude indicators as
former Sec.  23.1303 prescribed. The commenter asked if the FAA
envisions a scenario where this information would not be required.
Kestrel was also concerned that the phrase ``as needed'' would lead to
diverging FAA interpretations of proposed Sec.  23.1310(a)(1). The
commenter asked the FAA to clarify its intent regarding the requirement
to provide parameters and trends ``as needed.'' If this was not a fixed
set of parameters, Kestrel asked for details on how this list would be
determined.
    As explained in the NPRM, the former regulations that required
airspeed, altimeter, and magnetic direction were redundant with the
operating rules, specifically Sec. Sec.  91.205 and 135.149.
Furthermore, they required prescriptive design solutions that were
assumed to achieve an acceptable level of safety. These prescriptive
solutions precluded finding more effective or more economical paths to
providing acceptable safety. One of the stated goals of the proposal
was to facilitate the introduction of new technologies into small
airplanes. Concepts already envisioned with fly-by-wire system may

render the instruments that were required by former Sec.  23.1303
irrelevant in the future. New Sec.  23.2615 reflects the intent to
allow new technologies in the future, while maintaining a minimum
safety requirement by capturing the safety intent of the former
regulations and by relying on the operating rules and accepted means of
compliance to prescribe the details. This philosophy also applies to
the comment on the phrase ``as needed.'' The accepted means of
compliance, which may include industry consensus standards, will define
which parameters need trends.
    Astronautics asked the FAA to insert a comma after ``as needed'' in
paragraph (a)(1) to clarify that ``as needed'' is a parenthetical
phrase. The FAA agrees and corrects the grammar in the revised rule
language.
    ANAC suggested the FAA not adopt proposed Sec.  23.1310(a) because
it is covered by proposed Sec.  23.1305(b) and (c), which are broader
in scope. In light of the performance-based context of the proposed
rule, ANAC reasoned that defining specific requirements only for
flight, navigation, and powerplant instruments was unnecessary. ANAC
also recommended the FAA not adopt proposed Sec.  23.1310(b), which
appeared to apply to specific technologies (integrated systems). ANAC
noted the intent of paragraph (b) was already addressed in proposed
Sec.  23.1305(b) and (c) (requiring timely information), and proposed
Sec.  23.1315 (now Sec.  25.2510, requiring the capacity to maintain
continued safety flight and landing after single or probable failures).
    The FAA notes ANAC's comment on proposed Sec.  23.1310(a) and (b),
but paragraphs (a) and (b) are not redundant. Sections 23.2505 and
23.2510 apply generally to installed equipment and systems. However,
Sec. Sec.  23.2505 and 23.2510 do not apply if another section of part
23 imposes requirements for specific installed equipment or systems.
The FAA finds that flight, navigation, and powerplant instrumentation
are significant enough to warrant their own requirements. Therefore,
the FAA adopts Sec.  23.1310 (nowSec.  23.2615(a) and (b)) as proposed.
    ANAC also raised concerns that the phrase ``normal, abnormal, and
emergency operation'' in paragraph (a) may be interpreted as a required
classification of types of operations, meaning a system safety type
analysis may be required for each indicator, classification of each
condition, and three separate indications for each condition, which it
deemed overly prescriptive. As an alternative to deleting proposed
Sec.  23.1310(a)(1), ANAC recommended the FAA revise paragraph (a)(1)
to require parameters and trends, as needed, ``to operate the
airplane.''
    The FAA agrees with ANAC and revises paragraph (a)(1) accordingly.
    Genesys Aerosystems commented on proposed Sec.  23.1310(b), which
was formerly covered only in guidance material. Genesys Aerosystems
contended that paragraph (b) is a bit prescriptive and including it in
the regulation could stifle future innovation.
    The FAA notes Genesys Aerosystems concern, but this requirement was
previously covered under former Sec.  23.1311. Section 23.2615(b)
captures the safety intent of former Sec.  23.1311, but removes the
prescriptive requirements of former Sec.  23.1311(a)(5), which mandated
secondary instruments as the means to providing information to the
flightcrew essential for continued safe flight and landing. This would
allow future innovations in system architecture and design to provide
the flight parameters necessary to maintain safe flight.
    EASA recommended moving the pilot interface issues of proposed
Sec.  23.1310 to subpart G.
    The FAA agrees with this recommendation because flightcrew
interface issues are more appropriately addressed in subpart G, which
contains requirements on flightcrew interface and other information.
Therefore, the FAA moves the entire proposed Sec.  23.1310 to subpart G
as new Sec.  23.2615.
f. Airplane Flight Manual (Proposed Sec.  23.1510/Now Sec.  23.2620)
    In the NPRM, proposed Sec.  23.1510 (now Sec.  23.2620) would have
required an applicant to furnish an AFM with each airplane that
contained the operating limitations and procedures, performance
information, loading information, and any other information necessary
for the operation of the airplane.\60\
---------------------------------------------------------------------------

    \60\ The NPRM erroneously stated that proposed Sec.  23.1510 was
intended to consolidate current Sec. Sec.  23.1505 through 23.1527.
See 81 FR at 13495. However, Sec.  23.1510 was actually intended to
consolidate the AFM provisions in former Sec. Sec.  23.1581 through
23.1589.
---------------------------------------------------------------------------

    Garmin noted that the purpose of the AFM is to provide the pilot
with basic information required to safely fly the airplane and stated
it appreciates and supports the FAA's proposal to remove the
prescriptive detail about the AFM content from Sec.  23.1510. However,
Garmin did express concern about use of the phrases ``[o]perating
limits and procedures'' in proposed Sec.  23.1510(a) and ``[a]ny other
information necessary for the operation of the airplane'' in proposed
Sec.  23.1510(d). Garmin noted the possibility for confusion arising
from the ambiguity of the terms ``operating'' and ``operation'' in
former Sec. Sec.  23.1581(a)(2), 23.1581(a)(3), 23.1583(k), and
23.1585(j). For example, Garmin pointed out that many current FAA 20-
series ACs specify that equipment operation limitations should be
included in an AFM.\61\ Garmin contended the AFM was never intended as
a catch-all for equipment or airspace operating limitations and that
equipment operating limitations are more appropriately included in the
equipment's pilot guide or operating manual provided by the equipment
manufacturer.
---------------------------------------------------------------------------

    \61\ As an example, the commenter noted that: AC 20-138D
(including change 1 and 2) for positioning and navigation equipment
includes 77 instances of ``AFM,'' AC 20-165B for ADS-B Out equipment
includes 8 instances of ``AFM,'' AC 20-149B for non-required safety
enhancing FIS-B equipment includes 7 instances of ``A/RFM,'' and
even AC 20-153B for aeronautical database LOAs includes 2 paragraphs
requiring specific AFM content. The commenter noted that these
counts do not include instances of ``airplane flight manual'' or
other similar phrases.
---------------------------------------------------------------------------

    Garmin also suggested using the terms ``operating'' and
``operation'' in proposed Sec.  23.1510(a) and (d) could be easily
confused with operating rule limitations (e.g., Sec.  91.225 for ADS-B
Out) or system-wide operating limitations (e.g., the displayed age of
FIS-B weather products), which are not necessary to safely fly the
airplane and would be more appropriately captured in the Aeronautical
Information Manual (AIM).
    Therefore, Garmin recommended proposed Sec.  23.1510(a) state:
``Airplane operating limitations and procedures.'' The Associations
recommended the same revision. Garmin also suggested revising the NPRM
preamble to state that the AFM is not intended to be used as a catch-
all for equipment operating limitations, or to be used for operating
rule limitations or system-wide operating limitations, all of which are
more appropriately included in guides and manuals.
    The FAA agrees with Garmin in that the AFM was never intended as a
catch-all for equipment or airspace operating limitations. The
requirement for ``operating limitations and procedures'' in the
proposed Sec.  23.1510(a) was intended to capture information required
to be included in the AFM by former Sec. Sec.  23.1583 and 23.1585.
    The FAA did not intend to expand Sec.  23.2620(a) to encompass
information that is not required to be included in the AFM by former
Sec. Sec.  23.1583 and 23.1585. To further clarify its intent, the FAA

adopts the commenters' suggestion and amends Sec.  23.2620(a)(1) to
specify that this section requires ``airplane'' operating limitations
and procedures.
    Proposed Sec.  23.1510(a)(4) would have required that ``any other
information necessary for the operation of the airplane'' must be
included in the AFM. The FAA agrees with the commenters' concern that
the proposed language was too broad and could be interpreted as
requiring information that has not traditionally been included in the
AFM. The intent of this proposed provision was to retain the
requirement of former Sec.  23.1581(a)(2), which require the AFM to
include other information that is necessary for safe operation because
of design, operating, or handling characteristics.'' Because the
proposed language was unclear, the final rule will simply codify,
without change, the language of former Sec.  23.1581(a)(2) into Sec.
23.2620(a)(4).
    Garmin noted that while it was not specifically covered in the NPRM
preamble, it appreciated that proposed Sec.  23.2620 no longer appears
to require FAA approval of certain information contained in the AFM as
required by former Sec.  23.1581(b). Garmin said this would eliminate
delays associated with seeking an Aircraft Certification Office
engineer's approval of AFM content for the TC or STC process, typically
a one-time occurrence; or Flight Standards District Office inspector's
approval of AFM content for post-certification installations, which
occur frequently. Garmin explained that these approval delays translate
into loss of revenue for the applicants. Garmin recommended the
preamble specifically indicate there is no intent to require FAA
approval of AFM content during certification or for post-certification
installation.
    NATCA asked the FAA to clarify the Airworthiness Limitations
Sections (ALS), as well as portions of the AFM, requiring FAA approval.
NATCA indicated this clarification was need as approval of ALS and AFM
content are ``inherently governmental functions.'' NATCA noted that all
other sections of the continuing operating instructions, maintenance,
and some flight manual sections are accepted.
    The FAA notes the requirement for the AFM in former Sec.  23.1581
required each portion of the AFM containing information required by the
FAA must be approved by the FAA, segregated, identified, and clearly
distinguished from each unapproved portion of the AFM. The former
requirements also provided an exception for reciprocating-powered
airplanes that do not weigh more than 6,000 pounds if certain
requirements were met.\62\ It was not the FAA's intent to discontinue
the former requirement to approve select AFM information. The approval
process allows the FAA to review an AFM to ensure it satisfies the
applicable requirements; this rule will generally retain the existing
requirement that FAA-required information provided in the AFM must be
approved by the FAA. For this reason, the FAA has added paragraph (b)
to clarify that the FAA will retain our authority to approve specific
AFM information.
---------------------------------------------------------------------------

    \62\ Id. Sec.  23.1581(b)(2). To qualify for this exception, the
following requirements must be satisfied: (1) Each part of the AFM
containing the Limitations information must be limited to such
information, and must be approved, identified, and clearly
distinguished from each other part of the AFM; and (2) the remaining
required information must be presented in its entirety in a manner
acceptable to the FAA.
---------------------------------------------------------------------------

E. Miscellaneous Amendments (Sec. Sec.  21.9, 21.17, 21.24, 21.35,
21.50, 21.101, SFAR 23, Appendix E to Part 43, and 91.323)
1. Production of Replacement and Modification Articles (Sec.  21.9)
    In the NPRM, the FAA proposed revising Sec.  21.9 by adding a new
paragraph (a)(7) to provide applicants with an alternative method to
obtain FAA approval to produce replacement and modification articles
that are reasonably likely to be installed on type certificated
aircraft. The FAA also proposed revising paragraphs (b) and (c) to
specify that these articles would be suitable for use in a type
certificated product. Lastly, the FAA also proposed allowing an
applicant to submit production information for a specific article, but
would not require the producer of the article to apply for approval of
the article's design or obtain approval of its quality system. Under
the proposed changes, approval to produce a modification or replacement
article under proposed Sec.  21.9(a)(7) would not constitute a
production approval as defined in Sec.  21.1(b)(6). In the NPRM, the
FAA indicated it would limit use of this procedure to articles whose
improper operation or failure would not cause a hazard. Additionally,
the approval would be granted on a case-by-case basis, specific to the
installation proposed, accounting for potential risk and considering
the safety continuum.
    The FAA specifically solicited comments regarding whether the
proposed change would safely facilitate retrofit of low risk articles
and whether there are alternative methods to address the perceived
retrofit barrier.
    All commenters expressed some level of support for the proposed
changes to Sec.  21.9. Several commenters asked the FAA to provide
guidance to clarify how the proposed changes will work.
    The FAA agrees with the commenters that additional details and
clarification are needed to further define the process for obtaining
approval under Sec.  21.9(a)(7) and will provide the necessary policy
and guidance material. Generally, the process for obtaining FAA
approval under Sec.  21.9(a)(7) is intended to be scalable in nature in
that different degrees of substantiation may be required, depending on
the complexity of the article for which approval is sought. For
example, a non-required, low-risk article could be simple enough that a
design approval and quality system might not be required; however, a
more complex article might also require a Sec.  21.8(d) design approval
and some form of quality system. Examples of the requirements for more
complex projects include FAA policy memorandum AIR100-14-110-PM01,
``Approval of Non-Required Angle-of-Attack (AOA) Indicator Systems, and
FAA policy statement PS-AIR-21.8-1602, Approval of Non-Required Safety
Enhancing Equipment (NORSEE).'' For simple articles, a reduction in
scale could be negotiated with the FAA to provide an appropriate level
of safety. Audits of the manufacturer's facility would be at the
discretion of the appropriate MIDO. Typically, a MIDO audit would not
be required unless there is evidence that indicates improper quality
control issues that require a MIDO's involvement, as described in the
FAA Policy Statement PS-AIR-21.8-1602.\63\
---------------------------------------------------------------------------

    \63\ Policy No. PS-AIR-21.8-1602 has been placed in docket
number FAA-20150-1621.
---------------------------------------------------------------------------

    Astronautics Corporation commented that whether an article is
``required'' or ``non-required'' depends on the kind of operation the
applicant requests for certification. Garmin also questioned why the
qualifying articles have to be non-required and asked the FAA to
consider expanding use of the proposed Sec.  21.9(a)(7) process to
include low-risk required articles when the applicant has an approved
quality system. Garmin contended that low risk to the aircraft or its
occupants should be sufficient criteria to allow application to both
required and non-required equipment.
    Astronautics Corporation is correct in its observation that the
approval means for an article could potentially affect the ``kinds of
operation'' authorized for an aircraft. The FAA's intent is not to
bypass existing certification process for required equipment, but to
provide an alternative process for non-required, low-risk articles. For
example, a weather

display approved under Sec.  21.9(a)(7) may have extensive information
available, but this information would be considered supplemental and
could not be used to satisfy operational requirements. If the FAA
determines that certain equipment is required for safety, then existing
certification processes must be followed to ensure the required safety
equipment is functioning properly.
    Garmin also asked what would be needed for approval of the
installation of articles produced under Sec.  21.9(a)(7) and whether
new FAA policy would be needed each time there is a new equipment
standard proposed to allow its installation.
    Section 21.9(a)(7) concerns only the production of articles, not
their installation. The required process for obtaining installation
approval remains unchanged by this rule.
    Garmin asserted that the term ``low risk'' is subjective and asked
the FAA to clarify the intent of this term. Specifically, Garmin asked
if a system with a minor failure condition would fall into the low-risk
category.
    The FAA intends the term ``low risk,'' for the purposes of Sec.
21.9(a)(7), to apply to non-required articles with a hazard
classification no greater than minor. In this context, a ``minor''
failure condition would result in only a slight reduction in functional
capabilities or safety margins.
    Air Tractor asked whether the changes to Sec.  21.9 will apply
equally to TC and STC holders and applicants for those certificates,
which the commenter said it believed the changes should.
    It is the FAA's intent that an article approved under Sec.
21.9(a)(7) can be subsequently approved for installation by a TC or STC
holder based on the installation data provided by the TC or STC holder.
    Additionally, the FAA has decided not to except articles approved
under Sec.  21.9(a)(7) from the prohibition on representing an article
as suitable for installation on a type-certificated product found in
Sec.  21.9(b) and Sec.  21.9(c); therefore, the FAA is not adopting the
NPRM's proposed changes to Sec.  21.9(b) and Sec.  21.9(c). The current
Sec.  21.9 creates an exception from this prohibition for articles
produced under a TC or an FAA production approval because these
articles have approved installation data that justify a representation
of suitability. The proposed changes in the NPRM would have allowed
articles that are not produced under a TC or production approval to be
sold or represented as suitable for installation on type-certificated
products without approved installation data. A representation that an
article is ``suitable for installation'' could be misinterpreted as
``approved for installation.'' The FAA notes that approval under Sec.
21.9(a)(7) does not constitute approval for installation of the
article; however, a person may state that an article approved under
Sec.  21.9(a)(7) may be installed in a type-certificated aircraft
provided it has been determined suitable for installation by an
appropriately-rated mechanic using appropriate means.
2. Designation of Applicable Regulations (Sec.  21.17)
    In the NPRM, the FAA proposed amending Sec.  21.17(a) by removing
the reference to Sec.  23.2 because Sec.  23.2 would be deleted by this
rule.
    NATCA commented that elimination of the reference to retroactive
rules, former Sec.  23.2, leaves holes in certification basis for the
existing fleet of airplanes. This commenter noted that while Sec.  23.2
is not listed as a basis for certification for many existing airplanes,
the provision nevertheless applies due to the date of manufacture of
some airplanes. NATCA also raised concerns it would be burdensome to
revise Type Certificate Data Sheets (TCDS) to reflect the change;
therefore, NATCA requested that this regulation address the addition of
seatbelts as a retroactive, date of manufacture, requirement.
    The FAA notes NATCA's concern; however, the provisions of current
Sec.  23.2 are duplicated in Sec.  91.205 and therefore remain
applicable based on date of manufacture. The revision of TCDS will be
unnecessary because any reference to current Sec.  23.2 in an existing
TCDS will include reference to the applicable amendment and continue to
be enforceable.
    The NTSB commented that the FAA should retain Sec.  23.2 because it
is a regulatory mechanism to apply special retroactive requirements to
newly-manufactured items after the item has been issued a TC.
    The FAA notes the NTSB's comment, but this rule does not affect the
FAA's ability to promulgate other special retroactive requirements
using the normal rulemaking process.
    The FAA removes Sec.  23.2 and revises Sec.  21.17(a) by removing
the reference to Sec.  23.2, as proposed.
    Although the NPRM did not propose changes to Sec.  21.17(b), which
addresses the designation of applicable regulations to special classes
of airplane, NATCA asked whether the FAA would continue to accept
EASA's CS-VLA and CS 22 sailplanes and powered sailplanes, as special,
stand-alone classes of airplanes, or whether the intent was to include
these airplanes in part 23 as EASA proposed.
    The FAA intends to continue to allow CS-VLA and CS 22 airplanes to
be approved as special, stand-alone classes of airplanes while also
allowing eligibility for certification in accordance with part 23 using
accepted means of compliance.
3. Issuance of Type Certificate: Primary Category Aircraft (Sec.
21.24)
    In the NPRM, the FAA proposed amending Sec.  21.24 by revising
paragraph (a)(1)(i) to modify the phrase ``as defined by Sec.  23.49''
to include reference to amendment 23-62 (76 FR 75736, December 2,
2011), effective on January 31, 2012. The FAA explained that revision
would be necessary to maintain a complete definition of stall speed in
Sec.  21.24, as the former Sec.  23.49 is removed by this rule.
    The Associations said it is unnecessary to amend Sec.
21.24(a)(1)(i) as proposed. These commenters noted there are many
references to items such as stall speed that do not need to reference a
previous amendment regulation for the steps to determine stall speed.
The commenters contended it would be sufficient to include the intent
in the preamble discussion.
    The FAA agrees the reference to Sec.  23.49, amendment 23-62, in
Sec.  21.24 is unnecessary. VSO is defined in Sec.  1.2. The
conditions and techniques for determining stall speed have been
consistent for decades. Furthermore, AC 23-8C has a thorough discussion
on how to do stall testing. Rather than referencing a regulation from a
previous amendment, the FAA is revising Sec.  21.24 to refer to
VSO stall speed as determined under part 23.
    The Associations also asked the FAA to include electric propulsion
in the primary category aircraft once the FAA determines acceptable
standards by inserting the phrase ``or with electric propulsion
systems'' after the phrase ``naturally aspired engine.''
    The commenters' request to include electric propulsion systems in
the primary category is beyond the scope of this rulemaking. Therefore,
the FAA defers the request for consideration in future part 21
rulemaking activity.
    NATCA argued the establishment of Primary Category Aircraft in
current Sec.  21.24 has been an almost useless addition to part 21,
resulting in problems without providing any benefit. As an example,
NATCA referenced without elaboration the Seabird Seeker.\64\ NATCA also
noted that very

few airplanes have been certified under existing Sec.  21.24, except
perhaps those seeking to obtain EASA approval for CS-LSA (Light Sport
Aeroplanes). The commenter said the proposed changes to part 23 support
the use of industry specifications as a certification basis within part
23, thereby eliminating the need to retain procedural regulations for
Primary Category Aircraft. NATCA recommended FAA focus on harmonizing
the standards for Very Light Aircraft and Light Sport Aircraft with
bilateral partners, particularly EASA. The commenter observed that
United States manufacturers are at a disadvantage to obtain CS-LSA
approval in Europe.
---------------------------------------------------------------------------

    \64\ It appears the Seabird Seeker is a light utility airplane
built by Seabird Aviation Australia that was prohibited from being
sold in the United States until receiving part 23 TC in 2015.
---------------------------------------------------------------------------

    NATCA maintained that these types of airplanes are meant to be
included in the part 23 rewrite and therefore recommended the FAA
remove new type certification under Sec.  21.24 once the part 23
revisions becomes final. Specifically, NATCA recommended the FAA
rewrite Sec. Sec.  21.24 and 21.184 to eliminate Primary Category
certifications, or keep with an effective date to account for existing
fleet, and create procedural requirements in part 21 and maybe part 23
to recognize something equivalent to EASA's CS-LSA.
    The FAA considered NATCA's proposal to remove Sec.  21.24, in
effect, eliminating primary category certification. Although Very Light
Aircraft and Light Sport Aircraft could be certified under the new part
23, eliminating Sec.  21.24 is beyond the scope of this rulemaking
because it would also remove a means of certification for certain
rotorcraft that qualify for the primary category. These rotorcraft will
not be able to take advantage of the new part 23 because it applies
only to the certification of airplanes. Additionally, Sec.  21.24 and
the new part 23 do not conflict; they are alternative paths for
certification.
    Additionally, proposed Sec.  21.24(i) abbreviated ``January'' as
``Jan''. This rule replaces ``Jan'' with ``January''.
4. Flight Tests (Sec.  21.35)
    The NPRM proposed amending Sec.  21.35(b)(2) to delete reference to
reciprocating engines and expanding the exempted airplanes to include
all low-speed part 23 airplanes 6,000 pounds or less. This proposed
change would align the requirements for function and reliability
testing with the proposed changes in part 23 that do not distinguish
between propulsion types. This change would allow the FAA flexibility
to address new propulsion types.
    All commenters objected to the use of a 6,000-pound weight limit as
a threshold for exemption from testing in proposed Sec.  21.35(b)(2).
Each commenter noted that the stated intent of the part 23 revision is,
in part, to move away from weight and propulsion type classifications.
Each commenter also requested the FAA remove the 6,000-pound weight
limit.
    Air Tractor proposed eliminating the need for function and
reliability testing entirely and suggested the market will sort out
function and reliability issues by means of natural economic controls.
    The Associations suggested the FAA use a parameter other than
maximum weight as a discriminator. Recognizing that the 6,000-pound
weight limit appears to be based on the airplane's complexity and
considering the acceptable level of risk, these commenters suggested
using a low[hyphen]speed airplane, which is a measure of complexity,
and airworthiness level 2 or less, which are newly accepted measures of
risk, to provide the same level of safety. The commenters noted this
discriminator would also better align with the part 23 design rules.
Therefore, the Associations recommended replacing the phrase ``of 6,000
pound or less maximum weight'' with ``meeting part 23 airworthiness
level 1 or 2.''
    The FAA disagrees with Air Tractor's proposal to eliminate all
Function and Reliability (F&R) testing, because elimination of F&R
testing for high-speed, complex airplanes, carrying larger numbers of
passengers is not in keeping with the FAA's statutory mandate to
prescribe minimum standards in the interest of safety for the design
and performance of airplanes.
    The FAA agrees with Textron and the Associations to remove the
6,000-pound discriminator in favor of values based on complexity and
risk. Accordingly, the FAA has decided to replace the exception from
F&R testing for airplanes weighing 6,000 pounds and below with an
exception for airplanes with performance level of low-speed and
certification level of 2 or less. The 6,000-pound discriminator was
based on the FAA's assumptions regarding the complexity and risk
associated with airplanes of that weight. However, as the commenters
point out, their recommended parameters reflect the same assumptions
regarding complexity and risk. Although this change may provide an
exception for airplanes of up to 19,000 pounds, these airplanes would
still be within the allowable risk and complexity parameters.
5. Instructions for Continued Airworthiness and Manufacturer's
Maintenance Manuals Having Airworthiness Limitations Sections (Sec.
21.50)
    In the NPRM, proposed Sec.  21.50(b) would have replaced the
reference Sec.  23.1529 with Sec.  23.1515 to align with the proposed
part 23 numbering convention.
    The FAA has decided not to renumber Sec.  23.1529, which requires
applicants for a TC or a change to a TC under part 23 to prepare
Instructions for Continued Airworthiness; therefore, this section
retains the reference to Sec.  23.1529 in this rule. However, the FAA
will keep the proposed addition of the phrase ``for Continued
Airworthiness'' in the second sentence of Sec.  21.50 to clarify that
the second sentence in paragraph (b) refers to Instructions for
Continued Airworthiness.
6. Designation of Applicable Regulations (Sec.  21.101)
    The NPRM proposed amending Sec.  21.101(b) to remove reference to
Sec.  23.2 because Sec.  23.2 was proposed to be removed from part 23
and the requirements of former Sec.  23.2 are addressed in the
operating rules. The NPRM, in order to align Sec.  21.101 with the
proposed part 23 certification levels, proposed amending Sec.
21.101(c) to include simple airplanes, level 1, low-speed airplanes,
and level 2, low-speed airplanes. The NPRM did not propose to revise
Sec.  21.101 to address airplanes certified under former part 23,
amendment 23-62, or prior amendments. Section 21.101 will continue to
allow for compliance with the certification requirements at amendment
23-62 or earlier when compliance to the latest amendment of part 23 is
determined by the FAA to be impractical.
    The Associations said the FAA should remove the phrase ``to a
simple'' from the first sentence of Sec.  21.101(c), regardless of the
later utilization of the term as these aircraft are completely
encompassed by low[hyphen]speed, level 1 airplanes. The FAA agrees and
revises the rule language to remove ``to a simple'' from Sec.
21.101(c).
    Textron commented that the purpose of the part 23 rewrite is to
move away from prescriptive classifications like weight and propulsion
type, and therefore asked FAA to remove the 6,000-pound weight-based
division in proposed Sec.  21.101(c). Textron also noted the FAA
provided no justifications for retaining the 6,000-pound weight-based
division. Textron also suggested adding

the word ``airplane'' after ``simple'' and after ``level 1 low speed''
for clarity.
    The FAA considered Textron's comment. However, the 6,000-pound
weight division cannot be removed because it continues to apply to
legacy airplanes and modifications to those airplanes. A legacy
airplane would only be identified by a certification level if it was
re-certified to be fully compliant with the new rule. Therefore, the
proposed wording is intended to capture both legacy airplanes and newly
type certified airplanes. The FAA agrees that adding the word
``airplane'' after ``level 1 low speed'' in paragraph (c) will improve
the sentence's clarity.
    NATCA observed that there do not appear to be FAA directives or
guidance on how to apply the part 23 rewrite to existing airplanes. As
an example, NATCA asked how this rewrite would apply to a Piper Seneca
V, an amendment 23-6 airplane. The commenter contended the FAA already
struggles with the existing regulations and guidance. NATCA also asked
how the proposed changes will be implemented on existing TC and STC
products and how the certification basis will be captured. NATCA asked
FAA to issue new directives, orders, and ACs specifically addressing
application of part 23, relative to the Changed Product Rule, to
prevent a situation in which each ACO (and applicant) comes up with
their own creative interpretation of the regulation.
    The FAA has developed internal training and guidance material to
assist FAA employees. Specific to the application of the Changed
Product Rule (Sec.  21.101), there should be minimal variation from
existing procedures and guidance material. The certification basis for
changed products will be captured by section and amendment in
accordance with existing procedures, and section-specific certification
levels identified for those amendments issued concurrent with, or
subsequent to, this rulemaking.
7. Special Federal Regulation 23 (SFAR No. 23)
    This final rule removes SFAR No. 23 as unnecessary because an
applicant may no longer certify an airplane to SFAR No. 23. SFAR No. 23
was first superseded by SFAR 41 and then by commuter category in part
23, amendment 23-34. The FAA's intent to remove SFAR No. 23 was
reflected in the amendatory language in the NPRM.
8. Altimeter System Test and Inspection (Appendix E to Part 43)
    In the NPRM, the FAA proposed to revise paragraph (a)(2) of
appendix E to part 43 by removing the reference to Sec.  23.1325,\65\
which would cease to exist in the proposed rule, and by requiring each
person performing the altimeter system tests and inspections required
by Sec.  91.411 to perform a proof test to demonstrate the integrity of
the static pressure system in a manner acceptable to the Administrator.
This proposed change would have affected owners and operators of part
23 certificated airplanes in controlled airspace under IFR, who must
comply with Sec.  91.411.
---------------------------------------------------------------------------

    \65\ In the NPRM, the FAA proposed to capture the safety intent
of Sec.  23.1325 in proposed Sec. Sec.  23.1300, 23.1310, and
23.1315.
---------------------------------------------------------------------------

    Kestrel noted that existing appendix E to part 43 references Sec.
23.1325 for leakage tolerances; however, the proposed rule would not
have included Sec.  23.1325 and the specified tolerances. Kestrel asked
if the FAA plans to address the specified tolerances in guidance, or if
it will permit the varying tolerances between similar airplane.
    The FAA agrees and will address the leakage tolerances in guidance.
As explained in the NPRM, the FAA is revising AC 43-6, Altitude
Reporting Equipment and Transponder System Maintenance and Inspection
Practices, to include a static pressure system proof test acceptable to
the Administrator. The revised AC will incorporate the same static
leakage standards that were formerly prescribed in Sec.  23.1325.
However, as ACs are not the only means of compliance, it is possible
that someone could ultimately propose an alternative means that the FAA
could find acceptable, which would lead to a difference between similar
airplane. But no such methods have been proposed to date.
9. Increased Maximum Certification Weights for Certain Airplanes
Operated in Alaska (Sec.  91.323)
    The NPRM proposed amendments to Sec. Sec.  91.205, 91.313, 91.323,
and 91.531. The only section that received comments was Sec.  91.323.
increased maximum certification weights for certain airplanes operated
in Alaska.
    The FAA proposed to amend Sec.  91.323 by removing the reference to
Sec.  23.337 because the FAA proposed revising and consolidating Sec.
23.337 with other structural requirements. The FAA proposed adding the
relevant prescriptive requirement of Sec.  23.337 to Sec.
91.323(b)(3).
    Air Tractor noted that the weight in Sec.  91.323(b)(3) has been
changed to reflect a maneuvering load factor that is now independent of
the load factor in part 23, but matches the previous Sec.  23.337
definition. The commenter contended that there is now an increased
likelihood that the load factor considered under this new rule will not
match the load factors that were used in the original certification of
the design, because it is possible that some consensus standard will
impose some other creative interpretation. The commenter suggested that
safety would be better preserved if Sec.  91.323 were required to
reference the load factors that were used in the original
certification.
    Air Tractor's concern is based on an incorrect interpretation of
the FAA's proposed amendment to Sec.  91.323. Section 91.323 applies
only to aircraft that have been type certificated under Airworthiness
Bulletin 7A or under normal category of part 4a of the former Civil Air
Regulations (CAR). The FAA's proposed amendment to Sec.  91.323 would
not permit any additional aircraft to be operated in accordance with
Sec.  91.323. It would only preserve the approval of increased maximum
certification weights for airplanes that were designed and built to a
higher design requirement than CAR 3 and 14 CFR part 23. Approving an
increase in the maximum certificated weight of an airplane pursuant to
Sec.  91.323, based on the equation from former Sec.  23.337(a)(1),
allows operation at the same weights had the airplane been certificated
in accordance with CAR 3.
10. Additional Emergency Equipment (Sec.  121.310)
    In the NPRM, the FAA proposed to amend Sec.  121.310(b)(2)(iii) by
updating the reference to Sec.  23.811(b). Current Sec.
121.130(b)(2)(iii) references Sec.  23.811(b) of part 23, amendment 23-
62. Because the FAA is replacing part 23, amendment 23-62 with new part
23, the FAA proposed to update the reference to Sec.  23.811(b) by
specifying that each passenger emergency exit marking and each locating
sign must be manufactured to meet the requirements of Sec.  23.811(b)
of this chapter in effect on June 16, 1994. However, upon further
reflection, the FAA has decided not to reference a section that will no
longer exist in the CFR on August 30, 2017. Instead, the FAA is
incorporating the requirements of Sec.  23.811(b) in Sec.
121.310(b)(2)(iii). Accordingly, Sec.  121.310(b)(2)(iii) now requires,
for a nontransport category turbopropeller powered airplane type
certificated after December 31, 1964, that each passenger emergency
exit marking and each locating sign be manufactured to have white
letters 1 inch high on a red background 2 inches high, be self-
illuminated or independently, internally electrically illuminated, and
have a

minimum brightness of at least 160 microlamberts. The color may be
reversed if the passenger compartment illumination is essentially the
same.
11. Additional Airworthiness Requirements (Sec.  135.169)
    In the NPRM, the FAA proposed to allow a small airplane in the
normal category, in Sec.  135.169(b)(8), to operate within the rules
governing commuter and on demand operations. Proposed Sec.
135.169(b)(8) would have required the new normal category airplane to
use a means of compliance accepted by the Administrator equivalent to
the airworthiness standards applicable to the certification of
airplanes in the commuter category found in part 23, amendment 23-62.
    Upon further reflection, the FAA has decided not to reference part
23, amendment 23-62 in Sec.  135.169(b)(8) because part 23, amendment
23-62 will not exist in the CFR when new normal category airplanes are
being type certificated under new part 23. The FAA intended proposed
Sec.  135.169(b)(8) to ensure a continued higher level of safety for
commercial operations by requiring a new normal category airplane under
part 23 to use a means of compliance equivalent to the airworthiness
standards that applied to airplanes certified in the commuter category.
As explained in the NPRM, this final rule sunsets the commuter category
for newly type certificated airplanes and creates a new normal
category, certification level 4 airplane as equivalent to the commenter
category by applying it to 10-19 passengers. In order to retain the
FAA's intent while omitting the reference to part 23 at amendment 23-
62, the FAA is revising the proposed rule language to clarify that
Sec.  135.169(b)(8) applies to a normal category airplane equivalent to
the commuter category. Accordingly, Sec.  135.169(b)(8) now allows
consideration of a small airplane that is type certificated in the
normal category, as a multi-engine certification level 4 airplane, to
operate within the rules governing commuter and on demand operations.
    Because new part 23 maintains the level of safety associated with
current part 23, except for areas addressing loss of control and icing
where a higher level of safety is established, the FAA expects that any
multi-engine, level 4 airplane approved for commercial operations with
10 or more passengers will meet, at a minimum, the performance required
for airplanes type certificated in the commuter category.

IV. Regulatory Notices and Analyses

A. Regulatory Evaluation Summary

    Changes to Federal regulations must undergo several economic
analyses. First, Executive Order 12866 and Executive Order 13563 direct
that each Federal agency shall propose or adopt a regulation only upon
a reasoned determination that the benefits of the intended regulation
justify its costs. Second, the Regulatory Flexibility Act of 1980 (Pub.
L. 96-354) requires agencies to analyze the economic impact of
regulatory changes on small entities. Third, the Trade Agreements Act
(Pub. L. 96-39) prohibits agencies from setting standards that create
unnecessary obstacles to the foreign commerce of the United States. In
developing U.S. standards, this Trade Act requires agencies to consider
international standards and, where appropriate, that they be the basis
of U.S. standards. Fourth, the Unfunded Mandates Reform Act of 1995
(Pub. L. 104-4) requires agencies to prepare a written assessment of
the costs, benefits, and other effects of proposed or final rules that
include a Federal mandate likely to result in the expenditure by State,
local, or tribal governments, in the aggregate, or by the private
sector, of $100 million or more annually (adjusted for inflation with
base year of 1995). This portion of the preamble summarizes the FAA's
analysis of the economic impacts of this final rule. We suggest readers
seeking greater detail read the full regulatory evaluation, a copy of
which we have placed in the docket for this rulemaking.
    In conducting these analyses, FAA has determined that this final
rule: (1) Has benefits that justify its costs, (2) is not an
economically ``significant regulatory action'' as defined in section
3(f) of Executive Order 12866, (3) is not ``significant'' as defined in
DOT's Regulatory Policies and Procedures; (4) has a significant
positive economic impact on small entities; (5) will not create
unnecessary obstacles to the foreign commerce of the United States; and
(6) will not impose an unfunded mandate on state, local, or tribal
governments, or on the private sector by exceeding the threshold
identified above. These analyses are summarized below.
1. Total Benefits and Costs of This Rule
    The following table shows the estimated benefits and costs of the
final rule. Another way to consider the expected net benefit to the
society is if the rule saves only one human life by improving stall
characteristics and stall warnings, this alone would result in benefits
which substantially outweigh the costs.

                      Estimated Benefits and Costs
                            [2015 $ Millions]
------------------------------------------------------------------------
                                                      Safety benefits +
                              Stall & spin + other  cost savings = total
                                      costs               benefits
------------------------------------------------------------------------
Total.......................  $0.8 + $3.1 = $3.9..  $17.9 + $9.9 = $27.8
Present value at 7%.........  0.8 + 3.1 = 3.9.....  6.1 + 4.9 = 11.0
Present value at 3%.........  0.8 + 3.1 = 3.9.....  11.1 + 7.1 = 18.3
------------------------------------------------------------------------
* These numbers are subject to rounding error.

2. Who is potentially affected by this rule?
    The proposal will affect U.S. manufacturers and operators of new
part 23 type certificated airplanes.
3. Assumptions
    The benefit and cost analysis for the regulatory evaluation is
based on the following factors/assumptions:
     The analysis is conducted in constant dollars with 2015 as
the base year.
     The final rule will be effective in 2017.
     The primary analysis period for costs and benefits extends
for 20 years, from 2017 through 2036. This period was selected because
annual costs and benefits will have reached a steady state by 2036.
     Future part 23 type certifications and deliveries are
estimated from historical part 23 type certifications and deliveries.
     Costs for the new part 23 type certifications forecasted
in the ``Fleet Discussion'' section will all occur in year 1 of the
analysis interval.

     Airplane deliveries from the forecasted part 23 type
certificates will start in year 5 of the analysis interval. Therefore,
accident reduction benefits will begin five years after the rule is in
effect.
     The FAA uses a three and seven percent discount rate for
the benefits and costs as prescribed by OMB in Circular A-4.
     The baseline for estimating the costs and benefits of the
rule will be part 23, through the current amendment level.
     Based on FAA Small Airplane Directorate expert judgment,
the FAA estimates 335 FAA part 23 certification engineers will require
additional training as a result of this final rule. The FAA assumes
that the same number of industry part 23 certification engineers will
also require additional training as a result of this final rule.
     The FAA estimates this rulemaking will add 16 hours of
training to FAA and industry part 23 certification engineers.
     Since this training program will be on-line, we estimate
no travel costs for the engineers.
     FAA pay-band tables and the Bureau of Labor Statistics
(BLS) determines the hourly wages used to estimate the costs to the FAA
and applicants.
     Using the U.S. Department of Transportation guidance, the
wage multiplier for employee benefits is 1.17.
4. Benefits of This Rule
    The major safety benefit of this rule is to add stall
characteristics and stall warnings that will result in airplane designs
that are more resistant to inadvertently departing controlled flight.
The largest number of accidents for small airplanes is a stall or
departure based loss of control (LOC) in flight. This rule will have
cost savings by streamlining the certification process and encouraging
new and innovative technology. Streamlining the certification process
will reduce the issuance of special conditions, exemptions, and
equivalent level of safety findings.
5. Costs of This Rule
    The final rules major costs are the engineer training costs and the
certification database creation costs. Additional costs will also
accrue from the controllability and stall sections that will increase
scope over current requirements and manual upgrade costs.
    In the following table, we summarize the total estimated compliance
costs by category. The FAA notes that since we assumed that all costs
occurred in Year 1 of the analysis interval, the 2015-dollar costs
equal the present value costs.

                     Total Cost Summary by Category
                     [In 2015 present value dollars]
------------------------------------------------------------------------
                                                          Total costs in
                      Type of cost                         present value
                                                           at 7 percent
------------------------------------------------------------------------
Sec.   23.2150(c) Controllability.......................        $277,318
Sec.   23.2150(b) Stall characteristics, stall warning,          500,595
 and spins..............................................
Engineer Training Costs.................................       1,167,379
Certification Database Costs............................       1,295,290
Manual Upgrade Costs....................................         700,833
                                                         ---------------
  Total Costs...........................................       3,941,414
------------------------------------------------------------------------
* These numbers are subject to rounding error.

B. Final Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA)
establishes ``as a principle of regulatory issuance that agencies shall
endeavor, consistent with the objectives of the rule and of applicable
statutes, to fit regulatory and informational requirements to the scale
of the businesses, organizations, and governmental jurisdictions
subject to regulation. To achieve this principle, agencies are required
to solicit and consider flexible regulatory proposals and to explain
the rationale for their actions to assure that such proposals are given
serious consideration.'' The RFA covers a wide-range of small entities,
including small businesses, not-for-profit organizations, and small
governmental jurisdictions.
    Agencies must perform a review to determine whether a rule will
have a significant economic impact on a substantial number of small
entities. If the agency determines that it will, the agency must
prepare a regulatory flexibility analysis as described.
    The FAA believes that this final rule could have a significant
positive economic impact on a substantial number of entities because we
believe this rule could enable the creation of new part 23 type
certificates and new manufacturers. The FAA has been working with U.S.
and foreign small aircraft manufacturers since 2007 to review the life
cycle of part 23 airplanes and determine what needed improvement.
    The purpose of this analysis is to provide the reasoning underlying
the FAA determination.
    Section 604(a) of the Act specifies the content of a FRFA.
    Each FRFA must contain:
     A statement of the need for, and objectives of, the rule;
     a statement of the significant issues raised by the public
comments in response to the initial regulatory flexibility analysis, a
statement of the assessment of the agency of such issues, and a
statement of any changes made in the proposed rule as a result of such
comments;
     the response of the agency to any comments filed by the
Chief Counsel for Advocacy of the Small Business Administration in
response to the proposed rule, and a detailed statement of any change
made to the proposed rule in the final rule as a result of the
comments;
     a description of and an estimate of the number of small
entities to which the rule will apply or an explanation of why no such
estimate is available;
     a description of the projected reporting, recordkeeping
and other compliance requirements of the rule, including an estimate of
the classes of small entities which will be subject to the requirement
and the type of professional skills necessary for preparation of the
report or record; and
     a description of the steps the agency has taken to
minimize the significant economic impact on small entities consistent
with the stated objectives of applicable statutes, including a
statement of the factual, policy, and legal reasons for selecting the
alternative adopted in the final rule and why each one of the other
significant alternatives to the rule considered by the agency which
affect the impact on small entities was rejected.
1. Reasons Why the Rule Is Needed
    The FAA promulgates this action to amend the airworthiness
standards for new part 23 type certificated airplanes to reflect the
current needs of the small airplane industry, accommodate future
trends, address emerging technologies, and enable the creation of new
part 23 manufacturers and new type certificated airplanes. The rule's
changes to part 23 are necessary to eliminate the current workload of
exemptions, special conditions, and equivalent levels of safety
findings necessary to certificate new part 23 airplanes. These part 23
changes will also promote safety by enacting new regulations for
controllability and stall standards and promote the introduction of new
technologies in part 23 airplanes.
2. Significant Issues Raised by the Public Comments in Response to the
Initial Regulatory Flexibility Analysis
    With regard to assessing the impact on small, numerous firms were
left out

of the FAA's analysis. Analysis concerning the impact on small firms
ultimately included data from only 5 firms, one of which has not been
in operation for 8 years, and another that no longer exists, but is
struggling to set up business under new ownership. It would seem that
the FAA should have knowledge of every company that still has active
manufacturing activities (active production certificates), and that the
data that was included was exceptionally non-representative of the
overall industry. Further, by eliminating from consideration all firms
that are not US-owned a distorted view of the true impact on the
general aviation industry in our country is presented.
    FAA Response: Under the Small Business Regulatory Flexibility Act,
for each initial regulatory flexibility analysis, agencies are required
to provide a description of and, where feasible, an estimate of the
number of small entities to which the proposed rule would apply. Many,
if not most, small entities do not provide public data such as
publically available employment data in order to determine if a
business is small under the SBA guidelines, or publically available
revenue data, in order to determine if a business is disproportionately
burdened by the proposed or final rulemaking. The FAA does not have the
means or authority to require small entities to report their employment
or revenue data and therefore we do not have knowledge of every company
that still has active manufacturing activities. The small business
entities that the FAA analyzed provided data on their employment and
revenue either through the U.S. DOT Form 41 rules, SEC rules, or
through news releases the companies made public.
    The FAA conducted research and found that all five businesses' we
examined at the time of our analysis were small and either actively
manufacturing aircraft or they were under new ownership and had
publically announced they were in the process of working towards
setting up an aircraft manufacturing line. The FAA notes the rule also
reduces the certification time for small part 23 parts manufacturers.
The FAA conclusion that the proposed rule may have a significant
positive impact on small entities extends well beyond our sample.
    Further, FAA regulations apply to US-owned business and to any
foreign owned business that manufactures a product in the U.S. or
markets their products/services in the U.S. Foreign owned business'
voluntarily complies with the rules and regulations promulgated by the
FAA. Thus the FAA expects that the final rule would impact a
substantial number of small entities.
    The comment regarding numerous firms being left out of the FAA's
small business analysis was from a company who certificates most of
their aircraft with a restricted category special air worthiness
certificate. A restricted category special airworthiness certificate is
issued to operate aircraft that have been type certificated in the
restricted category. Operation of restricted category aircraft is
limited to special purposes identified in the applicable type design.
Restricted category aircraft manufacturers do not follow part 23 in its
entirety, rather they follow parts of part 21, part 21 subpart H, part
45, section 91.313, part 91 subpart D, section 91.715, and part 375 and
can choose whatever other certification bases requirements, based on
FAA approval, to certificate their aircraft for the aircraft's special
operations. Therefore, since restricted category aircraft manufacturers
do not comply part 23 in its entirety for their type certifications,
these manufacturers are not included in our analysis.
    In addition, many part suppliers may benefit from this performance-
based rule through an expected quicker approval process. The objective
of this rule is to allow industry more flexibility and lower cost
methods to certify future part 23 airplanes at a sufficiently lower
certification cost which can be driven by industry innovation and more
small entities will have additional opportunities that do not exist
today.
3. FAA Response to Any Comments Filed by the Chief Counsel for Advocacy
of the Small Business Administration in Response to the Proposed Rule
    The Chief Counsel for Advocacy did not file comments for the
proposed rule.
4. A Description of and an Estimate of the Number of Small Entities to
Which the Rule Will Apply or an Explanation of Why No Such Estimate Is
Available
    For the initial regulatory flexibility analysis (IRFA), the FAA
conducted a review to determine whether a rule will have a significant
economic impact on a substantial number of small entities. The IRFA
concluded that the proposed rule could have a significant economic
impact on a substantial number of entities because we believe this rule
could enable the creation of new part 23 type certificates and new
manufacturers.
    The FAA is unable to estimate the total number of small entities to
which the rule will apply because many, if not most, small part 23
aircraft manufacturing entities do not provide public data such as
publically available employment data in order to determine if a
business is small under the SBA guidelines, and publically available
revenue data, in order to determine if a business is disproportionately
burdened by the final rulemaking. The FAA also believes that the final
rule will enable new part 23 aircraft manufacturing industries, while
maintaining a safe operating environment. In addition, many part
suppliers may benefit from this performance-based rule through an
expected quicker approval process.
5. A Description of the Projected Reporting, Recordkeeping and Other
Compliance Requirements of the Rule, Including an Estimate of the
Classes of Small Entities Which Will Be Subject to the Requirement and
the Type of Professional Skills Necessary for Preparation of the Report
or Record
    The final rule will reduce the number of special conditions,
equivalent level of safety (ELOS), and exemptions and therefore will
reduce paperwork and processing time for both the FAA and industry. The
rule would also maintain the fundamental safety requirements from the
current part 23 regulations but allow more flexibility in airplane
designs, faster adoption of safety enhancing technology, and reduce the
regulatory cost burden. To estimate savings driven by this change, the
FAA counted the special conditions, ELOS, and exemption applications
submitted to the FAA for part 23 aircraft between 2012 and 2014 and
divided the number by two years for an average of 37 applications per
year. The Aviation Rulemaking Committee (ARC) report offered a similar
average of 37 applications per year. Additionally, the FAA counted the