device that complies with Sec.  25.1303(c)(1) or airworthiness criteria
that the FAA has determined provides an equivalent level of safety in
accordance with Sec.  21.17(b).
    Section 91.605 prescribes transport category civil airplane weight
limitations. Powered-lift are capable of performing both vertical
takeoffs and landings, and takeoffs and landings using wing-borne lift
similar to an airplane. The FAA proposes that certain provisions in
Sec.  91.605 apply to large powered-lift to ensure those aircraft can
safely takeoff and land in accordance with the performance information
in the Aircraft Flight Manual and taking into consideration altitude
and temperature. This application of the rule provides flexibility to
operators seeking to maximize the novel capabilities of powered-lift
while maintaining a high level of operational safety.
    Section 91.605(a) prescribes takeoff requirements for transport
category airplanes (other than a turbine-engine-powered airplane
certificated after September 30, 1958). This regulation applies only to
non-turbine powered airplanes that were type certificated without an
Airplane Flight Manual. All new entrant powered-lift type certificated
under Sec.  21.17(b) will be required to have an Aircraft Flight
Manual; accordingly, the FAA does not propose to apply Sec.  91.605(a)
to powered-lift for this SFAR.
    Section 91.605(b) contains references to an Airplane Flight Manual
and prohibits operations contrary to the flight manual. Section
91.605(b)(1) states that no person operating a turbine-engine-powered
transport category airplane may take off that airplane at a weight
greater than that listed in the Airplane Flight Manual. The calculation
for determining that takeoff weight must consider the elevation of the
airport and the ambient temperature existing at the time of takeoff.
This regulation provides an important performance criterion to ensure
that operators of an aircraft consider the effects of altitude and
temperature when determining the maximum allowable takeoff weight. The
effects of altitude and temperature are important to consider because
aircraft performance is reduced as the altitude and the temperature is
increased. This is especially true for takeoff operations, where an
increase in altitude and temperature causes a decrease in aircraft
performance. An increase in altitude and temperature also causes an
increase in takeoff distance required and a decrease in the maximum
allowable takeoff weight. Adherence to the performance limitations in
the Aircraft Flight Manual is critical for the safe operation of any
aircraft, including powered-lift whose performance is also negatively
impacted by increased altitude, temperature, and weight. Therefore, the
FAA proposes in Sec.  194.302(mm) to apply Sec.  91.605(b)(1) to large
powered-lift--regardless of whether they will takeoff vertically or
using wing-borne lift similar to an airplane--and that have the takeoff
performance information in the aircraft flight manual.
    Section 91.605(b)(2) stipulates no person operating a turbine-
engine-powered transport category airplane may take off at a weight
(allowing for normal consumption of fuel and oil in flight to the
destination or alternate airport) if the weight of the airplane on
arrival would exceed the landing weight as contained in the Airplane
Flight Manual taking in consideration the elevation of the destination
or alternate airport and the ambient temperature anticipated at the
time of landing. As described in the previous paragraph, these
computations must include the elevation of the take-off and the ambient
temperature at the time of takeoff. This regulation establishes an
important pre-takeoff planning criterion that must consider the maximum
landing weight to ensure that the airplane is at a weight that will
allow a landing that is within the performance capabilities of that
aircraft. The FAA proposes in Sec.  194.302(nn) that paragraph (b)(2)
apply to large powered-lift--regardless of whether they will land
vertically or using wing-borne lift similar to an airplane--and that
have the landing performance information in the aircraft

flight manual. Applying this paragraph will help ensure that large
powered-lift are operated at the same level of safety required for
transport category airplanes.
    Section 91.605(b)(3) and (b)(4)(ii) also contain additional takeoff
criteria for turbine-engine-powered transport category airplanes, such
as wet runway and clearway distances. The FAA proposes in Sec.
194.302(oo) to apply these requirements to certain large powered-lift
to ensure that published flight manual limitations are not exceeded
when powered-lift execute takeoff operations that utilize wing-borne
lift, similar to an airplane, and have that takeoff performance
information contained in the flight manual. The FAA proposes paragraphs
(b)(3) and (b)(4)(ii) apply to large powered-lift that execute takeoff
operations using wing-borne lift and that have takeoff performance
information in the flight manual.
    Section 91.605(c) sets specific requirements for takeoff distances
and runway lengths for turbine-engine-powered transport category
airplanes certificated after August 29, 1959. The FAA considers that
these provisions are equally important and necessary for powered-lift
to safely execute takeoff operations that utilize wing-borne lift. The
FAA proposes (also in Sec.  194.302(oo)) that this paragraph apply to
large powered-lift executing takeoff operations that utilize wing-borne
lift and have takeoff performance information in the aircraft flight
manual.
    Section 91.609 sets forth requirements for FDR and cockpit voice
recorder (CVR) in large and transport category aircraft. Section
91.609(a) and (b) already apply to powered-lift because those
paragraphs apply to ``aircraft.'' Paragraphs (f), (g), and (k) also
already apply to operators of powered-lift who are otherwise required
by part 194 to comply with this section. Section 91.609(c)(1) requires
that a multi-engine, turbine-powered airplane or rotorcraft having a
passenger seating configuration, excluding any pilot seat, of 10 or
more, that has been manufactured after October 11, 1991, unless it is
equipped with one or more approved flight recorders that utilize a
digital method of recording and storing data and a method of readily
retrieving that data from the storage medium. Additionally, this
paragraph requires that the flight recorder must retain no less than 8
hours of aircraft operation. The FAA proposes in Sec.  194.302(pp) that
a powered-lift, regardless of the type of powerplant, that otherwise
meets the threshold requirements of this paragraph be required to
comply with this paragraph. However, Sec.  91.609(c)(1) specifies that
the parameters for the flight recorder that must be recorded are
contained in part 91, appendix E or F, which are specific to airplanes
or helicopters. As stated previously, many powered-lift will be
manufactured combining the design features of an airplane and
helicopter, to varying degrees. In place of appendices E and F to part
91,\373\ the FAA has drafted new FDR tables for part 194,\374\ which
outline the FDR specifications for powered-lift under part 91, in
proposed Sec. Sec.  194.312 and 194.313. In developing these tables,
the FAA applied the FDR requirements from the airplane and helicopter
appendices to powered-lift, dependent on which operational flight mode
is in use (i.e., wing-borne flight mode or vertical-lift flight mode).
In addition, the FAA replaced helicopter-specific nomenclature to
accommodate powered-lift. For example, helicopter flight controls, as
written, describe pedals and collective controls, which may not apply
to powered-lift. In addition, the FAA changed the terminology that
provided directional controls for ``ascent and descent''.
Notwithstanding slight nomenclature changes within the parameters, the
FAA did not change the other information and numbers within the tables.
The FAA invites comments on these new draft tables to ensure that the
FAA has adequately addressed all of the requirements for these novel
aircraft.
---------------------------------------------------------------------------

    \373\ See appendix E to part 91, Airplane Flight Recorder
Specifications, and appendix F to part 91, Helicopter Flight
Recorder Specifications, 14 CFR part 91.
    \374\ The SFAR tables are found in the regulatory text within
the SFAR amendment.
---------------------------------------------------------------------------

    Section 91.609(c)(3) requires that all airplanes and rotorcraft
subject to Sec.  91.609(c)(1) manufactured on or after April 7, 2010,
must meet the FDR requirements of Sec.  23.1459, Sec.  25.1459, Sec.
27.1459, or Sec.  29.1459, as applicable, and retain at least the last
25 hours of recorded information using a recorder that meets the
standards of TSO-C124a, or later revision. The FAA proposes in Sec.
194.302(pp) that powered-lift comply with this requirement to provide a
level of safety equivalent to airplanes and rotorcraft.
    Section 91.609(d) requires that whenever a flight recorder required
by Sec.  91.609 is installed, it must be operated continuously from the
instant the airplane begins the takeoff roll or the rotorcraft begins
lift-off until the airplane has completed the landing roll or the
rotorcraft has landed at its destination. The FAA proposes in Sec.
194.302(pp)(3) to require powered-lift to comply with this section by
requiring that the flight recorder be operated continuously from the
earlier of when the powered-lift begins the takeoff roll or begins
lift-off until the latter of when the powered lift has completed the
landing roll or has landed at its destination. This will ensure the
same level of safety is provided for powered-lift as exists in the
current regulations for airplanes and rotorcraft.
    Section 91.609(e) requires that unless otherwise authorized by the
Administrator, after October 11, 1991, no person may operate a U.S.
civil registered multiengine, turbine-powered airplane or rotorcraft
having a passenger seating configuration of six passengers or more and
for which two pilots are required by type certification or operating
rule unless it is equipped with an approved CVR. CVRs enhance safety
and are required in turbine-powered airplanes and rotorcraft carrying a
certain passenger count as a necessary hazard analysis tool used during
an accident investigation. As early as 1978, the FAA has noted that
consideration should be given to requiring Ground Proximity Warning
Systems (GPWS), CVR, and FDR equipment on turbojet-powered airplanes
with 10 or more passenger seats due to the complexity and high-
performance characteristics of those airplanes.\375\ These sources of
information aid in determining causal and contributing factors in
accident and incident investigation. Amendments issued in response to
NTSB recommendations as well as congressional mandates identify the
FAA's broader responsibility to apply these appropriately to all
aircraft with certain seating capacities.\376\ The CVR provides
accident investigation information that is unattainable from any other
source with valuable auditory information such as sounds captured in
the cockpit. Accordingly, the FAA proposes in Sec.  194.302(pp),
regardless of the type of powerplant, that powered-lift which have a
passenger seating configuration of six or more and for which two pilots
are required by type certification or operating rules, will be required
to comply with all the paragraphs of paragraph (e). This will ensure
that powered lift operate as safely as airplanes and rotorcraft.
---------------------------------------------------------------------------

    \375\ See Regulatory Review Program; Air Taxi Operators and
Commercial Operators, 43 FR 46742, 46768 (Oct. 10, 1978).
    \376\ Id. at 46742.
---------------------------------------------------------------------------

    Section 91.609(h) is applicable to legacy airplanes certificated
before April 7, 2010. It cannot apply to new entrant aircraft and is
accordingly not applicable to powered-lift.

    Section 91.609(i) and (j) apply to both airplanes and rotorcraft.
The FAA considers CVRs and FDRs to be necessary safety equipment on
airplanes and rotorcraft and proposes in Sec.  194.302(pp) that these
requirements also be applicable to powered-lift. The same concerns
regarding ensuring data is recorded from the cockpit or flight in the
event of an accident or incident are true for powered lift as they are
for airplanes and helicopters.
    Section 91.611 authorizes ferry flights with one engine inoperative
for airplanes with three or four engines. The rule was written
specifically for airplanes and is based on airplane performance
characteristics. The FAA acknowledges that some powered-lift may
operate as an airplane during takeoff but determined this section
should not be applicable to large powered-lift under the SFAR due to
the lack of data to support safe powered-lift operations with an
inoperative engine. The FAA expects to obtain more data during the term
of this SFAR to determine if powered-lift can safely operate with an
inoperative engine.
    Section 91.613 requires airplane compartment interiors to meet the
flame propagation requirements set forth in Sec.  25.853 or Sec.
25.856. The part 25 certification standard for flame propagation
materials reduces the spread of fire within the aircraft and in the
event of a post-crash fire, as well as reducing the penetration of fire
for an external source such as an engine firewall. Section 91.613(b)(2)
is applicable to transport category airplanes manufactured after
September 2, 2005 and the FAA proposes in Sec.  194.302(qq) that it be
applied to powered-lift of similar size and capacity under the SFAR due
to the safety mitigations this rule provides. For large powered-lift,
the FAA proposes that the thermal/acoustic installation materials
required by Sec.  91.613(b)(2) meet the requirements of Sec.  25.856 or
such airworthiness criteria as the FAA may find provide an equivalent
level of safety in accordance with Sec.  21.17(b). Section 91.613(a)
does not apply to powered-lift because SFAR 41 terminated in September
1983 and is limited to type design changes for airplanes issued prior
to October 1979.
7. Subpart K--Fractional Ownership Operations
    Subpart K was added to part 91 in 2003 to establish criteria for
fractional ownership programs. It allows fractional owners and the
management company to share operational control of the aircraft and
delineates operational control responsibilities. It also contains
regulatory safety standards for operations under fractional ownership
programs, including management operations, maintenance, training, and
crewmember flight and duty requirements. Subpart K currently has two
powered-lift references in Sec. Sec.  91.1001(b)(10) and 91.1053(a)(2).
These references were included when part 91 subpart K was codified to
prescribe specific applicability and crew training requirements for
fractional ownership operations. Pilot training and qualification
requirements under this subpart are discussed in section V of this
preamble. In addition to the specific powered-lift references, many
subpart K sections impose requirements on aircraft, which include
powered-lift.
    As stated in section V.L of this preamble, the following sections
of subpart K will apply to large powered-lift without regard to type of
powerplant.
    Section 91.1025 prescribes program operating manual contents. The
manual must set forth the program's procedures and policies to ensure
the safe operation of the aircraft they use. The manual content
requirements of a Destination Airport Analysis specified in Sec.
91.1025(o) are only required if the aircraft meets the thresholds set
forth Sec.  91.1037, Large transport category airplanes: Turbine engine
powered; Limitations; Destination and alternate airports. The FAA
anticipates some powered-lift will be manufactured in a way that would
trigger the safety requirements of Sec.  91.1037. This section is
already applicable to powered-lift that operate under subpart K;
however, the FAA also clarifies that if a specific powered-lift meets
the requirements of Sec.  91.1037, then all of the requirements of
Sec.  91.1025(o), including Sec.  91.1025(o)(7) which currently only
applies to airplanes, would be applicable as well, as set forth in
Sec.  194.302(rr). This proposal will ensure that an adequate level of
safety is maintained for powered-lift that meet the performance
requirements of Sec.  91.1037, and that any inoperative equipment is
considered when Destination Airport Analysis is performed.
    Section 91.1037 addresses large transport category airplanes and
should apply to large powered-lift. The FAA perceives that large
powered-lift will operate similar to large transport-category airplanes
when considering altitude, distance, speed, passenger carrying
capacity, passenger safety, composition of flight crew, operating
environment (e.g., over water), and required safety and rescue
equipment. Specifically, Sec.  91.1037(e) requires that, unless based
on a showing of actual operating landing techniques on wet runways, a
shorter landing distance (but never less than that required by
paragraph (b) or (c)) has been approved for a specific type and model
airplane and included in the Airplane Flight Manual, no person may take
off a turbojet airplane when the appropriate weather reports or
forecasts, or any combination of them, indicate that the runways at the
destination or alternate airport may be wet or slippery at the
estimated time of arrival unless the effective runway length at the
destination airport is at least 115 percent of the runway length
required under paragraph (b) or (c). The FAA anticipates that due to
the VTOL capabilities of powered-lift, many of these aircraft may not
need to compute a landing distance as required by this section.
However, certain powered-lift may conduct landing operations similar to
an airplane. Accordingly, the FAA proposes in Sec.  194.302(rr) this
entire section be applicable to large powered-lift that are
certificated to conduct landing operations in wing-borne flight mode as
indicated in the aircraft flight manual.
    Section 91.1039(c) prohibits a pilot on a program aircraft
operating a program flight from beginning an instrument approach
procedure to an airport unless the MDA or Decision Altitude (DA) and
visibility landing minimums prescribed in part 97 or in the program
manager's management specifications are increased by 100 feet and 1-2
mile respectively, but not to exceed the ceiling and visibility
minimums for that airport when used as an alternate airport, for each
PIC of a turbine-powered aircraft who has not served at least 100 hours
as PIC in that type of aircraft. This regulation is based on Sec.
135.225(e), and was incorporated into the subpart K rules for
Fractional Ownership operations because the FAA considered that the
safe execution of an instrument approach to the lowest minimums
requires the highest degree of pilot familiarity with the airplane, its
controls, instruments, and performance characteristics, and that 100
hours of experience in a new type of airplane as PIC in air carrier or
commercial operations is necessary in order to achieve this degree of
familiarity. This familiarity requirement is still relevant to
operations conducted in airplanes today and pilots of all powered-lift
should also possess the highest degree of familiarity with their
aircraft, its controls, instruments, and performance requirements, not
only those operating turbine-powered powered-lift. The FAA

also anticipates the pilots of any powered-lift will experience an
additional workload as the aircraft transitions from wing-borne to
vertical-lift flight, during the landing phase while in reduced
visibility. The FAA is proposing that the PIC of all powered lift
operating under subpart K increase the MDA or DA and visibility landing
minimums as required by Sec.  91.1039(c), as set forth in proposed
Sec.  194.304.
    Section 91.1041 addresses aircraft proving and validation tests.
Section 91.1041 sets out the parameters and the requirements for when
Proving and Validation Tests must be accomplished by a fractional
ownership program. Proving tests are necessary to evaluate each
fractional ownership program's ability to conduct operations safely and
in accordance with the applicable regulations. Proving tests, under
Sec.  91.1041, consist of a demonstration of the fractional ownership
program's ability to operate and maintain certain aircraft new to the
operator's fleet or the certificate holder's ability to conduct a
particular kind of operation. Additionally, it is each fractional
ownership program manager's responsibility to show that each aircraft
can be operated safely and in compliance with the regulations and their
procedures.
    Section 91.1041(b) requires a fractional ownership program manager
to conduct proving tests in a turbojet airplane if they have not
previously proved a turbojet airplane. The FAA expects powered-lift,
regardless of the powerplant, to have additional complexity due to
their design and operation, and that these features have not been
available and experienced by the civilian market to date. To ensure a
high level of safety is maintained when these aircraft are operated,
the FAA is proposing in Sec.  194.302(ss) that a fractional ownership
program manager that has not previously proven a powered-lift in
operations under subpart K, be required to conduct at least 25 hours of
proving tests acceptable to the Administrator as detailed in Sec.
91.1041(b)(1) through (3).
    The FAA requires validation testing for certain authorizations, and
for the addition of certain aircraft that were previously proved or
validated but are not of the same make or model, or of similar design.
These tests are required for aircraft that require two pilots for
flight in VFR conditions, or turbojet airplanes. For the same reasons
cited above for proving tests, validation testing required by Sec.
91.1041(d) should be applicable to all powered-lift. The FAA proposes
in Sec.  194.302(ss) that validation testing be required when a program
manager requests authorization to use a powered-lift, unless a powered-
lift of the same make or similar design has been previously proved or
validated by that program manager in operations under subpart K.
    Section 91.1045 contains additional safety equipment requirements
for program aircraft. The FAA is proposing that this rule apply to
powered-lift in proposed Sec.  194.302(tt). For powered-lift with more
than 30 seats or a payload capacity of more than 7,500 pounds, the FAA
proposes that Sec.  91.1045(a) applies; and for powered-lift with 30
seats or fewer and a payload capacity of 7,500 pounds or less, Sec.
91.1045(b) applies.
    Section 91.1045(a)(3) and (b)(3) specify TAWS as the required
terrain awareness and warning system requirement. The FAA considered
both TAWS and HTAWS because of powered-lift's ability to operate
similar to both airplanes and helicopters. The FAA determined that the
current HTAWS specification would provide the best level of safety
without an undue number of nuisance warnings. The FAA proposes that
Sec.  91.1045(a)(3) and (b)(3) apply to powered-lift, and that powered-
lift comply with the requirements in Sec.  194.307(q) of this SFAR. For
further discussion of the FAA's proposal regarding TAWS vs. HTAWS,
please see VI.B.
    Section 91.1045(b)(5) refers to airborne thunderstorm detection
equipment required by Sec.  135.173 or airborne weather radar required
by Sec.  135.175, as applicable to the aircraft specified in each
section. This section is applicable to airplanes having a passenger-
seat configuration of 30 seats or fewer, excluding each crewmember, and
a payload capacity of 7,500 pounds or less, and any rotorcraft (as
applicable). The use of airborne thunderstorm detection equipment or
airborne weather radar contributes to greater safety in operations
because it enables the pilot to detect and locate severe adverse
weather areas early. The equipment also enables the pilot to avoid
these areas or take other action necessary for safety of flight.
Therefore, the FAA proposes in Sec.  194.302(uu) that Sec.
91.1045(b)(5) apply to powered-lift. As an additional note, the
requirements of Sec. Sec.  135.173 and 135.175 apply as-written to
powered-lift because they apply to aircraft and the FAA is not
proposing to apply the helicopter provisions of those sections to
powered-lift.
    The provisions in Sec.  91.1109, with the exception of Sec.
91.1109(b)(4), are applicable to powered-lift because they apply to
aircraft. Section 91.1109(b) requires each person desiring to establish
or change an approved inspection program under this section to submit
the inspection program for approval to the Flight Standards office that
issued the program manager's management specifications. Under Sec.
91.1109(b)(4), the inspection program may be derived from an airplane
inspection program approved under Sec.  125.247 and currently in use
under part 125. The FAA has recently proposed to amend the
applicability of part 119 and allow powered-lift operations in part 125
in the Update to Air Carrier Definitions NPRM. However, the FAA is not
including part 125 in this SFAR because there are no powered-lift
currently in the certification process (or expected in the foreseeable
future) that meet the applicability requirements of part 125. Although
Sec.  91.1109(b)(4) is not applicable to powered-lift, the remaining
provisions in Sec.  91.1109 apply to powered-lift because they apply to
all aircraft.
    Additionally, the FAA noted that Sec.  91.1115(b)(1) uses the word
``airplane'' and the rest of paragraph (b) uses the word aircraft. In
examining the NPRM and the final rule promulgating subpart K, the FAA
expressed no intent to call out paragraph (b)(1) for airplanes only.
The NPRM and final rule expressed intent to hold operations under
subpart K to the same safety standards as other operations. Section
91.213, the other inoperative instruments and equipment regulation
within part 91, uses the word aircraft throughout and was the model
language used for Sec.  91.1115. The word airplane was substituted for
the word aircraft in Sec.  91.1115(b)(1) in error. The FAA proposes a
technical amendment to Sec.  91.1115(b)(1) to change the word
``airplane'' to ``aircraft.'' Changing this reference will not
adversely affect any other category of aircraft. As changed, this
section would then apply to powered-lift.
    The Continuous Airworthiness Maintenance Program (CAMP) program
manager is primarily responsible for maintaining the airworthiness of
the program aircraft, including airframes, aircraft engines,
propellers, rotors, appliances, and parts, including for powered-lift.
There are also other obligations, such as preparing mechanical
reliability reports and mechanical interruptions summaries. The CAMP
manager is also responsible for maintaining the operations manual and
maintaining the records required by Sec.  91.1427 for the specified
amount of time. Fractional ownership CAMP requirements apply to
powered-lift because, similar to the fractional ownership program
discussed above, the CAMP Manager's obligations are

applicable to all aircraft in the program, including powered-lift. As
discussed in section VII.A.2, the FAA reiterates that the term
``engine'' includes electric engines and any other powerplants.

C. Part 97 Rules for Powered-Lift

    Part 97 of title 14 prescribes standard instrument approach
procedures, obstacle departure procedures, and weather minimums that
apply to IFR takeoffs and landings at civil airports in the U.S.\377\
Section 97.3 defines Copter Procedures as helicopter procedures, with
applicable minimums as prescribed in Sec.  97.35.\378\ The definition
is limited to helicopters because when part 97 was promulgated, the FAA
did not envision that aircraft would have hybrid airplane and
helicopter characteristics. Consequently, powered-lift are currently
excluded from using Copter Procedures even if they are able to perform
the operations safely. The purpose of this section of the SFAR is to
propose a regulatory pathway that allows powered-lift to utilize the
Copter Procedures specified in Sec.  97.3.
---------------------------------------------------------------------------

    \377\ Instrument means a device using an internal mechanism to
show visually or aurally the attitude, altitude, or operation of an
aircraft or aircraft part. It includes electronic devices for
automatically controlling an aircraft in flight. See, 14 CFR 1.1.
The IFR are applicable to an aircraft, pilot, and operation when
operating in IMC as opposed to VMC.
    \378\ The minimums prescribed in Sec. Sec.  97.21 through 97.37,
including Sec.  97.35, are not published in the Code of Federal
Regulations. Federal Register citations affecting these procedures
can be found in the List of CFR Sections Affected (LSA), April 2020
at https://www.govinfo.gov/content/pkg/LSA-2020-04/html/LSA-2020-04-title14.htm. Section 97.20 prescribes the Standard for Terminal
Instrument Procedures (TERPs), which is documented on FAA Forms
8260-3, 8260-4, 8260-5, and 8260-15A, and depicted on aeronautical
charts published by the FAA at https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/. They are incorporated by
reference pursuant to 5 U.S.C. 552(a) and 1 CFR part 51.
---------------------------------------------------------------------------

    Part 97 was established because the FAA recognized the
technological advances that supported the ability to take-off and land
safely at airports while operating under IFR. It was originally
codified in 1963 without reference to Copter Procedures, but the term
was added in 1972 \379\ and defined as: helicopter procedures, with
applicable minimums as prescribed in Sec.  97.35. Helicopters may also
use other procedures prescribed in Subchapter C of this part and may
use the Category A minimum descent altitude (MDA), or decision height
(DH). The required visibility minimum may be reduced to one-half the
published visibility minimum for Category A aircraft, but in no case
may it be reduced to less than one-quarter mile or 1,200 feet runway
visual range (RVR). HAL means height above a designated helicopter
landing area used for helicopter instrument approach procedures. Point
in space means a helicopter instrument approach procedure to a point in
space to a missed approach point that is more than 2,600 feet from an
associated helicopter landing area.\380\
---------------------------------------------------------------------------

    \379\ General Operating and Flight Rules, 37 FR 6286 (Mar. 28,
1972).
    \380\ Designation of Federal Airways, Controlled Airspace and
Reporting Points, 37 FR 6286 (Mar. 28, 1972).
---------------------------------------------------------------------------

    Part 97 was further amended in 2002 to allow for technological
advances that support area navigation (RNAV), such as GPS, while
retaining the current ground-based systems.\381\ The amendments also
changed the Standard Instrument Approach Procedures name to Standard
Instrument Procedures to reflect that part 97 refers to both takeoffs
and approaches, and incorporated the term helipoint, defining it as the
aiming point for the final approach course for heliports. Later
amendments clarified terminology and updated certain terms for ICAO
consistency.
---------------------------------------------------------------------------

    \381\ Area Navigation (RNAV) and Miscellaneous Amendments, 72FR
31661 (Jun. 7, 2007).
---------------------------------------------------------------------------

    The FAA proposes in Sec.  194.305 that powered-lift operators
seeking to use Copter Procedures must use a powered-lift that has a
standard airworthiness certificate for IFR operations and meet
equivalent system design and stability as helicopters currently type
certificated for instrument flight under the airworthiness standards in
appendix B to parts 27 and 29. If a powered-lift does not meet that
equivalency, it would contain a limitation in its aircraft flight
manual prohibiting use of copter procedures. The specific airworthiness
standards will be established during the type certification process.
The criteria the FAA considers necessary for powered-lift to conduct
Copter Procedures under part 97 are explained below.
1. Copter Instrument Procedures
    Copter instrument procedures (IP) provide an instrument procedure
along a predetermined course to safely allow helicopter traffic to
transition between VFR and IFR for approaches and departures. The
criteria for these approaches or departures are defined in the FAA
Orders Standard for Terminal Instrument Procedures (TERPS) Manuals and
presume a certain level of vehicle performance and stability. For
example, copter instrument approach procedures (IAPs) are designed
presuming nominal descent rates and gradients over a range of given
airspeeds. Those approaches also presume the maximum and minimum
descent glideslope and gradient that may be encountered while
maintaining vertical navigation accuracy. In addition, the design of
the IAPs allow for the aircraft to descend to the minimum descent
altitude (MDA) or decision altitude (DA) prior to or upon arriving at
the missed approach point (MAP). At the MAP, the pilot must assess
whether the flight can safely and legally proceed to the destination in
the meteorological conditions present. Continuation of the flight
beyond the MAP must be accomplished via a visual transition segment in
accordance with the design of the IAP. The MAP is located such that the
aircraft can execute the missed approach procedure or visually
transition to a safe landing by using a nominal deceleration rate. Both
the missed approach procedures and departure procedures are designed
with the underlying minimum assumption of aircraft performance as
defined in the TERPS manual.
    Powered-lift IFR certification and compatibility with instrument
approaches will be assessed during the aircraft type certification
process. The aircraft's ability to conduct these types of operations
will be contained in the approved aircraft flight manual as part of the
operation limitations and the types of operation in accordance with
Sec. Sec.  23.2620, 25.1583, 27.1583, and 29.1583, 14 CFR part 27 or
29, appendix B, section IX, or airworthiness criteria developed in
accordance with Sec.  21.17(b) that establish an equivalent level of
safety.
2. Airworthiness Evaluation of Eligibility for Copter Procedures
    For powered-lift seeking approval to fly IFR and to use Copter
Procedures, the FAA will assess the aircraft's stability, system, and
equipage for IFR operations as compared to helicopters. This assessment
will occur during the type certification process. A powered-lift design
that meets standards that provide an equivalent level of safety to the
relevant standards in parts 27 and 29 can be certificated for IFR
flight and authorized to execute Copter Procedures. A powered-lift that
does not possess these characteristics may still be certificated for
IFR but will be prohibited from performing Copter Procedures and have a
limitation in the Aircraft Flight Manual to that effect.
    For helicopters, appendix B to parts 27 and 29 (``Airworthiness
Criteria for Helicopter Instrument Flight'') is based on the
traditional operating profile of a classically designed helicopter and
flight control system. The safety objectives contained within appendix
B for IFR approval focus on an increase in

stability, system design, and system safety over a part 27 or 29
Helicopter only approved to operate under VFR. The FAA does acknowledge
that for powered-lift, the appendix B assumptions are not directly
compatible due to the aircraft's hybrid capability and flight controls.
For powered-lift, safety objectives equivalent to appendix B will be
incorporated as part of the type design requirements, specifically
focusing on (1) adequate static stability, (2) adequate dynamic
stability, and (3) system safety.
    Static stability is the aircraft's ability to maintain or return to
its original flight path, and dynamic stability is the aircraft's
ability to return to a stabilized condition after being disturbed. The
ability to maintain uniform flight conditions and recover from
disturbances without requiring exceptional pilot skill and ability is
critical when assessing an aircraft for IFR approval. System safety is
a design process that ensures adequate robustness of the aircraft
systems based on the failure hazard analysis developed during the type
certification process. It involves identifying risks to the entire
system and developing mitigations based on how the aircraft responds to
system failures. Under the FAA's proposal, powered-lift designs may
include additional design redundancy compared to a classically designed
helicopter to ensure that the crew could safely manage any failures.
    The FAA proposes that powered-lift seeking approval for IFR
operations meet equivalent standards in appendix B regarding system
safety and stability during the type certification process. The
specific requirements will be established during the type certification
process when the FAA evaluates the types of operations that the
applicant intends to conduct. The FAA will assess those operations,
which may include IFR and Copter Procedures, as part of the type design
approval process to ensure that they can be conducted safely. Those
operations will be identified in the limitations of the aircraft flight
manual along with any other specific limitations and procedures
necessary for safe operation.
    Upon termination of the SFAR and in accordance with any changes
made permanent after the expiration of the SFAR, the FAA expects to
update guidance material, such as the TERPS Manual, certain Advisory
Circulars,\382\ the Airman Information Manual (AIM), and the
Aeronautical Information Publication (AIP).
---------------------------------------------------------------------------

    \382\ E.g., AC 90-80C Approval of Offshore Standard Approach
Procedures, Airborne Radar Approaches, and Helicopter En Route
Descent Areas; AC 90-101A--Approval Guidance for Required Navigation
Performance (RNP) Procedures with Authorization Required (AR); AC
90-105A--Approval Guidance for RNP Operations and Barometric
Vertical Navigation in the U.S. National Airspace System and in
Oceanic and Remote Continental Airspace; and AC 90-119 Performance
Based Navigation Operations.
---------------------------------------------------------------------------

    Navigation Specification (NavSpec) RNP 0.3 currently applies only
to rotorcraft operations. The FAA will assess the navigational system
for powered-lift to determine if they will be allowed to use this
NavSpec. The NavSpec will be amended as required following these
determinations.

D. Part 135 Rules for Powered-Lift

    The FAA expects there will be a demand to use powered-lift in
commercial operations requiring a part 119 certificate. Therefore, to
safely integrate these aircraft into part 135 operations, the FAA
completed a review of the current part 135 regulations to determine any
necessary additional applicability to powered-lift.
    Part 135 applies to two kinds of operations: on-demand and
commuter. These operations are defined in Sec.  110.2. On-demand
operations are those either conducted as a public charter under part
380 or any operations in which the departure time and location and
arrival location are specifically negotiated with the customer and are:
in rotorcraft; common carriage operations with airplanes (including
turbojet-powered airplanes) that have a passenger-seat configuration of
30 seats or fewer and a payload capacity of 7,500 pounds or less; or
noncommon or private carriage operations conducted with airplanes
having a passenger-seat configuration of less than 20 seats and a
payload capacity of less than 6,000 pounds.
    On-demand operations also include scheduled passenger-carrying
operations that consist of less than five round-trips per week on at
least one route between two or more points according to its published
flight schedules in airplanes (other than turbojet-powered airplanes)
that have a maximum passenger-seat configuration of 9 seats or less and
a maximum payload capacity of 7,500 pounds or less, or in any
rotorcraft. Finally, on-demand operations also include all-cargo
operations conducted with airplanes having a payload capacity of 7,500
pounds or less, or with rotorcraft.
    Commuter operations are scheduled operations conducted by any
person operating airplanes (other than turbojet-powered airplanes) that
have a maximum passenger-seat configuration of 9 seats or less and a
maximum payload capacity of 7,500 pounds or less, as well as all
rotorcraft, when such operations conduct at least five round trips per
week on at least one route between two or more points according to its
published flight schedules. As described in Section III. of this
preamble, the Update to Air Carrier Definitions NPRM proposes to revise
the definitions of commuter and on-demand to add powered-lift to part
110 so that operations can be conducted with those aircraft under part
135.
    Part 135 includes references to airplanes, helicopters, rotorcraft,
and powered-lift; however, part 135 only references powered-lift once.
That reference is in the flight experience requirements of Sec.  135.4.
Although the term powered-lift was introduced when Sec.  135.4 was
added to part 135, it was not necessary to review and revise any other
sections of part 135 to incorporate powered-lift because powered-lift
were not available for civil operations at that time.
    As previously stated in section VI.A, all regulatory requirements
imposed on ``aircraft'' apply to powered-lift. Accordingly, any
portions of part 135 which are silent to aircraft category are
applicable to all part 135 operations conducted with powered-lift. Part
135 training and qualification requirements for pilots of powered-lift
are discussed in section V.G of this preamble.
1. Part 135 Helicopter Rules Addressed in this SFAR
    The FAA analyzed the part 135 regulations and identified helicopter
rules that it determined should apply to powered-lift, either because
the rules are more conservative or appropriate considering the VTOL
capabilities of powered-lift. The FAA considered the similarities
between helicopter and powered-lift in areas such as performance
characteristics, vertical take-off and landing capabilities,
maneuverability, range and operating environment. The FAA also
considered those part 135 operations for which powered-lift could be
used in lieu of a helicopter due to the capabilities of powered-lift
such as those pertaining to air ambulance operations and off-shore
passenger carrying operations that are currently unique to helicopters.
i. Subpart B: Flight Operations
    Section 135.117(a) requires each PIC of an aircraft carrying
passengers to ensure that passengers have been orally briefed on
certain specific items. Specifically, Sec.  135.117(a)(6) requires
that, for flights involving extended overwater operations, passengers
must be orally briefed on ditching procedures and the use of required
flotation

equipment. An extended over water operation means, with respect to
helicopters, an operation over water at a horizontal distance of more
than 50 nautical miles from the nearest shoreline and more than 50
nautical miles from an off-shore heliport structure.\383\ In addition,
Sec.  135.117(a)(9) requires that, before each takeoff, the PIC of a
rotorcraft that involves flight beyond the autorotational distance from
the shoreline ensure that all passengers have been orally briefed on
the use of life preservers, ditching procedures, and emergency exit
from the rotorcraft in the event of a ditching. This briefing must
include the location and use of life rafts and other life preserver
devices as applicable.\384\
---------------------------------------------------------------------------

    \383\ 14 CFR 1.1.
    \384\ ``As applicable'' means if the aircraft is carrying rafts
or other life preserver devices onboard, passengers must be briefed
on the location and use of these items.
---------------------------------------------------------------------------

    In the preamble promulgating Sec.  135.117, the FAA explained that
the safety equipment requirements for helicopters are different from
those of airplanes.\385\ This differentiation is made for two reasons.
First, helicopters generally operate at lower altitudes than
airplanes--usually below 10,000 feet. These lower altitudes reduce the
autorotational distance and less time is available to prepare for an
unplanned landing due to an unexpected event. Second, airplanes are
designed with certain features that can enable them to float for a
period of time after ditching such as doors above the waterline and, in
some airplanes with pressurized cabins, closeable outflow valve(s).
Helicopters do not incorporate these design features and may not be
able to float on the surface like an airplane after ditching.
Additionally, helicopters, by design, generally have a higher center of
gravity and, when ditched, can roll over and then rapidly fill with
water causing them to sink. Based on these two considerations,
helicopter passengers must have additional protections for survival in
water if they need to exit the helicopter after ditching as reflected
by the requirements in Sec.  135.117(a)(9).\386\
---------------------------------------------------------------------------

    \385\ Air Ambulance and Commercial Helicopter Operations, Part
91 Helicopter Operations, and Part 135 Aircraft Operations; Safety
Initiatives and Miscellaneous Amendments, 75 FR 62639 (Oct. 12,
2010).
    \386\ If the aircraft is carrying rafts or other life preserver
devices onboard, passengers must be briefed on the location and use
of these items.
---------------------------------------------------------------------------

    Powered-lift may have a wide variety of design features that may
influence buoyancy after ditching and the ability to evacuate in case
of an emergency. For example, some aircraft with pressurized cabins are
likely to be more buoyant and water resistant than other aircraft
without a pressurized cabin. In addition, different aircraft designs,
including a lower center of gravity and passenger doors above the
waterline, may increase the ability to not take on water and float for
a longer period of time. With regard to features that may influence
buoyancy and whether the powered-lift will take on water or float for a
longer period of time after ditching is unknown. The FAA does not have
the historical data on these new aircraft designs to assert that the
positive buoyancy characteristics and the potential to float for a
longer period of time--characteristics of airplane designs--will exist
in powered-lift. Therefore, the FAA proposes to address powered-lift as
helicopters for the purpose of over water operations.
    Further because some-powered lift may be capable of operations
beyond 50 NM of the shoreline or an off-shore heliport structure and
are able to conduct takeoff and landing operations similar to
helicopters, the FAA proposes to apply to powered-lift, the helicopter-
specific definition in Sec.  1.1 of extended over-water operations.
This means if a powered-lift conducts an operation beyond 50 NM of the
shoreline or an off-shore heliport structure, then it would be
conducting an extended overwater operation and would be required to
conduct the briefing required by Sec.  135.117(a)(6).
    Additionally, the FAA anticipates powered-lift may be designed to
auto-rotate or glide to a landing. Accordingly, the FAA proposes in
Sec.  194.308(b) to apply the briefing requirement of Sec.
135.117(a)(9) to powered-lift that are conducting operations beyond the
auto-rotational distance or gliding distance from the shoreline. This
will ensure the use of life preservers, ditching procedures and
emergency exits, and if applicable, the location and use of life rafts
and other life preserver devices have been briefed if a powered-lift
ditches.
ii. Subpart C: Aircraft and Equipment
    Section 135.160 requires radio altimeters for all rotorcraft
operations conducted under part 135. The FAA determined that radio
altimeters are an important safety device designed to inform the pilot
of the aircraft's actual height above the surface.\387\ Radio
altimeters are valuable safety tools. For example, they provide
additional situational awareness during an inadvertent encounter with
IMC as well as additional situational awareness after encounters with
brownout,\388\ whiteout,\389\ or other situations where vision is
suddenly limited, and pilots lose their reference to the horizon and
the ground. Additionally, radio altimeters can greatly improve a
pilot's awareness of height above the ground during hover, landing in
unimproved landing zones, and landings in confined areas where a more
vertical approach may be required.\390\
---------------------------------------------------------------------------

    \387\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, 79 FR 9938 (Feb. 21, 2014).
    \388\ The Aeronautical Information Manual describes brownout as
an in-flight visibility restriction due to dust or sand in the air.
In a brownout, the pilot cannot see nearby objects which provide the
outside visual references necessary to control the aircraft near the
ground.
    \389\ The Aeronautical Information Manual describes white out as
occurring when a person becomes engulfed in a uniformly white glow.
The glow is a result of being surrounded by blowing snow, dust,
sand, mud or water.
    \390\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, 79 FR 9931 (Feb. 21, 2014).
---------------------------------------------------------------------------

    The FAA foresees powered-lift being utilized in similar operational
locations to rotorcraft, such as takeoff and landing operations to and
from unimproved landing zones, including off-airport operations. This
means that these aircraft could encounter many of the same hazardous
issues, such as flat light,\391\ whiteout, and brownout, which
helicopters conducting part 135 operations can encounter. In addition,
during inadvertent encounters with IMC, a radio altimeter can also
provide additional situational awareness to the pilot. In order to
establish a level of safety comparable to current rotorcraft operations
under part 135, the FAA proposes in Sec.  194.308(c) to require persons
operating powered-lift to comply with the radio altimeter requirements
of Sec.  135.160.\392\ As permitted for rotorcraft that must comply
with Sec.  135.160(a), the FAA also proposes to allow persons operating
powered-lift with a maximum takeoff weight no greater than 2,950
pounds, the ability to apply for a deviation from the radio altimeter
requirements in accordance with Sec.  135.160(b).
---------------------------------------------------------------------------

    \391\ The Aeronautical Information Manual describes Flat Light
as an optical illusion that causes pilots to lose their depth of
field and contrast in vision.
    \392\ A-02-35 NTSB recommendation to incorporate radio
altimeters for passenger carrying operations.
---------------------------------------------------------------------------

    Section 135.163 outlines the equipment requirements for all
aircraft carrying passengers under IFR. The intent of Sec.  135.163(g)
is to ensure an adequate level of safety for multi-engine aircraft
carrying passengers under IFR in the event that an engine fails
resulting in an accompanying loss of electrical generation on that
engine. By requiring the second power source to be on a

separate engine, an engine failure during IMC does not become a
compound emergency of engine failure and electrical failure
simultaneously. Section 135.163(g) contains an exception for multi-
engine helicopters that states the two required generators may be
mounted on the main rotor drive train and a loss of one powerplant will
not affect both generators since they are on a common drive train.
Section 135.163 currently applies to powered-lift as written. The FAA
proposes in Sec.  194.308(d) to allow powered-lift to utilize the
exception for helicopters contained in Sec.  135.163(g) when that
powered-lift is equipped with a rotor system drivetrain that is driven
by two separate powerplants and able to run the two required generators
because, just as for rotorcraft, the loss of one powerplant would not
affect both generators.
    Part 135 contains requirements for emergency equipment for both
extended overwater and rotorcraft overwater operations. Specifically,
Sec.  135.167 details the requirements for all aircraft conducting
extended overwater operations, and Sec.  135.168 details the
requirements for rotorcraft overwater operations. Section 135.167
requires life preservers be easily accessible to each seated occupant
in an aircraft, subject to a limited exception during an air ambulance
operation. Section 135.168 requires life preservers be worn by
occupants in rotorcraft in overwater operations. In Sec.  135.167, an
emergency locator transmitter (ELT) must be attached to a required life
raft, while Sec.  135.168 requires the aircraft to carry an approved
and installed ELT because there is no requirement to carry a life raft.
    Airplanes are designed with certain features that enable them to
float for a period of time after ditching, such as doors above the
waterline, partially empty fuel tanks, and in some airplanes,
pressurized cabins with closeable outflow valves. Due to powered-lift
being a new entrant into the civilian marketplace, the FAA does not
have the historical data to assert that these positive buoyancy
characteristics of airplanes will exist in powered-lift. Accordingly,
the FAA proposes to apply Sec.  194.308(e) to Sec.  135.168 (that
pertains to rotorcraft) to powered-lift. If the powered-lift is
operating overwater beyond the gliding or autorotational distance of
the shoreline then life preservers must be provided and worn by each
occupant.
    In developing this proposal, the FAA considered the 2010 notice of
proposed rulemaking (NPRM),\393\ which proposed the requirement for
helicopters operated beyond the autorotational distance from shore to
be equipped with electronically deployable or externally mounted life
rafts. In the 2014 final rule,\394\ the FAA removed that proposed life
raft requirement, reasoning that the cost of equipping helicopters with
life rafts would not be justified by an increase in the survivability
of accidents. The FAA stated that there are relatively few accidents
beyond autorotational distance from the shoreline. Among the accidents
identified, few qualify as survivable, and of the survivable accidents,
the requirement to wear life preservers would generate the greatest
likelihood of surviving in the water.\395\
---------------------------------------------------------------------------

    \393\ Air Ambulance and Commercial Helicopter Operations, Part
91 Helicopter Operations, and Part 135 Aircraft Operations; Safety
Initiatives and Miscellaneous Amendments, 75 FR 62639 (Oct. 12,
2010).
    \394\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, 79 FR 9931 (Feb. 21, 2014).
    \395\ Id. at 9973.
---------------------------------------------------------------------------

    The FAA anticipates powered-lift operated overwater will have a
survivability sequence (sequence of events which occur upon impact with
the water) more similar to rotorcraft than airplanes and that the
donning of life preservers would provide for the greatest likelihood of
surviving in the water versus requiring the carriage of a life raft
whenever powered-lift are conducting overwater operations beyond
gliding and/or autorotational distance from the shoreline.
Additionally, the ELT requirements of Sec.  135.168 are appropriate for
powered-lift because there is no life raft requirement except during
extended overwater operations. This will ensure that all powered-lift
that conduct operations beyond the gliding distance or the
autorotational distance from the shoreline will have the added safety
benefit of rescue locating by the signaling device.
    Section 135.181 details performance requirements for all aircraft
operated over-the-top \396\ or in IFR conditions. This section also
contains a provision, in Sec.  135.181(b), that is specific to
multiengine helicopters carrying passengers in the offshore environment
and that allows these helicopters to conduct certain operations over-
the-top or in IFR conditions. The FAA asserted that the provision
contained in Sec.  135.181(b) was in the public interest to allow this
specific performance requirement for multiengine helicopters conducting
passenger carrying operations offshore as such operations support
exploration and development of energy supplies, and provided economic
relief to those operators by allowing better utilization of the
existing fleet without compromising safety.\397\ The FAA anticipates
that powered-lift could also be used in conducting offshore passenger
operations that are currently provided by multiengine helicopters. The
FAA notes that all powered-lift with the possibility of being operated
in civil operations will be multi-engine; accordingly, the FAA proposes
in Sec.  194.308(f) to apply Sec.  135.181(b) to all powered-lift. The
FAA anticipates a powered-lift that is able to meet the performance
requirements of Sec.  135.181(b) would be providing the same level of
safety established for helicopters using the same rationale that
helicopters were afforded with this exception when operating in the
offshore environment. This exception would provide the same economic
relief to powered-lift operators as that experienced by helicopter
operators.
---------------------------------------------------------------------------

    \396\ Over-the-top means above the layer of clouds or other
obscuring phenomena forming the ceiling.
    \397\ Rotorcraft Regulatory Review Program Notice No. 5, 50 FR
10165 (Mar. 13, 1985).
---------------------------------------------------------------------------

    Section 135.183 provides the performance requirements for land
aircraft to operate over water. The basic premise for this regulation
is that a land aircraft must be operated in such a way as to keep the
aircraft out of the water. Paragraph (a) requires that any aircraft
operate at an altitude that allows it to reach land in the event of an
engine failure. Paragraph (b) allows overwater operations strictly
limited to only takeoff and landing operations. Paragraph (c) requires
a multiengine aircraft to be able to climb with its critical engine
inoperative at least 50 feet a minute at 1000 feet above the surface.
Paragraph (d) allows helicopters the option of installing floats if
they are unable to meet the requirements of paragraph (a) or (c). With
the exception of paragraph (d), powered-lift operations over water must
comply with the provisions of Sec.  135.183, because it references
aircraft. In 1973, the FAA added paragraph (d) for helicopters equipped
with flotation devices.\398\ The FAA determined that helicopters could
be operated safely beyond land in the case of an engine failure as long
as the helicopter was equipped with flotation devices, even if they did
not meet the requirements in paragraph (a) or (c).\399\ The FAA
anticipates that powered-lift may be utilized in the same fashion as
helicopters carrying passengers over

water. The FAA is uncertain if powered-lift will be equipped with
floats; however, the FAA expects that a powered-lift that is equipped
with floatation devices through an FAA certification process will
provide the same level of safety that is currently extended to
helicopters because the FAA anticipates that a powered-lift with floats
would land similarly to a float-equipped helicopter. Accordingly, the
FAA proposes in Sec.  194.308(g) to allow powered-lift to utilize the
exception contained in paragraph (d) if the powered-lift is unable to
meet the requirements of paragraph (a) or (c).
---------------------------------------------------------------------------

    \398\ Helicopter Use Over Water, 38 FR 12906 (May 17, 1973)
(amending Sec.  135.147, which contained the requirements in Sec.
135.183 prior to the recodification in 1978).
    \399\ Id.
---------------------------------------------------------------------------

iii. Subpart D: VFR/IFR Operating Limitations and Weather Requirements
    Section 135.207, which outlines helicopter surface reference
requirements under VFR, was originally promulgated in 1958 and at a
time when helicopters were not widely equipped with gyroscopic flight
instruments.\400\ This rule has remained unchanged throughout the years
leaving its application, in this case, to be somewhat inappropriate due
to the advances in technology of many aircraft since its inception.
Much research has also occurred in the science of human factors
associated with flying at night in reference to objects on the surface
or on the horizon. This section specifically omitted airplanes at the
time of publication because airplanes were more widely equipped with
the adequate instrumentation needed to maintain a pilot's situational
awareness.\401\ The FAA anticipates that powered-lift will be equipped
with advanced technologies and flight instrumentation that would
provide adequate situational awareness as well as an ability to
maintain positive control of an aircraft in lower light and visibility
situations. However, some powered-lift could be manufactured without
gyroscopic flight instruments. To ensure the pilot can safely control
the aircraft, the FAA proposes in Sec.  194.308(h) that this section
only apply to powered-lift that do not have the flight instrumentation
listed in Sec.  135.159 installed and operable.
---------------------------------------------------------------------------

    \400\ Part 46--Scheduled Air Carrier Helicopter Certification
and Operation Rules, 23 FR 2265 (Apr. 8, 1958).
    \401\ Part 46--Scheduled Air Carrier Helicopter Certification
and Operation Rules, 23 FR 2264 (Apr. 8, 1958).
---------------------------------------------------------------------------

    Section 135.227(d) prohibits helicopters from flying under IFR into
known or forecast icing conditions or under VFR into known icing
conditions unless the helicopter is type certificated and appropriately
equipped for operations in icing conditions. A powered-lift should also
be prohibited from operating in certain icing conditions unless it is
type certificated and appropriately equipped for operations in such
conditions. This requirement will ensure those aircraft can safely
operate in icing conditions because they are appropriately certificated
and equipped with the proper equipment. Section 135.227(c)(2) and (3),
which are applicable to airplanes, are similar to Sec.  135.227(d) in
that those provisions require the aircraft to meet certain
airworthiness standards in order to operate in certain icing
conditions. However, Sec.  135.227(d) is appropriate to apply to
powered-lift because the airworthiness requirements are less specific,
which makes this paragraph more suited to the Sec.  21.17(b)
certification process that powered-lift comply with, which is
appropriate as the FAA gathers more information about powered-lift
operations in icing conditions. Therefore, the FAA proposes in Sec.
194.308(i) to apply Sec.  135.227(d) to powered-lift that are type
certificated and appropriately equipped for operations in icing
conditions. Operations in icing conditions are discussed more
extensively in VI.D.2.v regarding airplane rules and weather
requirements.
    Section 135.229 provides the airport requirements that apply to all
aircraft with the exception of paragraph (b)(2)(ii) in which
helicopters are also allowed to use reflective material.\402\ The
landing lights on helicopters are generally oriented so that they shine
at an angle approximate to a normal approach angle used by helicopters.
This negates the need for the landing area to be lit up with runway
lights and permits the helicopter pilot to easily pick out and maintain
a safe approach angle to an area marked by reflective material. The FAA
expects that, since powered-lift are capable of a vertical takeoff or
landing, they could be equipped with landing lights oriented in a
direction that enables the pilot to see a landing area marked by
reflective material. Accordingly, the FAA determined that for powered-
lift that are conducting a vertical takeoff or landing and that are
equipped with landing lights oriented in a direction that enables the
pilot to see the takeoff or landing area marked by reflective material,
then powered-lift may use that reflective material that a helicopter is
permitted by Sec.  135.229(b)(2)(ii). If conducting a takeoff or
landing roll using wing-born lift, a powered-lift must takeoff or land
at an airport with boundary or runway marker lights, as set forth in
Sec.  135.229(b)(2)(i). The FAA proposes in Sec.  194.308(j) to allow
powered-lift to takeoff from or land at an airport that uses reflective
material when conducting a takeoff or landing in the vertical-lift
flight mode and is equipped with landing lights oriented in a direction
that enables the pilot to see the takeoff or landing area marked by
reflective material.
---------------------------------------------------------------------------

    \402\ Miscellaneous Amendments, 29 FR 2988 (Mar. 5, 1964).
---------------------------------------------------------------------------

iv. Subpart F: Crewmember Flight Time and Duty Period Limitations and
Rest Requirements
    Subpart F details crewmember flight time, duty period limitations,
and rest requirements. These sections are applicable to scheduled and
unscheduled operations regardless of the type of aircraft with the
exception of Sec.  135.271, Helicopter Hospital Emergency Medical
Evacuation Services (HEMES). The FAA has noted previously that it uses
the terms helicopter air ambulance (HAA) and HEMES
interchangeably.\403\ Section 135.271 requires different rest and duty
requirements for HAA operations conducted from a hospital, and in order
to assure that a helicopter pilot is adequately rested, there is a
requirement to have an approved place of rest at or in close proximity
to the hospital where the helicopter is based. The FAA stated in the
NPRM for Sec.  135.271 that air ambulance operations are of undoubted
social benefit and proven safety, and that the FAA has been issuing
exemptions for these operations for several years and is satisfied that
they are safe.\404\
---------------------------------------------------------------------------

    \403\ National Policy regarding Helicopter Air Ambulance
Operations, available at https://www.faa.gov/documentLibrary/media/Notice/N_8900.509.pdf.
    \404\ Flight Time Limitations and Rest Requirements for Flight
Crewmembers, 49 FR 12136, 12141 (Mar. 28, 1984).
---------------------------------------------------------------------------

    Since powered-lift are able to conduct vertical takeoffs and
landings, they could be based at a hospital heliport. Therefore, the
FAA anticipates powered-lift operators will be able to conduct HAA
operations that are subject to the requirements of Sec.  135.271.
Operators that have a powered-lift based at a hospital should be
allowed to use the rest and duty rules permitted by this section, just
as current helicopter operators are permitted. The FAA applies this
provision to all HAA instead of using the term HEMES for maximum
clarity going forward with respect to which operations these
limitations are applicable to. This determination is consistent with
the preamble accompanying

implementation of this provision, which indicates it was intended to
apply to all HAA.\405\ Therefore, the FAA proposes in Sec.  194.308(k)
that Sec.  135.271 apply to powered-lift conducting HAA operations in
accordance with subpart L of part 135.
---------------------------------------------------------------------------

    \405\ See, e.g., Helicopter Air AMBULANCE, commercial
Helicopter, and Part 91 Helicopter Operations, 79 FR 9944 (Feb. 21,
2014), which states: ``As established by this rule, all helicopter
air ambulance operations with medical personnel or patients on board
must be conducted under part 135. The provisions of Sec. Sec.
135.267 and 135.271 would therefore apply to the helicopter air
ambulance operations previously conducted under part 91''.
---------------------------------------------------------------------------

v. Subpart J: Maintenance, Preventative Maintenance, and Alterations
    Section 135.429 applies to all aircraft, except for paragraph (d)
which states that the FAA may approve procedures for the performance of
required inspection items by a pilot of a rotorcraft that operates in
remote areas or sites. The pilot may perform the inspection items, with
certain limitations, when no other qualified personnel are available
and a mechanical interruption occurs. The FAA expects a pilot who is
trained under the requirements of Sec.  135.429(d) would provide the
same level of competency as a certificated mechanic.\406\ The rule is
intended to allow a certificate holder the opportunity to establish a
preventive maintenance process for when a mechanical interruption
occurs in a remote area or site. The inspection must be accomplished
under the direct control of the certificate holder's maintenance
program. Because powered-lift may take off and land like a rotorcraft,
some powered-lift may operate in remote areas or sites. Consequently
powered-lift used in such operations experience the same challenges
that exist for rotorcraft when an unscheduled mechanical interruption
occurs. Therefore, the FAA proposes in Sec.  194.308(l) to apply Sec.
135.429(d) to powered-lift that operate in remote areas or sites.
---------------------------------------------------------------------------

    \406\ See Rotorcraft Regulatory Review Program Amendment No. 5;
Operations and Maintenance; Final Rule, 51 FR 40692 (Nov. 7, 1986).
---------------------------------------------------------------------------

vi. Subpart L: Helicopter Air Ambulance Equipment, Operations, and
Training Requirements
    Helicopter air ambulance operations must comply with subpart L of
part 135 in addition to other requirements of this part. Since subpart
L became effective, significant decreases in HAA fatalities have
occurred, further justifying the positive impact on the safety benefit
of these requirements. Since powered-lift can operate similar to a
helicopter during the critical phases of flight of takeoff and landing,
and to ensure the higher level of safety that is afforded to medical
personnel aboard those aircraft, the FAA proposes powered-lift
conducting air ambulance operations will be required to comply with
subpart L. Moreover, Sec.  135.1 outlines the applicability of part
135, and Sec.  135.1(a)(9) lists HAA operations as defined in Sec.
135.601(b)(1). Because the FAA proposes that subpart L apply to
powered-lift, it also proposes in Sec.  194.308(a) that Sec.
135.1(a)(9) apply to powered-lift conducting air ambulance operations.
    The FAA anticipates that operators utilizing powered-lift for air
ambulance activities will present a new dynamic because these aircraft
can be operated like an airplane and a helicopter. The FAA currently
differentiates between airplane air ambulance operations and HAA
operations including the required equipment, weather minimums, required
risk analysis, flight monitoring, and the authorizing document issued
to the operator.\407\ As provided in the preamble to the final rule
implementing subpart L, helicopter air ambulance operations are
conducted under unique conditions.\408\ Such flights are often time
sensitive and operate at low altitudes and under varied weather
conditions. They must often land at unfamiliar, remote, or unimproved
sites with hazards like trees, buildings, towers, wires, and uneven
terrain. Patients being transported often do not have a choice between
operator or mode of transportation. For these reasons, the FAA
established more stringent safety regulations applicable to HAA
operations which include weather minimums and visibility requirements,
as well as mandating flight planning, preflight risk analyses, safety
briefings for medical personnel, and the establishment of operations
control centers (OCC) for certain operators to help with risk
management and flight monitoring. The rule also includes provisions to
encourage instrument flight rules (IFR) operations. It requires
helicopter air ambulances to be equipped with both helicopter terrain
awareness and warning systems (HTAWS) (the HTAWS will warn pilots about
obstacles in their flight path), and flight data monitoring systems.
Finally, helicopter air ambulance pilots are required to hold
instrument ratings.\409\
---------------------------------------------------------------------------

    \407\ Air ambulance operations conducted in an airplane are
approved through issuance of Operations Specification A024, while
air ambulance conducted in a helicopter are approved through
issuance of A021. When the type of operation is proposed in powered-
lift, the FAA will issue the appropriate operations specification.
    \408\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, 79 FR 9931 (Feb. 21, 2014).
    \409\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, 79 FR 9931 (Feb. 21, 2014).
---------------------------------------------------------------------------

    The FAA anticipates that powered-lift be used in air ambulance
operations would likely complete operations similar to those currently
conducted by helicopters and thus also be likely to encounter
circumstances similar to helicopters in air ambulance operations.
Powered-lift conducting air ambulance operations should be afforded the
same level of safety as HAA operations, and the rules contained in
subpart L will provide this level of safety. Accordingly, the FAA
proposes in Sec.  194.308(m) that the applicability and definitions
section of subpart L also apply to powered-lift.
    The FAA conducted an analysis of the sections in subpart L versus
those contained throughout subparts A through J to determine if any
changes in subpart L were required for continuity with the proposed
powered-lift SFAR, and to ensure there was no conflict in applying
these rules when air ambulance operations are conducted in a powered-
lift. This analysis and applicability of subpart L are described in the
following paragraphs.
    Section 135.154 requires terrain awareness and warning systems
(TAWS) in airplanes with a passenger seat configuration of 6 to 9
passengers, while Sec.  135.605 requires helicopter terrain awareness
and warning system (HTAWS) equipment for all helicopters used in HAA
operations, regardless of passenger seat configuration. This difference
in requirements is based upon the different flight characteristics and
the operating environment in which these aircraft operate, such as
speed, maneuverability, and the altitudes at which they normally
operate.
    As previously discussed, powered-lift are capable of flight similar
to both airplanes and helicopters. Consequently, individually the
current TAWS and HTAWS are not a complete solution for powered-lift due
to each equipment's capabilities and limitations. In the subsequent
preamble discussion regarding the applicability of TAWS to airplanes,
the FAA explains its determination that HTAWs or an FAA approved TAWS
A/HTAWS hybrid system rather than an airplane-specific TAWS, is
appropriate for powered-lift having a passenger seating configuration,
excluding any pilot seat, of 6 or more. See proposed Sec.  194.307(q).
Consistent with proposed Sec.  194.307(q), for powered-lift operating
under subpart

L, the FAA is proposing to allow a hybrid system in a powered-lift that
utilizes the features of a TAWS A system for wing-borne flight and
HTAWS for vertical flight modes of operation for compliance with Sec.
135.605. Without a TAWS A/HTAWS hybrid system, the FAA determined that
the current HTAWS specification would provide the best level of safety
without an undue number of nuisance warnings. The FAA proposes in Sec.
194.308(o) that any powered-lift that is used in air ambulance
operations as defined Sec.  135.601, modified by the proposed SFAR, be
equipped with HTAWS, unless equipped with an FAA approved TAWS A/HTAWS
hybrid system, in accordance with Sec.  135.605.
    Section 135.603 requires the PIC of a helicopter air ambulance
operation to meet the requirements of Sec.  135.243 and to hold either
a helicopter instrument rating or an ATP certificate with a category
and class rating for that aircraft, not limited to VFR. It is equally
important for PICs of powered-lift air ambulance operations to meet the
requirements set forth in this section. In the NPRM implementing
updated requirements for helicopter air ambulance operations, the FAA
explained that inadvertent flight into IMC is a common factor in
helicopter air ambulance accidents. In general, many accidents result
when pilots who lack the necessary skills or equipment to fly in
marginal VMC or IMC attempt flight without outside references. The
proposal was intended to ensure that helicopter air ambulance pilots
are equipped to handle these situations and extract themselves from
these dangerous situations. A pilot who receives the more extensive
training on navigating a helicopter solely by reference to instruments
provided by obtaining an instrument rating is better able to maintain
situational awareness and maneuver the helicopter into a safe
environment than a pilot without an instrument rating.\410\
---------------------------------------------------------------------------

    \410\ Air Ambulance and Commercial Helicopter Operations, Part
91 Helicopter Operations, and Part 135 Aircraft Operations; Safety
Initiatives and Miscellaneous Amendments, 75 FR 62639 (October 12,
2010).
---------------------------------------------------------------------------

    These concerns regarding inadvertent flight into IMC would be
equally applicable for PICs of powered-lift. Accordingly, the FAA
proposes in Sec.  194.308(n) that these requirements also apply for
powered-lift operations occurring under subpart L. For further
discussion of proposed amendments to Sec.  135.243, please see section
I.5.i. of this preamble.
    The FAA also determined that it would be appropriate to apply the
requirement set forth in Sec.  135.607 for a helicopter to have for
flight data monitoring system capable of recording flight performance
data to powered-lift conducting air ambulance operations. The FAA has
not identified any reason to differentiate between helicopters and
powered-lift conducting air ambulance operations for purposes of
compliance with this requirement, as it would be equally important for
powered-lift to record flight performance data in the dynamic
environment contemplated by subpart L. Accordingly, the FAA proposes
this requirement be applicable to powered-lift in Sec.  194.308(p).
    Section 135.609(a) specifies the minimum ceiling and visibility
requirements for conducting VFR helicopter air ambulance operations in
Class G airspace. Those requirements are broken down into day or night,
mountainous or non-mountainous, and local or non-local flying areas.
Section 135.601(b)(3) defines mountainous areas as those designated
under part 95 of chapter I. Part 95 contains maps and the latitude and
longitude coordinates depicting the mountainous areas of the eastern
and western United States as well as Alaska, Hawaii, and Puerto Rico.
Section 135.601(b)(4) defines non-mountainous areas as areas other than
the mountainous areas listed in part 95. In addition, Sec.  135.609(b)
explains that a certificate holder may designate local flying areas in
a manner acceptable to the Administrator that must (1) not exceed 50 NM
in any direction from each designated location; (2) take into account
obstacles and terrain features that are easily identifiable by the
pilot in command (PIC) and from which the PIC may visually determine a
position; and (3) take into account the operating environment and
capabilities of the certificate holder's helicopters.
    The FAA established the minimums under Sec.  135.609(a), which are
more stringent than the VFR visibility requirements of Sec.  135.205
for helicopters, because the FAA believed that all flight operations
conducted under VFR in helicopter air ambulance operations should
comply with more stringent weather requirements. They also asserted
these ceiling and visibility requirements would be an effective method
of increasing safety in helicopter air ambulance operations.\411\ For
powered-lift, the FAA evaluated the VFR minimum altitudes, required
visibility, and distance from cloud requirements for airplanes as
contained in Sec. Sec.  135.203 (VFR minimum altitudes), 135.205 (VFR
visibility requirements), and 91.155 (distance from cloud requirements)
and applied these airplane minimums to the table contained in Sec.
135.609(a) which resulted in minimums that are most closely aligned
with the FAA's intent of applying the ceiling and visibility
requirements of airplanes to powered-lift.
---------------------------------------------------------------------------

    \411\ Air Ambulance and Commercial Helicopter Operations, Part
91 Helicopter Operations, and Part 135 Aircraft Operations; Safety
Initiatives and Miscellaneous Amendments, NPRM, 75 FR 62649 (Oct.
12, 2010).
---------------------------------------------------------------------------

    A powered-lift may takeoff and land vertically and can therefore
access the same locations that a HAA aircraft can, thus making it
suitable to conduct these kinds of operations; however, the powered-
lift can be much different than a helicopter in cruise flight, where
the powered-lift--during wing-born flight mode--is anticipated to
operate more like an airplane. These operating differences include
higher airspeeds, which require more distance to see and avoid
obstacles and terrain, and more airspace to conduct maneuvering. Speed
and maneuverability also play a role in the ability of a powered-lift
operating with a cloud layer to avoid objects, including other
aircraft, that come out of the clouds. Additionally, these
characteristics may limit the ability of a powered-lift to conduct an
emergency landing into the same areas a helicopter might use. This can
be predicated on the time it takes the powered-lift to transition to
VTOL or even its inability to use VTOL with certain failures, causing
it to operate more like an airplane in this respect.
    As a result of the foregoing, the FAA determined powered-lift
should be operated at a higher minimum when operating at night than
what is currently required under Sec.  135.609 for helicopters. The
proposed requirements for powered-lift are identical to the helicopter
requirements in the Sec.  135.609(a) table for daytime operations, but
the ceiling increases for nighttime operations to help create a safer
operating environment for powered-lift. Finally, the FAA notes that the
table in Sec.  135.609(a) contains two columns for night operations:
one column for ``night'' operations and another column for ``night
using an approved NVIS or HTAWS'' operations. Because HTAWS are now
required, the ``night'' column requirements are no longer relevant and
have been phased out. The FAA proposes in Sec.  194.308(q) that
powered-lift comply with the minimum ceiling and visibility
requirements for VFR air ambulance

operations in Class G airspace as described in the following table
(Table 10):

                        Table 10--Proposed VFR Air Ambulance Minimums in Class G Airspace
----------------------------------------------------------------------------------------------------------------
                                                                Day                            Night
                    Location                     ---------------------------------------------------------------
                                                      Ceiling       Visibility        Ceiling       Visibility
----------------------------------------------------------------------------------------------------------------
Non-mountainous Local Flying Areas..............          800 FT            2 SM        1,500 FT            3 SM
Non-mountainous Non-Local Flying Areas..........          800 FT            3 SM        1,500 FT            3 SM
Mountainous Local Flying Areas..................          800 FT            3 SM        2,500 FT            3 SM
Mountainous Non-Local Flying Areas..............        1,000 FT            3 SM        2,500 FT            5 SM
----------------------------------------------------------------------------------------------------------------

    In addition, the FAA proposes Sec.  135.609(b) apply to certificate
holders operating powered-lift in air ambulance operations so that they
may designate local flying areas that meet the requirements of
paragraphs (b)(1) through (3). Weather minimums are less stringent in
local flying areas because of pilots' increased familiarity with
obstacles and the operating environment.\412\ The FAA expects that
powered-lift pilots conducting air ambulance operations will have the
same familiarity with local obstacles and the operating environment.
---------------------------------------------------------------------------

    \412\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, 79 FR 9931 (Feb. 21, 2014).
---------------------------------------------------------------------------

    Section 135.611 sets forth requirements for HAA IFR operations at
locations without weather reporting. The FAA evaluated the provisions
of this section and determined that it would be appropriate to provide
the ability for authorization for IFR operations of powered-lift at
airports with an instrument approach procedure and where a weather
report is not available. This provision would only be able to be
utilized by powered-lift operating under subpart L that are certified
for IFR operations and that receive an additional authorization from
the Administrator. The FAA proposes the applicability of this section
in Sec.  194.308(r).
    Section 135.613 details the ceiling and visibility requirements for
approach and departure IFR transitions for HAA operations. This rule
was codified to establish weather minimums for HAA that are using an
instrument approach and are now transitioning to visual flight for
landing. It also permits VFR to IFR transitions for departures if the
pilot has filed an IFR flight plan and will obtain an IFR clearance
within 3 NM of the departure location and the pilot departs following
an FAA-approved obstacle departure procedure. This section is intended
to encourage IFR operations because of the safety benefits associated
with flights conducted under IFR. Section 135.613(a) establishes the
requirements when conducting an authorized instrument approach and
transitioning from IFR to VFR flight.
    Section 135.613(a)(1) requires a flight visibility of 1 statute
mile (SM) and a ceiling based upon the minimums published on the
approach chart. This is applicable for Point-in-Space (PinS) Copter
Instrument approaches that are annotated with a ``Proceed VFR''
segment, and the distance from the missed approach point to the landing
area is 1 NM or less. The FAA proposes in Sec.  194.308(s)(1) that
Sec.  135.613(a)(1) only apply to powered-lift that are equipped and
certified to conduct these PinS approaches.
    Section 135.613(a)(2) specifies the minimum ceiling and visibility
requirements for all instrument approaches if the missed approach point
to the landing area is 3 NM or less. These minimum ceiling and
visibility requirements are also applicable to PinS approaches which
contain a ``Proceed VFR'' segment where the missed approach point to
the landing area is greater than 1 NM but no greater than 3 NM. The FAA
noted in the Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations final rule that in most cases the rule permits
flight under less restrictive weather minimums than are currently
allowed for cruise flight in uncontrolled airspace.\413\ The ceiling
requirement of Sec.  135.613(a)(2) is less restrictive than that
required by Sec.  135.609(a), and the visibility requirement is
generally less restrictive than Sec.  135.609(a) as well. In the
Helicopter Air Ambulance final rule, when discussing permitting less
restrictive ceilings and visibilities, the FAA stated that obstacles in
the vicinity of an instrument approach are flight-checked and marked on
instrument approach charts. It is less likely that pilots would
encounter unexpected obstacles when following an instrument approach
chart.\414\
---------------------------------------------------------------------------

    \413\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, Final Rule, 79 FR 9946 (Feb. 21, 2014).
    \414\ Id.
---------------------------------------------------------------------------

    The minimums currently prescribed for helicopters in Sec.
135.613(a)(2)(i) and (ii) would not allow a powered-lift to maintain an
acceptable level of obstacle and cloud clearances when conducting VFR
transitions to landing areas because of the anticipated time it will
take to transition from cruise flight to VTOL landing, as well as
speed, distance required to maneuver, and autopilot usage. Airplanes
are not able to use reduced VFR weather minimums when conducting these
types of maneuvers and applying these minimums is consistent with the
FAA's previous determination to require powered-lift to use airplane
weather minimums under part 91 as previously discussed in this NPRM.
Therefore, the FAA proposes in Sec.  194.308(s)(2) that a 1,000-foot
ceiling and 2 SM visibility for powered-lift day operations and a
1,500-foot ceiling and 3 SM visibility for powered-lift night
operations.
    Section 135.613(b) addresses the departure minimums required for
transitions from VFR to IFR. Since the FAA proposes that powered-lift
will be required to use alternate powered-lift minimums for Sec.
135.613(a), the FAA proposes in Sec.  194.308(s)(3) powered-lift use
those same minimums for Sec.  135.613(b)(1) as well.
    Section 135.615(a) requires helicopter air ambulance pilots to
perform pre-flight planning to determine the minimum safe cruise
altitude and to identify and document the highest obstacle along the
planned en route phase of flight prior to conducting VFR operations.
The pilot would use this minimum safe cruise altitude when determining
the minimum required ceiling and visibility for the planned flight.
This rule is intended to prevent obstacle collisions by requiring
pilots to be aware of the terrain and highest obstacles along a planned
route.\415\
---------------------------------------------------------------------------

    \415\ Air Ambulance and Commercial Helicopter Operations, Part
91 Helicopter Operations, and Part 135 Aircraft Operations, Safety
Initiatives and Miscellaneous Amendments, 75 FR 62640, 62651 (Oct.
12, 2010).

---------------------------------------------------------------------------

    The FAA anticipates many powered-lift, other than necessary for
takeoff and landing, in order to gain efficiencies in speed and range,
will prefer to utilize wing-borne flight as long as practical. Since
powered-lift will likely operate similar to an airplane in cruise
flight, they will require more time and distance to make corrections to
their flightpath to avoid other aircraft and obstacles. As a result,
the FAA analyzed whether applying the minimums under Sec.  135.203(a)
would be more appropriate for powered-lift conducting HAA operations
than the minimums outlined under Sec.  135.615. Section 135.203(a)
specifies the VFR minimum altitudes for airplane operations.
Specifically, Sec.  135.203(a)(1) requires an airplane be operated
during the day, at least 500 feet above the surface or no less than 500
feet horizontally from any obstacle. Additionally, Sec.  135.203(a)(2)
requires an airplane be operated at night at an altitude at least 1,000
feet above the highest obstacle within a horizontal distance of 5 miles
from the course intended to be flown or, in designated mountainous
terrain, at least 2,000 feet above the highest obstacle within a
horizontal distance of 5 miles from the course intended to be flown.
The FAA considered the similarities between airplanes and powered-lift
using wing-borne lift during the cruise portions of flight and asserts
that the airplane requirements contained in Sec.  135.203(a)(1) and (2)
are more suited for powered-lift than the helicopter minimums in Sec.
135.203(b). Accordingly, the FAA proposes minimums for powered-lift
operating under subpart L in Sec.  194.308(t)(1).
    Whereas Sec.  135.203(b) requires no minimum VFR altitude for
helicopters, except over congested areas where 300 feet above the
surface is required, helicopters used in air ambulance operations are
required to maintain higher minimum VFR altitudes as stipulated in
Sec.  135.615(b)(1) and (2). Section 135.615(b)(1) and (2) require the
pilot in command of a helicopter to ensure all terrain and obstacles
along the route of flight are cleared vertically by no less than 300
feet during the day and 500 feet at night when conducting a VFR air
ambulance operation.
    A minimum altitude that clears all terrain and obstacles along the
route of flight vertically by no less than the 500 feet during the day,
and at night 1,000 feet, except in mountainous terrain where 2,000 feet
will provide a sufficient distance from terrain and obstacles to ensure
the safe operation of powered-lift conducting air ambulance operations.
The FAA proposes in Sec.  194.308(t)(2) that to comply with the en
route altitude requirements of Sec.  135.615(b)(1) and (2), a powered-
lift conducting a VFR air ambulance operation clear all terrain and
obstacles along the route of flight vertically by the minimum altitudes
and horizontal distances specified in Sec.  135.203(a)(1) and (2).
Similarly, the FAA proposes the pilot in command of a powered-lift use
the minimum altitudes specified in Sec.  135.203(a)(1) and (2) when
making the determinations required by Sec.  135.615(a)(3).
    The FAA also proposes in Sec.  194.308(u) that the pre-flight risk
analysis requirements contained in Sec.  135.617 apply to powered-lift.
This section details several items that must be documented in the
certificate holder's manual regarding pre-flight considerations, such
as human factors, weathers, and other critical considerations. The FAA
imposed these requirements for HAA because ``the FAA and the NTSB . . .
identified several accidents which may have been prevented had a
preflight risk analysis been completed. The NTSB concluded that
``implementation of flight risk evaluation before each mission would
enhance the safety of emergency medical services operations.'' \416\
The considerations that a certificate holder is required to take into
account for helicopter operations are equally important for operations
of powered-lift under subpart L.
---------------------------------------------------------------------------

    \416\ Helicopter Air Ambulance, Commercial Helicopter, and Part
91 Helicopter Operations, Final Rule, 79 FR 9946 (Feb. 21, 2014),
citing NTSB, Special Investigation Report on Emergency Medical
Services Operations (NTSB/SIR-06/01) 4 (Jan. 25, 2006).
---------------------------------------------------------------------------

    Section 135.619 sets out the requirements for an operations control
center. This regulation requires a certificate holder who is authorized
to conduct HAA with 10 or more helicopter air ambulances assigned to
the certificate holder's operations specifications to have an
operations control center. The FAA added the requirement for operations
control centers with the initial codification of Subpart L, stating the
level of operational complexity and management detail required for safe
operations is greater for certificate holders with 10 or more
helicopter air ambulances.\417\ The FAA determined that operational
complexity and management detail required for safe operations in the
dynamic environment envisaged by the air ambulance operations conducted
under Subpart L is not limited to only helicopters, but rather is
dependent on the number of aircraft authorized. Therefore, the FAA
proposes in Sec.  194.308(v) that any operator utilizing helicopters,
powered-lift, or any combination thereof, that total 10 or more of
these aircraft utilized in air ambulance operations would trigger the
requirements to have an operations control center as detailed in Sec.
135.619.
---------------------------------------------------------------------------

    \417\ Id. at 62647.
---------------------------------------------------------------------------

    The FAA also determined, as proposed in Sec.  194.308(w), that it
would be appropriate to apply the briefing requirements contained in
Sec.  135.621 for medical personnel to air ambulance operations that
occur in powered-lift. The FAA determined that it would not be
appropriate to relieve powered-lift operators from the briefing
requirements for medical personnel currently required for helicopter
operators, as powered-lift will be operating in the dynamic requirement
envisaged by subpart L.
2. Part 135 Airplane Rules Addressed in This SFAR
    The FAA analyzed the part 135 regulations and identified airplane
rules appropriate to powered-lift operations. The FAA based this
determination on the ability of a powered-lift to operate in a manner
similar to airplanes. Additionally, the FAA considered the safety
aspects of the rule, whether or not powered-lift have similar operating
and performance characteristics to airplanes, such as wing-borne
flight, higher cruise speeds and operational altitudes. The FAA also
considered the similarities between airplanes and powered-lift in areas
such as takeoff and landing capabilities using wing-borne lift,
maneuverability, range and operating environment. In light of the
proposed changes to air carrier definitions in the Update to Air
Carrier Definitions NPRM, which will affect the applicability of this
part, the FAA assumes, in this rule, that all part 135 requirements
applicable to aircraft, generally, apply to powered-lift.
i. Subpart A: General
    Subpart A prescribes requirements regarding the applicability,
manual requirements, aircraft requirements, and crewmember certificate
requirements for part 135. For those operators required to have a
manual, Sec.  135.23 specifies the required content for that manual. It
is essential for certificate holders of a certain size to have a manual
which sets forth their procedures and policies to ensure the safe
operation of the aircraft they use. The manual content requirements of
a Destination Airport Analysis as specified in Sec.  135.23(r) are only
required if the aircraft meets the thresholds set forth by Sec.
135.385, Large Transport Category Airplanes: Turbine

Engine Powered: Landing limitations: Destination Airports, as specified
for large powered-lift in Sec.  194.307(qq) and (rr).
    The FAA proposes in Sec.  194.307(a) that if the requirements of
Sec.  135.385 are applicable to a specific powered-lift, then all of
the requirements of Sec.  135.23(r), and in particular, Sec.
135.23(r)(7) which currently only applies to airplanes, would be
applicable as well. This proposal will ensure that evaluation of any
inoperative equipment are included in the Destination Airport Analysis,
which is equally important for powered-lift as it would be for
airplanes required to comply with the performance requirements of Sec.
135.385. The FAA expects that powered-lift inoperative equipment would
affect the analysis of runway safety margins at destination airports.
ii. Subpart B: Flight Operations
    Subpart B prescribes requirements for flight operations under part
135. Section 135.93 details minimum altitudes for use of an autopilot.
This section is applicable to all aircraft but contains many references
to an Airplane Flight Manual (AFM) in multiple paragraphs and, in
paragraph (g) excepts rotorcraft operations. The altitude requirements
of this section are in place to provide pilots with sufficient altitude
for obstacle clearance taking into consideration the reaction time
needed to disengage the autopilot and apply a corrective action should
an autopilot malfunction occur.
    An example of a particularly critical autopilot malfunction is a
hard-over, which is when the autopilot pitch control channel commands a
full nose-down deflection of the pitch control surfaces of the
airplane. The FAA anticipates that powered-lift will conduct a majority
of their autopilot-controlled flight operations much like an airplane
(in wing-borne flight mode), with the lift being primarily produced by
the wings providing a greater forward velocity than a helicopter. The
safety measures of this rule, including any autopilot related
limitations contained in the powered-lift's flight manual, and not the
rotorcraft exception, should continue to apply to powered-lift to
ensure the pilot has sufficient altitude to recognize, react, and
recover from an autopilot induced malfunction. As a result, the
aircraft-generic autopilot requirements in Sec.  135.93(a) through (f)
apply to powered-lift, and the FAA proposes in Sec.  194.307(b) to
apply the requirements referencing the ``Airplane'' flight manual to
powered-lift, as reflected in a powered-lift's aircraft flight manual.
    Section 135.100 details flightcrew member duties in relation to
critical phases of flight including all ground operations involving
taxi, takeoff and landing, and all other flight operations conducted
below 10,000 feet, except cruise flight. This rule was codified in 1981
for both parts 121 and 135 operations to improve safety by reducing
flightcrew member distractions caused by non-safety related duties and
activities being conducted during critical phases of flight.\418\
Regardless of the type of aircraft and the type of taxiing they do
(i.e., ground taxi, hover taxi), in order to maintain an equivalent
level of safety for all aircraft, including powered-lift, conducting
operations at an airport, all movement of any aircraft under its own
power at an airport must be done free of distraction from non-safety
related duties and activities.
---------------------------------------------------------------------------

    \418\ Elimination of Duties and Activities of Flight Crewmembers
Not Required for the Safe Operation of Aircraft, 46 FR 5502 (Jan.
19, 1981).
---------------------------------------------------------------------------

    In Sec.  135.100, a note states that taxi is defined as ``movement
of an airplane under its own power on the surface of an airport.'' FAA
ATC defines two means of taxiing for helicopters as hover taxi and air
taxi.\419\ Upon review of this regulation, the FAA determined that the
term taxi should not be limited to airplanes and should be applicable
to all aircraft conducting taxi maneuvers at an airport. The note at
the time of this rule did not conceptualize helicopters taxiing on
wheels on a taxiway as well as a potential for powered-lift that might
also be able to taxi in this manner. Powered-lift may have the design
and capability to taxi in a manner similar to airplanes, helicopters,
or both. The intent of the rule is to provide for a sterile cockpit
during critical phases of flight to improve safety by reducing
distractions, which is also applicable to powered-lift operations. As a
result, the FAA proposes amending the definition as a permanent change
in Sec.  135.100 to replace the word ``airplane'' with ``aircraft,''
making the section applicable to not only airplanes, but also
helicopters and powered-lift.
---------------------------------------------------------------------------

    \419\ FAA Order 7110.65W (Dec. 10, 2015) Chapter 3, Section 11.
---------------------------------------------------------------------------

    Section 135.128 regulates the use of safety belts and child
restraint systems. This section requires that each person onboard an
aircraft operated under part 135 occupy an approved seat or berth with
a separate safety belt properly secured about him or her during
movement on the surface, takeoff, and landing. For seaplane and float
equipped rotorcraft operations during movement on the surface, the
person pushing off the seaplane or rotorcraft from the dock and the
person mooring the seaplane or rotorcraft at the dock are excepted from
the seating and safety belt requirements.
    In 1992 when the FAA published a final rule \420\ that revised
Sec.  135.128, it indicated that it agreed with a comment received
regarding seaplane operations, in that a pilot would be unable to moor
or launch a seaplane or a float equipped rotorcraft, unless a pilot or
passenger has their safety belt or shoulder harness unfastened so that
they can vacate their seat for the purpose of launching or mooring the
seaplane or float equipped rotorcraft. The same exception should also
apply to a powered-lift that is properly equipped to conduct operations
on water. The FAA proposes in Sec.  194.307(c) to apply the exception
delineated in Sec.  135.128(a) to powered-lift pilots or passengers
when the powered-lift is operating like a seaplane or a float equipped
rotorcraft.
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    \420\ Miscellaneous Operational Amendments, 57 FR 42662 (Sep.
15, 1992).
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iii. Subpart C: Aircraft and Equipment
    Subpart C prescribes requirements for aircraft and associated
equipment for operations under part 135. Section 135.145 sets out the
parameters and the requirements for the Proving and Validation Tests
that must be accomplished by a certificate holder. Proving tests are
necessary to evaluate each certificate holder's ability to conduct
operations safely and in accordance with the applicable regulations.
Proving tests under Sec.  135.145 consist of a demonstration of the
certificate holder's ability to operate and maintain certain aircraft
new to the operator's fleet or the certificate holder's ability to
conduct a particular kind of operation. Additionally, it is each
certificate holder's responsibility to show that they can operate each
of their aircraft safely and in compliance with the requirements of the
regulations and their procedures. Section 135.145(b) requires that a
certificate holder conduct proving tests in a turbojet airplane if they
have not previously proved a turbojet airplane. Powered-lift,
regardless of the powerplant, have additional complexity due to their
design and operation and that these features have not been available
and experienced by the civilian market to date. To ensure powered-lift
operate to the highest level of safety in part 135, the FAA is
proposing in Sec.  194.307(d) that if a certificate holder has not
previously proven a powered-lift in operations under part 135, they be

required to conduct at least 25 hours of proving tests acceptable to
the FAA as detailed in Sec.  135.145(b)(1) through (3).
    The FAA requires validation testing for certain authorizations, and
for the addition of certain aircraft that were previously proved or
validated but are not of the same make or model, or of similar design.
The requirements of Sec.  135.145(d)(2) through (4) are not aircraft
specific and would apply to an operator utilizing powered-lift and
requesting authorization to conduct these types of operations. Section
135.145(d)(1) requires validation tests for the addition of an aircraft
that requires two pilots for flight in VFR conditions, or turbojet
airplanes. The FAA proposes in Sec.  194.307(e) that, for the same
reasons cited above for proving tests, validation testing required by
Sec.  135.145(d)(1) apply to all powered-lift. Therefore, the FAA
proposes validation testing be required when an operator requests
authorization to use a powered-lift, unless a powered-lift of the same
make or similar design has been previously proved or validated by that
operator in operations under part 135.
    In 1989, the FAA revised the equipment requirements and moved them
into a new section, Sec.  135.150, which requires a public address and
crewmember interphone systems for aircraft that have a passenger
seating configuration of more than 19, excluding any pilot seat.\421\
The public address system required by Sec.  135.150(a) is generic to
all aircraft; however, under paragraph (a)(7), transport category
airplanes manufactured on or after November 27, 1990, must meet the
requirements of Sec.  25.1423. The crewmember interphone system
required by Sec.  135.150(b) is also generic to aircraft; however, for
large turbojet-powered airplanes, they must meet the additional
requirements contained in paragraph (b)(7). This section increases
airplane safety by facilitating the rapid evacuation of passengers
during emergency conditions. Section 135.150 works in conjunction with
Sec.  25.1423, which requires any public address (PA) system that is
required for use in air carrier service to be powered by a source that
remains powered when the aircraft is in flight or stopped on the
ground, after the shutdown or failure of all engines and auxiliary
power units, or the disconnection or failure of all power sources
dependent on their continued operation. Additionally, the PA system
must incorporate specific design features, accessibility requirements,
and be able to operate for a specified period of time. The crewmember
interphone system requirement established in Sec.  135.150(b) was
originally promulgated to ensure the safety and security of
passengers.\422\ The FAA noted that an aircraft of more than 19
passenger seats was of the size that would benefit from the safety
advantages of having a crewmember interphone and public address system
installed.\423\ A powered-lift with more than 19 passenger seats will
also benefit from a crewmember interphone and PA system. Additionally,
due to the design features of some powered-lift, such as multiple
rotating blade assemblies, it will be essential for the flightcrew to
be able to communicate with the cabin crew and passengers during an
emergency evacuation. This will promote safe, effective evacuations of
these aircraft. The FAA proposes in Sec.  194.307(f) that for large
powered-lift, the public address system required by Sec.  135.150(a)(7)
comply with Sec.  25.1423 or such airworthiness criteria as the FAA may
find provide an equivalent level of safety in accordance with Sec.
21.17(b). Additionally, the FAA proposes in Sec.  194.307(g) that for
large powered-lift that have more than 19 passenger seats, regardless
of the type of powerplant, the crewmember interphone system comply with
the requirements of Sec.  135.150(b)(7) or such airworthiness criteria
as the FAA may find provide an equivalent level of safety in accordance
with Sec.  21.17(b). The FAA acknowledges that while no powered-lift
that have more than 19 passenger seats are currently undergoing type
certification such aircraft may be developed in the future.
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    \421\ See Independent Power Source for Public Address System in
Transport Category Airplanes, 54 FR 43922 (Oct. 27, 1989).
    \422\ Independent Power Source for Public Address System in
Transport Category Airplanes, 54 FR 43926 (Oct. 27, 1989).
    \423\ Id.
---------------------------------------------------------------------------

    Section 135.151 requires cockpit voice recorders (CVRs) on certain
turbine-powered airplanes and rotorcraft. CVRs enhance safety and are
required in turbine-powered airplanes and rotorcraft carrying a certain
passenger count as a necessary hazard analysis tool used during an
accident investigation. The FAA asserted as early as 1978 that
consideration should be given to requiring Ground Proximity Warning
Systems (GPWS), CVR, and FDR equipment on turbojet-powered airplanes
with 10 or more passenger seats due to the complexity and high-
performance characteristics of those airplanes.\424\ CVRs provide
accident investigation information that is unattainable from any other
source, with valuable auditory information such as sounds captured in
the cockpit. These sources of information aid in determining causal and
contributing factors in accident and incident investigation. Amendments
issued in response to NTSB recommendations as well as congressional
mandates identify the FAA's broader responsibility to apply these
appropriately to all aircraft with certain seating capacities.\425\
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    \424\ Air Taxi Operators and Commercial Operators, 43 FR 46759
(Oct. 10, 1978).
    \425\ Cockpit Voice Recorders and Flight Recorders, Final Rule,
53 FR 26135 (Jul. 11, 1988).
---------------------------------------------------------------------------

    Section 135.151(a) requires a multiengine, turbine-powered airplane
or rotorcraft having a passenger seating configuration of six or more
and for which two pilots are required by certification or operating
rules to be equipped with an approved cockpit voice recorder that meets
various CVR installation requirements provided by the airworthiness
standards for normal category airplanes or rotorcraft, or transport
category airplanes or rotorcraft, as applicable. Section 135.151(b)
requires a multiengine, turbine-powered airplane or rotorcraft having a
passenger seating configuration of 20 or more to be equipped with an
approved CVR that meets various CVR installation requirements provided
by the airworthiness standards for normal category airplanes or
rotorcraft, or transport category airplanes or rotorcraft, as
applicable. Both Sec.  135.151(a) and (b) further require that the
cockpit voice recorder be operated continuously from the use of the
check list before the flight to completion of the final check list at
the end of the flight.
    Section 135.151(d) requires large turbine-powered airplanes
manufactured after October 11, 1991 to be equipped to record
uninterrupted audio signals received by a boom or mask microphone in
accordance with Sec.  25.1457(c)(5). Paragraph (d) also requires that
on these aircraft equipped to record the uninterrupted audio signals
received by a boom or a mask microphone, the flightcrew members must
use the boom microphone below 18,000 feet mean sea level.
    Section 135.151(g) applies to aircraft manufactured on or after
April 7, 2010, which includes the caveat that if the aircraft is also
required to have a flight data recorder (FDR) under Sec.  135.152, then
the aircraft must have a CVR that meets the requirements listed in
paragraph (g)(1) (applicable to multiengine, turbine-powered airplanes
or rotorcraft with a passenger seating configuration of six or more
seats and for which two pilots are required by certification or
operating rules) or (g)(2) (applicable to multiengine, turbine-

powered airplanes or rotorcraft with a passenger seating configuration
of 20 or more seats). Such aircraft equipped with an FDR have different
requirements for cockpit voice recorders because the FAA found that,
for newly manufactured aircraft also required to have a flight data
recorder, ``evidence of benefit in changes to wiring systems that could
prevent inadvertent shutdown of power sources, and for an independent
power supply for CVRs.'' \426\
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    \426\ Revisions to Cockpit Voice Recorder and Digital Flight
Data Recorder Regulations, 70 FR 9751 (February 28, 2005).
---------------------------------------------------------------------------

    Section 135.151(h) applies to all airplanes and rotorcraft that are
required by this part to have a CVR and a FDR that also have datalink
communication equipment that was installed on or after December 6,
2010. For those aircraft, all datalink messages must be recorded.
    For the same reasons the FAA imposed the CVR requirements for
certain airplanes and rotorcraft, the FAA proposes to require CVRs for
powered-lift with similar seating configurations and pilot
requirements. Specifically, the FAA proposes, regardless of the types
of powerplant, that powered-lift which have a passenger seating
configuration of six or more and for which two pilots are required by
certification or operating rules, or that have a passenger seating
configuration of 20 or more seats will be required to comply with
paragraph (a), (b), or (g), based upon the passenger seating
configuration and whether an FDR is required under Sec.  135.152. These
proposals are contained in Sec.  194.307(h), (i), (k), and (l). The FAA
also proposes in Sec.  194.307(j) and (m) that although paragraphs (d)
and (h) reference airplanes or rotorcraft, these paragraphs will also
apply to powered-lift to ensure they appropriately record uninterrupted
audio signals and that all datalink messages are recorded when
required. The FAA intends to include CVR airworthiness requirements
during type certification based on an applicant's proposed operational
needs. Operators will need to ensure that the CVR for each powered-lift
be installed and equipped in accordance with the certification
provisions listed in the applicable paragraph of Sec.  135.151 or such
airworthiness criteria as the FAA may find provide an equivalent level
of safety in accordance with Sec.  21.17(b).
    The FAA is proposing in Sec.  194.307(n) to apply flight data
recorder requirements of Sec.  135.152 to powered-lift because of the
same rationale discussed previously for Sec.  135.151. Section
135.152(a) requires that a multiengine, turbine-engine powered airplane
or rotorcraft having a passenger seating configuration, excluding any
required crewmember seat, of 10 to 19 seats, that was either brought
onto the U.S. register after, or was registered outside the U.S. and
added to the operator's U.S. operations specifications after October
11, 1991, to be equipped with one or more approved flight recorders
that uses a digital method of recording and storing data and a method
of readily retrieving that data from the storage medium. Additionally,
this paragraph requires that the flight recorder must retain no less
than 25 hours of aircraft operation. The FAA proposes in Sec.
194.307(o) that a powered lift, regardless of the type of powerplant,
that otherwise meets the threshold requirements of this paragraph be
required to comply with this paragraph. However, paragraph (a)
specifies that the parameters for the flight recorder that must be
recorded are contained in part 135, appendix B or C, which are specific
to airplanes or rotorcraft. As discussed extensively throughout this
preamble, powered-lift are manufactured combining the design features
of an airplane and helicopter with complex systems. The FAA does not
have sufficient experience and knowledge of every possible design type
of powered-lift, as most powered-lift are still in development.
    Accordingly, in place of appendices B and C to part 135,\427\ the
FAA has drafted new flight data recorder tables, which appear in
proposed Sec. Sec.  194.314 and 194.315,\428\ which outline the FDR
specifications for powered-lift under part 135. In developing these
tables, the FAA applied the FDR requirements from the airplane and
helicopter appendices to powered-lift, dependent on which operational
flight mode is in use (i.e., wing-borne flight mode or vertical-lift
flight mode). In addition, the FAA replaced helicopter-specific
nomenclature to accommodate powered-lift. For example, helicopter
flight controls, as written, describe pedals and collective controls,
which may not apply to powered-lift. In addition, the FAA changed the
terminology that provided directional controls for ``ascent and
descent''. Notwithstanding slight nomenclature changes within the
parameters, the FAA did not change the other information and numbers
within the appendices. The FAA invites comments on these draft tables
to ensure that the FAA has adequately addressed all of the requirements
for these novel aircraft.
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    \427\ See appendix B to part 135, Airplane Flight Recorder
Specifications, and appendix C to part 135, Helicopter Flight
Recorder Specifications, 14 CFR part 135.
    \428\ The SFAR tables are found in the regulatory text within
the SFAR amendment.
---------------------------------------------------------------------------

    Section 135.152(b) applies to multiengine turbine-powered airplanes
having a passenger seating configuration of 20 to 30 seats and to
multiengine turbine-powered rotorcraft having a passenger seating
configuration of 20 or more seats. Paragraph (b) requires these
aircraft to be equipped with one or more approved flight recorders that
utilize a digital method of recording and storing data and a method of
readily retrieving that data from the storage medium. Additionally,
paragraphs (b)(1) and (2) provide the FDR parameters that are required
for aircraft type certificated before and after October 1, 1969. After
this date, the number of mandatory parameters an aircraft must record
are determined by the date of aircraft type certification of that
aircraft. Paragraph (b)(3) requires that the FDRs on the aircraft
referenced in paragraph (b) introductory text \429\ manufactured after
October 11, 1991, must record all the parameters outlined in appendix D
or E to part 135. Currently, the FAA is not aware of any powered-lift
designs that contain 20 or more passenger seats; however, should an
applicant seek to certificate a powered-lift with a passenger seating
configuration of 20 or more seats, the FAA proposes in Sec.  194.307(p)
that paragraphs (b) introductory text and (b)(3) apply to these
aircraft, regardless of the type of powerplant. Because the FAA does
not anticipate any powered-lift with this seating configuration to be
developed during the term of this SFAR, the FAA has determined it will
not create a new FDR table that addresses powered-lift of this size at
this time. For potential future rulemaking, the FAA welcomes input on
the FDR parameters that would be essential for a powered-lift of this
size.
---------------------------------------------------------------------------

    \429\ As mentioned above, paragraph (b) applies to multiengine
turbine-powered airplanes with a passenger seating configuration of
20 to 30 seats and to multiengine turbine-powered rotorcraft with a
passenger seating configuration of 20 or more seats.
---------------------------------------------------------------------------

    Section 135.152(c) requires that an installed flight recorder be
operated continuously from the instant the airplane begins the takeoff
roll or the rotorcraft begins the lift-off and until the airplane has
completed the landing roll or the rotorcraft has landed at its
destination. Powered-lift may perform takeoffs and landings similar to
airplanes or rotorcraft; accordingly, the FAA proposes in Sec.
194.307(n)(3) to apply the requirements of Sec.  135.152(c) to powered-
lift with a passenger seating configuration, excluding crewmember
seats, of 10 to 30, whenever the takeoff

roll or lift off begins and until the landing is completed.
    Paragraph (d) in Sec.  135.152 requires the certificate holder to
keep certain recorded data for a specified time. Paragraph (d) requires
the certificate holder to keep the recorded data until the airplane has
been operating for at least 25 hours and, for a rotorcraft, 10 hours.
The difference in the amount of FDR recorded data required for
rotorcraft versus airplanes was because the FAA agreed that rotorcraft
typically operate short-haul flights and that a 10-hour requirement is
adequate for rotorcraft.\430\ Although the range is expected to be
closer to that of a rotorcraft, the precise range of future powered-
lift is uncertain and thus, conservatively, the FAA is proposing to
apply the 25-hour requirement currently applicable to airplanes.
Accordingly, the FAA has considered both recorded data requirements of
Sec.  135.152(d) and proposes in Sec.  194.307(n)(2) to require
certificate holders to keep the data until the powered-lift has been
operating for at least 25 hours. This requirement would be applicable
to powered-lift with a passenger seating configuration, excluding
crewmember seats, of 10 to 30.
---------------------------------------------------------------------------

    \430\ Cockpit Voice Recorders (CVR) and Flight Recorders, 53 FR
26134 (Jul. 11, 1988).
---------------------------------------------------------------------------

    The FAA has determined that Sec.  135.152(e) is already applicable
to powered-lift because it applies to aircraft; accordingly, in the
event of any accident or occurrence that requires the immediate