[Federal Register: November 23, 2009 (Volume 74, Number 224)]
[Proposed Rules]
[Page 61055-61067]
[DOCID:fr23no09-18]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 121

[Docket No. FAA-2009-0675; Notice No. 09-07]
RIN 2120-AJ43

Part 121 Activation of Ice Protection

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This action would amend the regulations applicable to
operators of certain airplanes used in Title 14 Code of Federal
Regulations part 121 operations and certificated for flight in icing
conditions. The proposed standards would require either the
installation of ice detection equipment or changes to the Airplane
Flight Manual to ensure timely activation of the airframe ice
protection system. This proposed regulation is the result of
information gathered from a review of icing accidents and incidents,
and it is intended to improve the level of safety when airplanes are
operated in icing conditions.

DATES: Send your comments on or before February 22, 2010.

ADDRESSES: You may send comments identified by Docket Number FAA-2009-
0675 using any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov and follow the online instructions for sending your
comments electronically.
     Mail: Send comments to Docket Operations, M-30; U.S.
Department of Transportation, 1200 New Jersey Avenue, SE., Room W12-
140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Bring comments to Docket
Operations Room W12-140 of the West Building Ground Floor at 1200 New
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
     Fax comments to Docket Operations at<PHONE_NUMBER>.
    For more information on the rulemaking process, see the
SUPPLEMENTARY INFORMATION section of this document.
    Privacy: The FAA will post all comments received, without change,
to http://www.regulations.gov, including any personal information you
provide. Using the search function of our docket Web site, anyone can
find and read the electronic form of all comments received into any of
our dockets, including the name of the individual sending the comment
(or signing the comment for an association, business, labor union,
etc.). You may review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78) or you
may visit http://DocketsInfo.dot.gov.
    Docket: To read background documents or comments received, go to
http://www.regulations.gov at any time and follow the online
instructions for accessing the docket. Or, go to Docket Operations in
Room W12-140 of the West Building Ground Floor at 1200 New Jersey
Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through
Friday, except Federal holidays.
    Contacts for Further Information: For operational questions about
the proposed rule contact Jerry Ostronic, FAA, Air Carrier Operations
Branch, AFS-220, Flight Standards Service, 800 Independence Ave., SW.,
Washington, DC 20591; telephone<PHONE_NUMBER>; facsimile (202) 267-
5229, e-mail<EMAIL_ADDRESS>    For aircraft certification questions about the proposed rule
contact Robert Jones, FAA, Propulsion/Mechanical Systems Branch, ANM-
112, Transport Airplane Directorate, Aircraft Certification Service,
1601 Lind Avenue, SW., Renton, WA 98057-3356; telephone<PHONE_NUMBER>;
facsimile<PHONE_NUMBER>, e-mail<EMAIL_ADDRESS>    For legal questions about the proposed rule contact Douglas
Anderson, FAA, Office of Regional Counsel, Federal Aviation
Administration, 1601 Lind Avenue, SW., Renton, Washington 98057-3356;
telephone<PHONE_NUMBER>; fax:<PHONE_NUMBER>, e-mail
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Later in this preamble, under the Additional
Information section, the FAA discusses how you can comment on this
proposal and how the agency will handle your comments. Included in this
discussion is related information about the docket, privacy, and the
handling of proprietary or confidential business information. The FAA
also discusses how you can get a copy of this proposal and related
rulemaking documents. Instructions for accessing the docket appear
under the ADDRESSES heading of this notice of proposed rulemaking
(NPRM). Appendix 1 of this preamble defines terms used in the preamble
of this NPRM.

Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in
Title 49 of the United States Code. Subtitle I, section 106 describes
the authority of the FAA Administrator. Subtitle VII, Aviation
Programs, describes in more detail the scope of the agency's authority.
    This rulemaking is promulgated under the authority described in
subtitle VII, part A, subpart III, section 44701, ``General
requirements.'' Under that section, the FAA is charged with promoting
safe flight of civil aircraft in air commerce by prescribing minimum
standards required in the interest of safety for the design and
performance of aircraft; regulations and minimum standards of safety
for inspecting, servicing, and overhauling aircraft; and regulations
for other practices, methods, and procedures the Administrator finds
necessary for safety in air commerce. This regulation is within the
scope of that authority because it prescribes new safety standards for
the operation of certain airplanes used in air carrier service.

I. Background

    On October 31, 1994, an accident involving an Avions de Transport
Regional ATR 72 series airplane occurred in icing conditions. This
prompted the FAA to initiate a review of aircraft safety in icing
conditions and determine what changes could be made to increase the
level of safety. In May 1996, the FAA sponsored the International
Conference on Aircraft

Inflight Icing, where icing specialists recommended improvements to
increase the level of safety of aircraft operating in icing conditions.
The FAA reviewed the conference recommendations and developed a
comprehensive, multi-year icing plan. The FAA Inflight Aircraft Icing
Plan, dated April 1997,\1\ described various activities the FAA was
considering to improve aircraft safety when operating in icing
conditions. In accordance with the FAA Inflight Aircraft Icing Plan,
the FAA tasked the Aviation Rulemaking Advisory Committee (ARAC) \2\ to
consider the need for ice detectors or other means to warn flightcrews
early about ice accreting on critical surfaces requiring crew action.
The work would be carried out by ARAC's Ice Protection Harmonization
Working Group (IPHWG). This proposed rule is based on ARAC's
recommendations to the FAA, which may be found in the docket for this
rulemaking, docket FAA-2009-0675.
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    \1\ FAA Inflight Aircraft Icing Plan, dated April 1997, is
available in the Docket.
    \2\ Published in the Federal Register, December 8, 1997 (62 FR
64621).
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A. Existing Regulations for Flight in Icing Conditions

    Currently, the certification regulations applicable to airplanes
for flight in icing conditions require that the airplane must be able
to operate safely in the continuous maximum and intermittent maximum
icing conditions of appendix C.\3\ Amendment 25-121 to 14 CFR part 25,
which applies to transport category airplanes, added specific
requirements for airplane performance and handling qualities for flight
in icing conditions.\4\ Recently, the FAA adopted Amendment 25-129 \5\
to add requirements in Sec.  25.1419 to provide means to ensure timely
activation of ice protection systems. These requirements will apply to
airplanes type certificated in the future. The regulations for
airplanes certificated under part 23 (non-transport) require that ``a
means be identified or provided for determining the formation of ice on
critical parts of the airplane * * *''
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    \3\ Section 25.1419, Ice Protection.
    \4\ 72 FR 44656 (August 8, 2007).
    \5\ 74 FR 38328 (August 3, 2009).
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    Parts 91, 121, and 135 contain regulations that apply to airplane
operations in icing conditions. Operating regulations under parts 91
and 135 address limitations in icing conditions for airplanes operated
under those regulations.\6\ Part 121 addresses operations in icing
conditions that might adversely affect safety and regulates
installation of certain types of ice protection and wing illumination
equipment.\7\
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    \6\ 14 CFR 91.527, Operating in icing conditions; and Sec.
135.227, Icing conditions: Operating limitations.
    \7\ 14 CFR 121.629(a), Operation in icing conditions and Sec.
121.341, Equipment for operations in icing conditions.
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    Neither the current operating regulations nor the certification
regulations in effect before the recent adoption of Amendment 25-129
require a means to ensure timely activation of ice protection systems.
This proposed rule would provide a standard to ensure that ice
protection systems on in-service part 121 airplanes are activated in a
timely way to ensure safe flight in icing conditions.

B. National Transportation Safety Board Safety Recommendations

    This proposal addresses Safety Recommendation No. A-07-14 \8\
issued by the National Transportation Safety Board (NTSB) on the
subject of airframe icing. That NTSB safety recommendation is a result
of a Cessna Citation 560 series airplane accident near Pueblo, Colorado
on February 16, 2005, in which the airplane crashed and eight people
died. The accident airplane had been operating in icing conditions, and
the flightcrew had not activated the airframe ice protection system
during approach, as was required for those operating conditions by the
Airplane Flight Manual (AFM). The NTSB recommended that manufacturers
and operators of pneumatic-deicing-boot-equipped airplanes be required
to revise their AFM, operating manuals, and training programs to
emphasize that leading-edge deicing boots should be activated as soon
as the airplane enters icing conditions.
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    \8\ NTSB recommendation A-07-14 is available in the Docket and
on the Internet at: http://www.ntsb.gov/Recs/letters/2007/A07_12_
17.pdf.
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C. Authorities

1. Federal Aviation Administration
    Title 14 CFR part 25 contains the U.S. airworthiness standards for
type certification of transport category airplanes. These standards
apply to airplanes manufactured within the U.S. and to airplanes
manufactured in other countries and imported to the U.S. under a
bilateral airworthiness agreement.
2. Joint Aviation Authorities
    The Joint Airworthiness Requirements (JAR)-25 contain the
airworthiness standards of the Joint Aviation Authorities (JAA) of
Europe for type certification of transport category airplanes. Thirty-
seven European countries accept airplanes type certificated to JAR-25
standards. These countries also accept airplanes manufactured in the
U.S. that are type certificated to JAR-25 standards for export to
Europe.
3. European Aviation Safety Agency
    The European Aviation Safety Agency (EASA) was established by the
European community to develop standards to ensure safety and
environmental protection, oversee uniform application of those
standards, and promote them internationally. EASA formally became
responsible for certification of aircraft, engines, parts, and
appliances on September 28, 2003. EASA has assumed most of the
functions and activities of the JAA, including its efforts to harmonize
the European airworthiness certification regulations with those of the
U.S.
    The JAR-25 standards have been incorporated into EASA's
``Certification Specifications for Large Aeroplanes'' (CS-25) in
similar if not identical language. EASA's CS-25 became effective
October 17, 2003.

D. Harmonization of U.S. Standards With Those of Other Countries

    The airworthiness standards proposed in this NPRM were developed
before EASA began operations. They were developed in coordination with
the JAA, United Kingdom Civil Aviation Authority, and Transport Canada.
None of these civil aviation authorities have initiated rulemaking to
adopt the proposed standards.

E. Related Rulemaking Activity

    A final rule titled ``Activation of Ice Protection'' was published
on August 3, 2009.\9\ It amends Sec.  25.1419 by requiring a method to
ensure timely activation of the airframe ice protection systems (IPS).
It also adds requirements to reduce flightcrew workload associated with
operation of an airframe IPS that operates cyclically, and to ensure
that procedures for operation of an airframe IPS are included in the
AFM. Those changes affect new airplane certification for flight in
icing conditions. In contrast, this proposed rule is concerned with
timely airframe IPS activation for in-service airplanes.
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    \9\ 74 FR 38328.
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F. Advisory Material

    In addition to this NPRM, the FAA has developed Advisory Circular
(AC) 121.321, ``Compliance with the Requirements of Sec.  121.321.''
That proposed AC would provide guidance

for one acceptable means, but not the only means, of demonstrating
compliance with this proposed rule. The draft AC has been released
concurrently with this NPRM. It is posted on the ``Aircraft
Certification Draft Documents Open for Comment'' Web site, http://
www.faa.gov/aircraft/draft_docs. The Web site will indicate the date
comments are due.

II. Discussion of the Proposal

A. Safety Concern

    The ARAC IPHWG, as a result of the FAA's tasking, reviewed icing
events. The IPHWG found accidents and incidents where the flightcrew
were either completely unaware of ice accretion on the airframe, or
were aware of ice accretion but judged it not significant enough to
warrant operation of the airframe IPS. The FAA agreed with the ARAC
recommendation for rulemaking that would require that flightcrews have
a clear means to know when to activate the airframe IPS.

B. Means To Address the Safety Concern

1. Airworthiness Directives
    The FAA has issued airworthiness directives (AD) to address when to
activate the airframe IPS on several types of airplanes. These ADs
require activation of pneumatic deicing boots at the first signs of ice
accretion on the airplane. This requirement relieves the pilot of the
responsibility for determining whether the amount of ice accumulated on
the wing warrants airframe IPS activation. But activation of the
pneumatic deicing boots is still subject to the flightcrew's
observation of ice accretions, and such observations can be difficult
during times of high workload, during operations at night, or when
clear ice has accumulated. The difficulties associated with observing
ice accretions are applicable to any airframe IPS that relies on the
flightcrew's observations for activating the system, not just pneumatic
deicing boots, so those ADs are not adequate to address the safety
concern that is the focus of this proposed rulemaking. The FAA has
determined, however, that because the cruise phase of flight entails a
lower workload than other phases of flight, activation of the deicing
boots based on flightcrew observation of ice accretions during this
phase of flight is acceptable.
2. A Primary Ice Detection System
    The IPHWG concluded that installing a device to alert the
flightcrew to activate the airframe IPS would be a better way to
address the safety concern than solely relying on the flightcrew's
observation of ice accretion to determine when to activate the IPS. The
FAA has determined that a primary ice detection system would be one
acceptable means to meet the objectives of this proposed rule. Such a
system typically consists of two independent detectors (an advisory ice
detection system typically has only one detector). A primary ice
detection system has sufficient performance and reliability levels that
the flightcrew does not need to monitor icing conditions. A primary ice
detection system could either automatically activate the airframe IPS
or indicate to the flightcrew when to activate the system. There are
several types of airplanes currently in operation that have primary ice
detection systems installed, and the FAA agrees with the IPHWG
determination that these airplanes already meet the desired level of
safety.
3. An Advisory Ice Detection System and Visual Cues
    An advisory ice detection system typically consists of one
detector. Such a system does not have sufficient reliability to be the
primary means of determining when the airframe IPS must be activated.
With an advisory ice detection installed, it is still the flightcrew's
responsibility to make the determination to activate the IPS. However,
the advisory ice detection system would provide a much higher level of
safety than visual cues alone and would mitigate the effects of human
sensory limitations and inadequate attention resulting from workload.
    An advisory ice detection system, in conjunction with visual cues
that pilots can use to identify icing accumulation, would also be an
acceptable means of alerting the flightcrew to activate the airframe
IPS and meet the objectives of this proposed rule. If this method is
used, however, its acceptability would be contingent upon the
following:
     The advisory ice detection system would indicate to the
crew when icing conditions exist.
     The flightcrew would activate the airframe IPS based on
either their observation of the first sign of ice accretion or an alert
from the advisory ice detection system indicating the presence of ice,
whichever occurs first. This activation would not depend on determining
the thickness of the accretion.
4. Operating the Ice Protection System Continuously
    The FAA agrees with the IPHWG conclusion that an acceptable means
of meeting the objectives of this proposed rule would be to require
operating the airframe IPS continuously whenever the airplane is
operating in conditions conducive to airframe icing, except in the
cruise phase of flight (discussed below). To accomplish this, the
flightcrew would activate the airframe IPS in response to a specific
air temperature threshold and the presence of visible moisture. Because
ambient temperature is indicated by flight deck instruments and the
flightcrew can readily observe visible moisture, deciding when to
initiate the system would require little increased effort on the part
of the flightcrew.

C. The Proposed Rule

    The proposed rule would be applicable to airplanes with a
certificated maximum takeoff weight (MTOW) less than 60,000 pounds.
Proposed Sec.  121.321 would require that, 24 months after the
effective date of the final rule, no person may operate an airplane
with a certificated MTOW less than 60,000 pounds in conditions
conducive to airframe icing unless the airframe IPS is operated in
accordance with the proposed section. To address flight in icing
conditions, proposed Sec.  121.321(a) would require one of the
following:
    (1) A primary ice detection system and automatic or manual
activation of the airframe IPS upon notice from the primary ice
detection system that activation is necessary, as well as initiation of
any other operational procedures for operating in icing conditions
specified in the AFM; or
    (2) Both visual cues and an advisory ice detection system, either
of which enable the flightcrew to determine when the airframe IPS must
be activated, activation of the primary airframe IPS when either of
those means indicate it is necessary, and initiation of any other
operational procedures for operating in icing conditions specified in
the AFM; or
    (3) If the airplane is not equipped to comply with either of the
above two options, activation of the airframe IPS and initiation of
approved procedures for operating in airframe icing conditions during
climb, holding, maneuvering for approach and landing, and any other
operation at approach or holding airspeeds, when in conditions
conducive to airframe icing. However, if this option is specifically
prohibited in the AFM, then proposed Sec.  121.321(b) would require
either (1) or (2) above.
    Proposed Sec.  121.321(a) would also require that if option (a)(3)
is selected, the airframe IPS must be activated and operated at the
first sign of ice formation anywhere on the airplane during any

other phase of flight besides climb, holding, and maneuvering for
approach and landing, except where the AFM specifies that the airframe
IPS should not be used.
    Proposed Sec.  121.321(c) would require that procedures for
operating the airframe IPS be included in the AFM for airplanes that
comply with proposed Sec.  121.321(a)(1) or (a)(2). For airplanes that
comply with proposed Sec.  121.321(a)(3), the procedures must be in the
AFM or in the air carrier's operations manual required by Sec.
121.133.
    Proposed Sec.  121.321(d) would require the AFM or the manual
required by Sec.  121.133 to address initial activation, operation
after initial activation, and deactivation of the airframe IPS. This
proposed provision would allow continuous operation, automatic cycling,
or manual cycling of the airframe IPS, depending on the design of the
airplane's airframe IPS. For airplanes equipped with ice detection
systems, this proposed paragraph would require cycling, either manual
or automatic, each time ice is detected.
    Certain IPSs use fluids that lower the freezing point of water.
Unlike other IPSs, fluid systems have a limited duration of ice
protection that is related to the capacity of fluid that the airplane
can carry. These systems need additional evaluation. Therefore, for
airplanes equipped with fluid ice protection systems to comply with
proposed Sec.  121.321, two issues must be addressed:
     System design. The system design must have adequate fluid
capacity to ensure that the airplane/flightcrew can comply with this
proposed rule.
     AFM Dispatch Instructions. The AFM must contain
information to ensure that the system is serviced with the appropriate
amount of fluid for each flight to ensure that the airplane/flightcrew
can comply with this proposed rule.
    For airplanes without ice detection systems, this proposed rule
also allows manual cycling based on time intervals. Recently adopted 14
CFR 25.1419(g) requires transport category airplanes to be equipped
with an ice detection system that alerts the pilot when to activate the
airframe IPS if the ice protection is not either operated continuously
in icing conditions or automatically activated. However, it does not
allow manual cycling of the IPS based on time intervals. Therefore,
manual cycling based on time intervals would be allowed only for
airplanes without Sec.  25.1419(g) in their certification basis. This
would allow the existing airplane fleet to comply with this proposed
rule without modifying the airframe IPS.
    The modifications to airplanes to install ice detection systems to
comply with this proposed rule would likely be complex. They would
require thorough testing and analysis to ensure that the ice detection
systems perform their intended function when installed on the airplane.
Therefore, the FAA proposes in Sec.  121.321(e) that these
modifications would require approval through an amended or supplemental
type certificate in accordance with 14 CFR part 21. In the normal
course of equipment approval, any revised procedures and/or limitations
associated with such modifications would also need to be addressed in
the AFM under Sec. Sec.  23.1581 or 25.1581.

D. Affected Airplanes

    The ARAC's recommendation was limited to airplanes with a
certificated MTOW of less than 60,000 lbs. A limited analysis of past
icing events revealed that airplanes with certificated MTOWs greater
than 60,000 lbs. have not experienced accidents due to in-flight icing,
while airplanes with lower certificated MTOWs have an event history.
Since certificated MTOW is simple to discern, well-understood, and will
address airplanes that have had an event history, the IPHWG recommended
it be adopted as the discriminating parameter and the FAA agrees.
    The FAA requests comment on whether this proposed rule, if adopted,
should be applied to airplanes larger than 60,000 pounds MTOW. For
example, initial indications were that icing may have been implicated
in a recent accident near Buffalo, New York, involving an airplane with
a MTOW slightly greater than 60,000 pounds. While subsequent
investigation indicates that icing was not implicated in this accident,
if this rule applied to airplanes with a MTOW of 66,000 pounds, the
accident airplane would have been subject to its requirements.\10\
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    \10\ The accident airplane was equipped with an ice detection
system that would enable an operator to comply with this proposed
rule. Preliminary reports indicate that the ice protection system
was operating at the time of the accident.
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E. Phase of Flight Considerations

1. Approach, Landing, Go-Around and Holding Phases of Flight
    The IPHWG accident and incident review revealed that the phases of
flight that presented the greatest risk from airframe icing were those
associated with low speed and relatively high angle-of-attack operation
(that is, approach, landing, go-around, and holding). With respect to
these phases of flight, for airplanes not equipped with primary or
advisory ice detection systems, the IPHWG determined that the following
factors substantiated the need for requiring activation of the airframe
IPS while in conditions conducive to icing:
     An overall majority of events which originated in these
phases of flight;
     A sufficient number of events in which the flightcrew was
confirmed to be unaware of ice accretion, supplemented by a substantial
number of events in which flightcrew awareness of ice accretion was
unknown;
     High cockpit workload resulting in low residual flightcrew
attention;
     Frequent maneuvering, resulting in little opportunity for
the flightcrew to detect aerodynamic degradations due to icing; and
     Maneuvering at relatively high angles of attack.
    The FAA concurred with this analysis.
2. Cruise Phase
    In contrast with the phases of flight discussed previously, for the
cruise phase of flight in airplanes not equipped with primary or
advisory ice detection systems, the IPHWG determined that it would not
be appropriate to require activation of the airframe IPS while in
conditions conducive to icing. Rather, the IPHWG recommended that the
airframe IPS be activated at the first sign of ice accretion, and
operated thereafter, using an automatic system or manually based on
time, until after the airplane departs the conditions conducive to
icing.
    The IPHWG reviewed accidents and incidents that originated during
the cruise phase of flight.\11\ For the events with sufficient data
available for analysis, the IPHWG found that flightcrews were aware of
the ice accretion, but did not activate the IPS. Waiting for a specific
thickness of ice to accrete before activating the IPS was consistent
with the common activation procedure at that time.
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    \11\ Cruise is the phase in which an altitude or flight level is
maintained during en route level flight.
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    Flightcrew workload is lighter during the cruise phase of flight.
This may account for the flightcrews of the cruise phase accident and
incident airplanes being aware of the ice accretion, as compared to
events which have occurred in other phases of flight, when workload was
high and flightcrews were not aware of ice accretions.
    The IPHWG also considered the human factors aspect of requiring

flightcrews to activate the IPS during the cruise phase of flight.
Activation of the IPS based on conditions conducive to ice accretion,
even if ice is not actually accreting, is a conservative way to ensure
that the IPS is operated in a timely manner. For the cruise phase of
flight, however, the IPHWG considered that flightcrews would more
reliably activate the airframe IPS at the first sign of icing than they
would if required to activate the system and keep operating it for long
periods without any indication of ice accretion.
    The IPHWG determined the following factors substantiated the
acceptability of requiring activation of the airframe IPS based on
flightcrew observation of airframe ice accretions during the cruise
phase of flight:
     No accidents or incidents during cruise where the
flightcrew were unaware of ice accretions on the airframe;
     Low cockpit workload, resulting in sufficient residual
flightcrew attention to detect ice accretions;
     Infrequent maneuvering, resulting in opportunity for the
flightcrew to detect aerodynamic degradations due to icing; and
     Human factors concerns about requiring flightcrews to
operate the IPS for extended periods of time when there may not be any
ice on the airframe.
    The FAA agrees with this analysis. Therefore, for the cruise phase
of flight, this proposed rule is written to require IPS activation and
use at the first sign of ice on the airplane and thereafter, according
to the procedures in the AFM or in the manual required by Sec.
121.133. This may be accomplished with an automatic system, or the IPS
may be cycled manually based on time.
3. Takeoff Phase of Flight
    The IPHWG excluded the takeoff phase of flight from its
recommendation for rulemaking because the accidents related to that
phase of flight were caused by improper ground deicing/anti-icing
procedures. Ground deicing and anti-icing procedures have been
addressed by Amendment 121-253 to 14 CFR (121.629(b) and (c),
``Operating in icing conditions''). Again, the FAA agreed with this
recommendation.

F. Temperature

    In some cases, airframe manufacturers have specified definitions of
icing conditions for some airplane types. In the absence of type-
specific information, the IPHWG concluded that conditions conducive to
airframe icing would exist in flight at an outside air temperature at
or below 2 [deg]C in clouds or precipitation.
    Engine IPSs are commonly operated at or below a static air
temperature of 5 [deg]C or a total air temperature of 10 [deg]C. This
temperature is different from the 2 [deg]C recommended by ARAC for this
proposal. The FAA believes that using a common temperature for
activation of both the engine and the airframe IPSs would reduce crew
workload and decrease the probability of the flightcrew not noticing
when the temperature has dropped to 2 [deg]C. The FAA therefore
proposes to identify conditions conducive to airframe icing in this
proposed rule as visible moisture at or below a static air temperature
of 5 [deg]C or a total air temperature of 10 [deg]C.
    The FAA agrees with the IPHWG that flightcrews must be given a
clear means to know when to activate the airframe IPS. In the past,
many airplanes have had procedures requiring activation only after a
substantial accumulation of ice. This proposed rule would require that
ice detection systems be installed, or that ice protection systems be
manually activated in conditions conducive to icing in most phases of
flight. In the cruise phase, the airframe IPS would be activated at the
first sign of ice accumulation anywhere on the airplane. To ensure
timely activation of the airframe IPS, the FAA proposes to amend the
current part 121 regulations as recommended by the IPHWG, except for
the change to the temperature considered conducive to airframe icing,
as discussed above.

G. Technology Available To Comply With Proposed Rule

    The FAA and IPHWG reviewed the current state of ice detector
technology and found viable means of compliance with the proposed rule.
There are several methods available to reliably alert the flightcrew to
activate the airframe IPS. This technology has been approved for use on
airplanes to alert or advise the pilot of ice accretion, or as the
primary means of determining when the airframe IPS should be activated.

H. Differences From the ARAC Recommendation

    Besides the change in the air temperatures proposed for defining
conditions conducive to icing, which is discussed earlier in this
document, the FAA made several other changes to the rule recommended by
ARAC through the IPHWG. One change was a rewording of the ARAC-
recommended rule to clarify its applicability to the airframe IPS. The
rule language recommended by ARAC did not specify applicability only to
airframe IPSs.
    The FAA made another change because, although the ARAC
recommendation provided three ways to ensure that the flightcrew would
know when to activate the airframe IPS, for at least one of them it did
not specify when the flightcrew must activate the airframe IPS. The
agency has revised the ARAC wording to clarify when the flightcrew must
activate the airframe IPS. The FAA also revised the ARAC-recommended
rule to specify items that must be included in the AFM or the manual
required by Sec.  121.133. These revisions are considered minor changes
to the ARAC's recommendation.

I. Airworthiness Directives

    The requirements proposed in this NPRM to some extent overlap and
duplicate existing requirements in certain airworthiness directives
(ADs). As discussed above, these ADs require revisions to the AFM for
certain airplanes to provide information and instructions to pilots for
operating in icing conditions. This proposed rule would also require
AFM revisions to provide information for operating in icing conditions
for those same airplanes, among others. However, the operating
information required by this proposal would be more detailed and
specific to the individual airplane models than the information
required by the ADs and, in some cases, the proposed instructions to
the pilots would be more stringent than those required by the ADs.
    If this proposed rule is adopted, the FAA will revise those ADs to
incorporate the new requirements. It is necessary to retain those ADs
because this proposed rule would apply only to part 121 operations. The
ADs, on the other hand, apply to all operations of the subject
airplanes. Rescinding the ADs would allow reintroduction of the unsafe
condition (that is, delayed activation of IPSs) into operations
conducted under other parts.
    The list of those ADs appears in Appendix 2 of the preamble of this
NPRM.

J. Level of Approval

    For an amended or supplemental type certificate used to comply with
this proposed rule, among the pertinent rules that apply to any
modification are Sec. Sec.  23.1301 or 25.1301 (``Equipment--Function
and installation''). Paragraph (a) of these rules requires that the
equipment ``be of a kind and design appropriate to its intended
function.'' This proposed rule would not by itself impose new
airworthiness standards. However, to meet this ``intended function''
requirement, an applicant seeking approval of design changes to enable
operators to comply with this

proposed rule would have to show that the airplane, as modified, would,
in fact, comply with this proposed rule. This requirement is consistent
with the FAA's practice of compliance findings for the digital flight
data recorder requirements of Sec.  121.343 (Amendment No. 121-238,
``Extension of Compliance Data for Installation of Digital Flight Data
Recorders on Stage 2 Airplanes'').\12\
---------------------------------------------------------------------------

    \12\ Docket No. 27532, published in the Federal Register on May
24, 1994 (59 FR 26896).
---------------------------------------------------------------------------

    This proposed rule is not intended to disapprove an existing part
23 or part 25 approval for flight in icing conditions. It would not
require re-certification of an airplane for flight in conditions
conducive to airframe icing.

K. Compliance Time

    This notice proposes a two-year compliance time after the effective
date of the final rule. That compliance time is based on the time
required to approve new designs and install new equipment. For some
airplanes, it may be possible to comply through AFM revisions alone,
which could be accomplished quickly. However, some airplanes may need
to go through a more involved certification process, so the longer
compliance time of two years was chosen.

L. Reasons for Not Proposing Part 91 and Part 135 Operating Rules

    Part 121 covers all scheduled air carrier operations of airplanes
with ten or more passenger seats and scheduled air carrier operations
of all turbojets regardless of size. The ``hub and spoke'' route
network of many air carriers can concentrate large numbers of part 121
operations within a single weather system. With occasional exceptions
under Sec.  121.590, part 121 operators are constrained to using only
airports certificated under 14 CFR part 139. A given part 121 operator
is generally further constrained to use of only those part 139 airports
listed in its Operations Specifications.
    Flightcrews of part 121 operators generally do not carry approach
charts for airports not listed in their Operations Specifications.
During busy traffic periods, lengthy vectoring or holding for landing
sequencing is common at these airports. When this vectoring results in
exposure to undesirable conditions such as icing, the flightcrews'
options (except in case of emergency) are generally limited to
tolerating the exposure or diverting to a pre-planned part 139
alternate airport listed in their Operations Specifications.
    The FAA considered 14 CFR part 91 and part 135 operations. Most
aircraft operated under parts 91 and 135 have been subjected to the ADs
discussed above regarding activation of their de-icing boots at first
signs of ice accretion. Those ADs apply to all aircraft with pneumatic
de-icing boots that are certificated for flight in known icing
conditions. The ADs addressing boot activation resulted from an FAA
review of operating procedures and certification bases on the affected
aircraft. As a result of this aircraft review and issuance of ADs, a
level of safety for initial ice accretions has been established.
    Part 91 and part 135 aircraft are typically smaller-scale aircraft
than those operated under part 121. This smaller scale provides easier
monitoring of ice accretions. Part 91 and part 135 operators are also
not limited to part 139 airports only, and in fact, often avoid them
because of the factors discussed above. Even when such operations
include part 139 airports, operators may divert to any of a number of
suitable airports near the scheduled part 139 airport. Consequently,
part 91 and part 135 operators often operate in a lower air traffic
density that results in fewer holding delays and significantly more
routing options in icing conditions.
    The level of safety provided by the combination of the ADs, the
review of the operating procedures, the ability to more readily
evaluate ice accretions, and tactical flexibility provide a level of
safety comparable to other part 91 and part 135 operational
requirements. The proposed part 121 rule change will enhance the level
of safety for the segment of the traveling public that has the greatest
exposure and subsequent risk associated with flight in icing
conditions. Therefore, the IPHWG concluded that rules for parts 91 and
135 are not required at this time, and the FAA agrees.

M. Applicability to Part 23 and Part 25 Airplanes

    The icing accident and incident database developed by the IPHWG
showed that all the relevant accidents and incidents occurred on
airplanes with a certificated MTOW of less than 60,000 pounds. Based on
this finding, the FAA is proposing a part 121 rule that is applicable
to those airplanes. Since the proposed rule addresses the safety
concerns of flight in icing conditions for smaller airplanes (those
with a certificated MTOW less than 60,000 pounds), the rule would be
applicable to both part 23 and part 25 airplanes that are operated
under part 121.

N. Discussion of Working Group Non-Consensus Issues

    The IPHWG did not reach consensus on several issues related to this
rulemaking proposal. A summary of these issues can be found in the
docket. The complete working group discussion of the dissenting
opinions is also available in the docket for this rulemaking.

O. Related ARAC Recommendations

    The ARAC has submitted the following additional rulemaking
recommendations to the FAA to improve the safety of operations in icing
conditions. The FAA has not yet completed deliberations on these
recommendations, but they may lead to future rulemaking.
     A part 121 recommendation to require certain airplanes to
exit icing conditions.
     Parts 25 and 33 recommendations to address ice protection
activation and operations in supercooled large droplet, mixed phase,
and glaciated icing conditions.

Rulemaking Notices and Analyses

Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires
that the FAA consider the impact of paperwork and other information
collection burdens imposed on the public. The FAA has determined that
there are no new information collection requirements associated with
this proposed rule.

International Compatibility

    In keeping with U.S. obligations under the Convention on
International Civil Aviation, it is FAA policy to comply with
International Civil Aviation Organization (ICAO) Standards and
Recommended Practices to the maximum extent practicable. The FAA
determined that there are no ICAO Standards and Recommended Practices
that correspond to these proposed regulations.

Economic Evaluation, Regulatory Flexibility Determination, Trade Impact
Assessment, and Unfunded Mandates Assessment

    Changes to Federal regulations must undergo several economic
analyses. First, Executive Order 12866 directs that each Federal agency
shall propose or adopt a regulation only upon a reasoned determination
that the benefits of the intended regulation justify its costs. Second,
the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires
agencies to analyze the economic

impact of regulatory changes on small entities. Third, the Trade
Agreements Act (Pub. L. 96-39) prohibits agencies from setting
standards that create unnecessary obstacles to the foreign commerce of
the United States. In developing U.S. standards, this Trade Act
requires agencies to consider international standards and, where
appropriate, that they be the basis of U.S. standards. Fourth, the
Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires agencies
to prepare a written assessment of the costs, benefits, and other
effects of proposed or final rules that include a Federal mandate
likely to result in the expenditure by State, local, or Tribal
governments, in the aggregate, or by the private sector, of $100
million or more annually (adjusted for inflation with base year of
1995). This portion of the preamble summarizes the FAA's analysis of
the economic impacts of this proposed rule. The FAA suggests readers
seeking greater detail read the full regulatory evaluation, a copy of
which the agency has placed in the docket for this rulemaking.
    In conducting these analyses, the FAA has determined that this
proposed rule: (1) Has benefits that justify its costs, (2) is not an
economically ``significant regulatory action'' as defined in section
3(f) of Executive Order 12866, (3) has been designated as a
``significant regulatory action'' by the Office of Management and
Budget, because it harmonizes U.S. and international standards, and is
therefore ``significant'' under DOT's Regulatory Policies and
Procedures; (4) would not have a significant economic impact on a
substantial number of small entities; (5) would not create unnecessary
obstacles to the foreign commerce of the United States; and (6) would
not impose an unfunded mandate on State, local, or Tribal governments,
or on the private sector by exceeding the threshold identified above.
These analyses are summarized below.

Total Benefits and Costs of This Rule

    The estimated cost of this proposed rule is about $5.5 million
($2.9 million in seven percent present value terms). The estimated
potential benefits of averting one accident and four fatalities are
about $17.3 million ($12.6 million in seven percent present value
terms).

Who Is Potentially Affected by This Rule?

    Operators of transport category airplanes with a maximum take-off
weight under 60,000 pounds operating under 14 CFR part 121.

Assumptions

    (1) The base year is 2008.
    (2) The proposal will become final in December 2010.
    (3) The compliance date of the rule is 24 months from the effective
date of the final rule.
    (4) The analysis period is 20 years.
    (5) The value of an averted fatality is $5.8 million.\13\
---------------------------------------------------------------------------

    \13\ ``Treatment of the Economic Value of a Statistical Life in
Departmental Analysis'', February 5, 2008, U.S. Department of
Transportation Memorandum.
---------------------------------------------------------------------------

    (6) The FAA used $79.93 hourly rate for a mechanic/technician
working for an airplane manufacturer or modifier and the $76.01 hourly
rate for an engineer working for an airplane manufacturer or modifier.
These hourly rates include overhead costs.
    (7) The FAA assumed whenever various compliance options are
available to the operators, the minimal cost option will always be
chosen.

Benefits of This Rule

    The benefits of this proposed rule consist of the value of
fatalities, loss of airplanes, and investigation cost averted from
avoiding accidents involving transport category airplanes with a
maximum take-off weight under 60,000 pounds operating under 14 CFR part
121. The FAA estimates that one accident and four fatalities could
potentially be avoided, over the analysis period, by adopting the
proposed rule. The value of an averted fatality is assumed to be $5.8
million. A series of airworthiness directives (AD) were issued for
airplanes with pneumatic de-icing boots to activate the systems at the
first sign of ice accretion. Due to the similarity of requirements
between the ADs and this proposal, the FAA accounted for the effects of
recent ADs by reducing the estimated benefits. Over the analysis
period, the potential benefits of the proposed rule would be $17.3
million ($12.6 million in seven percent present value terms).

Estimated Costs of This Proposal

    Using Ice Protection Harmonization Working Group (IPHWG) airplane
compliance costs, the FAA estimates the total undiscounted cost of the
proposed rule, over the analysis period, to be about $5.5 million. The
seven percent present value cost of this proposed rule over the
analysis period is about $2.9 million. The agency estimates the initial
costs for a new certification program to operate the deicing boots
based on visible moisture and temperature are about $385,000. The FAA
estimates the operating and training costs are about $5.1 million.

Alternatives Considered

Alternative One
    The alternative of maintaining the status quo would not address the
NTSB recommendations and the FAA's In-flight Icing Plan. The FAA
rejected this alternative because the proposed rule would enhance
passenger safety and prevent icing-related accidents for airplanes with
a certificated MTOW less than 60,000 pounds. As it stands, the proposed
rule is the reasoned result of the FAA Administrator carrying out the
FAA's In-flight Aircraft Icing Plan.
Alternative Two
    Alternative Two would be to issue more ADs requiring a means to
know when to activate the airframe IPS. The FAA has already issued ADs
to address the activation of airframe IPSs.
    An evaluation of accidents and incidents led to the conclusion that
the ADs do not provide adequate assurance that the flightcrew will be
made aware of when to activate the airframe IPS. Because this problem
is not unique to particular airplane designs, but exists for all
airplanes that are susceptible to the icing hazards described
previously, it is appropriate to address this problem through an
operational rule, rather than by ADs.
Alternative Three
    Alternative Three is the proposed rule. The FAA's judgment is that
this is the most viable option, since the proposed rule will increase
the safety of the flying public by reducing icing-related accidents in
the future in the least costly way.

Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA)
establishes ``as a principle of regulatory issuance that agencies shall
endeavor, consistent with the objectives of the rule and of applicable
statutes, to fit regulatory and informational requirements to the scale
of the businesses, organizations, and governmental jurisdictions
subject to regulation. To achieve this principle, agencies are required
to solicit and consider flexible regulatory proposals and to explain
the rationale for their actions to assure that such proposals are given
serious consideration.'' The RFA covers a wide range of small entities,
including small businesses, not-for-profit organizations, and small
governmental jurisdictions.
    Agencies must perform a review to determine whether a rule will
have a significant economic impact on a substantial number of small
entities. If the agency determines that it will, the

agency must prepare a regulatory flexibility analysis as described in
the RFA.
    However, if an agency determines that a rule is not expected to
have a significant economic impact on a substantial number of small
entities, section 605(b) of the RFA provides that the head of the
agency may so certify and a regulatory flexibility analysis is not
required. The certification must include a statement providing the
factual basis for this determination, and the reasoning should be
clear.
    The FAA believes that this proposed rule would not have a
significant impact on a substantial number of small entities for the
following reasons.
    On October 31, 1994, at 1559 Central Standard Time, an Avions de
Transport Regional Model ATR 72, operated by Simmons Airlines,
Incorporated, and doing business as American Eagle flight 4184, crashed
during a rapid descent after an uncommanded roll excursion. The FAA,
Aerospatiale, the French Direction G[eacute]n[eacute]rale de l'Aviation
Civile, Bureau Enquete Accident, National Aeronautics and Space
Administration (NASA), National Transportation Safety Board, and others
have conducted an extensive investigation of this accident.
    This accident and the investigation prompted the FAA to initiate a
review of aircraft in-flight icing safety and determine changes that
could be made to increase the level of safety. The proposed rule
addresses NTSB recommendation A-07-14. The proposed rule is also one of
the items listed in the FAA's In-flight Aircraft Icing Plan, April
1997. The Icing Plan details the FAA's plans for improving the safety
of airplanes when they are operated in icing conditions.
    This NPRM specifically applies to 14 CFR part 121 operators of
airplanes that have a certificated MTOW of less than 60,000 pounds. The
FAA determined which small entities could be affected by associating
airplanes with a certificated MTOW of less than 60,000 pounds with part
121 operators. For this section of the analysis, the agency considered
only those operators meeting the above criteria that have 1,500 or
fewer employees.
    To estimate the number of affected airplanes, the FAA analyzed the
current active fleet of airplanes, a forecast of airplanes affected by
the proposed rule entering the fleet, and a forecast of the retired
affected airplanes exiting the fleet during the analysis period.
    The FAA also generated a list of all U.S. operated civilian
airplanes operating under 14 CFR part 121. Each airplane group was
matched with its current (as of September 2008) MTOW and average age
through the use of the BACK FleetPCTM database. All airplanes with an
MTOW greater than 60,000 pounds were eliminated.
    Using industry sources, the FAA determined which airplanes
currently had primary or advisory icing detection systems. Airplanes
equipped with either a primary or advisory ice detection systems are in
compliance, and this proposal would impose no costs to operators of
these airplanes. All turbojets affected by this proposal are in
compliance, as these airplanes are equipped with either an approved
primary ice detection system or advisory ice detection systems.
    For the base case, the FAA used the FAA Aerospace Forecast, 2008-
2025 (Table 26) for the part 121 regional turboprop retirement forecast
and determined the number of turboprop airplanes that would retire over
the analysis interval. The report does not forecast turboprop airplanes
by equipment type. In estimating the costs, the FAA retires the older
active airplanes affected by the proposal first.
    Using information provided by the World Aviation Directory, SEC
filings, and the Internet, scheduled and non-scheduled commercial
operators that are subsidiary businesses of larger businesses were
eliminated from the database. An example of a subsidiary business is
Continental Express, Inc., which is a subsidiary of Continental
Airlines. Using information provided by the U.S. Department of
Transportation Form 41 filings, the World Aviation Directory, Winter
2000, and Dunn and Bradstreet's company databases, all businesses with
more than 1,500 employees were eliminated. For the remaining
businesses, the FAA obtained company revenue from these sources when
the operator's revenue was public. Following this approach, six small
entities operate airplanes that would be affected by this proposal.
    The FAA estimated the cost of compliance per airplane and
multiplied this cost by the total fleet of affected airplanes per
operator, over the analysis period, to obtain the total compliance cost
by small entity. The non-recurring costs, for updating the AFM for each
major airplane group, were distributed equally among the airplanes in
each major airplane group. These non-recurring costs occurred in year
four of the analysis period. Note the more airplanes in a major
airplane group, the less expensive, per airplane, the non-recurring
costs are to the operators of those airplanes. In addition to the AFM
cost, the additional incremental recurring costs include boot
maintenance, replacement, and installation labor. These recurring costs
started in year five and continued either until the airplane retired or
through the end of the analysis period.
    The degree to which small air operator entities can ``afford'' the
cost of compliance is determined by the availability of financial
resources. The initial implementation costs of the proposed rule may be
financed, paid for using existing company assets, or borrowed. As a
proxy for the firm's ability to afford the cost of compliance, the FAA
calculated the ratio of the total annualized cost of the proposed rule
as a percentage of annual revenue. This ratio is a conservative measure
as the annualized value of the 20-year total compliance cost is divided
by one year of annual revenue (no growth in revenues is assumed). No
small business operator potentially affected by this proposed rule
incurred costs greater that one percent of their annual revenue. The
following table shows the base case economic impact on the small entity
air operators affected by this proposed rule.

                                              Table 1--Economic Impact on Small Entity Operators--Base Case
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Small operator  Small operator  Small operator  Small operator  Small operator  Small operator
                          Year                                   A               B               C               D               E               F
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.......................................................              $0              $0              $0              $0              $0              $0
2.......................................................               0               0               0               0               0               0
3.......................................................               0               0               0               0               0               0
4.......................................................          59,717         302,084         302,084          37,540          15,591          92,992
5.......................................................          58,617          87,925          87,925           7,327               0          29,308
6.......................................................          58,617          73,271          80,598           7,327               0          29,308
7.......................................................          58,617          65,944          65,944               0               0          21,981
8.......................................................          58,617          51,290          51,290               0               0          14,654

9.......................................................          58,617          36,636          36,636               0               0           7,327
10......................................................          58,617          29,308          29,308               0               0               0
11......................................................          58,617          21,981          21,981               0               0               0
12......................................................          58,617          14,654          14,654               0               0               0
13......................................................          58,617           7,327          14,654               0               0               0
14......................................................          58,617           7,327           7,327               0               0               0
15......................................................          58,617               0           7,327               0               0               0
16......................................................          58,617               0           7,327               0               0               0
17......................................................          58,617               0               0               0               0               0
18......................................................          51,290               0               0               0               0               0
19......................................................          43,963               0               0               0               0               0
20......................................................          36,636               0               0               0               0               0
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................         953,623         697,748         727,056          52,194          15,591         195,571
                                                         ===============================================================================================
Annualized Costs........................................          90,012          65,860          68,627           4,927           1,472          18,460
Annual Revenue..........................................      30,000,000      76,348,000     100,000,000      78,148,212     141,000,000      18,200,000
Percentage..............................................           0.30%           0.09%           0.07%           0.01%           0.00%           0.10%
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The FAA conducted a sensitivity analysis \14\ where the agency
relaxed the retirement assumption from the base case. For this
sensitivity analysis, the FAA used the FleetPCTM database and
determined turboprops are retired from U.S. certificated service at an
average age (mean) of 26.4. In the base case, the FAA assumes the
active affected airplanes start retiring in year one and continue to
retire at the annual turboprop retirement rate estimated by the FAA
forecasting group.\15\ In the sensitivity analysis, the agency assumes
each of the small operator's airplanes are retired when the average age
for the fleet of this airplane type reaches the average retirement age
of 26.4 years. For all but one operator, the sensitivity analysis
results in slightly higher costs. The following table shows the results
of the sensitivity analysis the FAA performed for the economic impact
on the small entity air operators affected by this proposed rule.
---------------------------------------------------------------------------

    \14\ A sensitivity analysis is the study of how the variation
(uncertainty) in the output of a mathematical model can be
apportioned, qualitatively or quantitatively, to different sources
of variation in the input of a model.
    \15\ FAA Statistical and Forecast Branch, APO-110--FAA Aerospace
Forecast, 2008-2025, Table 26.

                    Table 2--Sensitivity Analysis Economic Impact on Small Entity Operators When Airplanes Are Retired at 26.4 Years
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Small operator  Small operator  Small operator  Small operator  Small operator  Small operator
                          Year                                   A               B               C               D               E               F
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.......................................................              $0              $0              $0              $0              $0              $0
2.......................................................               0               0               0               0               0               0
3.......................................................               0               0               0               0               0               0
4.......................................................          59,494         338,163         338,163          62,623          37,573         112,716
5.......................................................          58,617         197,832         197,832          36,636          21,981          65,944
6.......................................................          58,617         197,832         197,832          36,636          21,981          65,944
7.......................................................          58,617         197,832         197,832          36,636               0          65,944
8.......................................................          58,617         197,832         197,832          36,636               0          65,944
9.......................................................          58,617         197,832         197,832          36,636               0          65,944
10......................................................          58,617               0               0               0               0               0
11......................................................               0               0               0               0               0               0
12......................................................               0               0               0               0               0               0
13......................................................               0               0               0               0               0               0
14......................................................               0               0               0               0               0               0
15......................................................               0               0               0               0               0               0
16......................................................               0               0               0               0               0               0
17......................................................               0               0               0               0               0               0
18......................................................               0               0               0               0               0               0
19......................................................               0               0               0               0               0               0
20......................................................               0               0               0               0               0               0
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................         411,195       1,327,321       1,327,321         245,800          81,536         442,435
                                                         ===============================================================================================
Annualized Costs........................................          38,813         125,286         125,286          23,201           7,696          41,761
Annual Revenue..........................................      30,000,000      76,348,000     100,000,000      78,148,212     141,000,000      18,200,000
Percentage..............................................           0.13%           0.16%           0.13%           0.03%           0.01%           0.23%
--------------------------------------------------------------------------------------------------------------------------------------------------------

    For both the base case and sensitivity analysis retirement model
scenarios, the FAA calculated no small business operator potentially
affected by this proposed rule would incur costs greater than one
percent of their annual revenue. Therefore the FAA certifies that this
proposed rule would not have a significant economic impact on a
substantial number of small entities. The FAA solicits comments
regarding this determination.

International Trade Impact Analysis

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal
agencies from establishing standards or engaging in related activities
that create unnecessary obstacles to the foreign commerce of the United
States. Pursuant to these Acts, the establishment of standards is not
considered an unnecessary obstacle to the foreign commerce of the
United States, so long as the standard has a legitimate domestic
objective, such as the protection of safety, and does not operate in a
manner that excludes imports that meet this objective. The statute also
requires consideration of international standards and, where
appropriate, that they be the basis for U.S. standards. The FAA notes
the purpose is to ensure the safety of the American public, and has
assessed the effects of this proposed rule to ensure it does not
exclude imports that meet this objective. As a result, this proposed
rule is not considered as creating an unnecessary obstacle to foreign
commerce. It has been determined that this proposed rule would respond
to a domestic safety objective and is not considered an unnecessary
obstacle to trade.

Unfunded Mandates Assessment

    Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement
assessing the effects of any Federal mandate in a proposed or final
agency rule that may result in an expenditure of $100 million or more
(in 1995 dollars) in any one year by State, local, and Tribal
governments, in the aggregate, or by the private sector; such a mandate
is deemed to be a ``significant regulatory action.'' The FAA currently
uses an inflation-adjusted value of $136.1 million in lieu of $100
million. This proposed rule does not contain such a mandate; therefore,
the requirements of Title II of the Act do not apply.

Executive Order 13132, Federalism

    The FAA has analyzed this proposed rule under the principles and
criteria of Executive Order 13132, Federalism. The agency determined
that this action would not have a substantial direct effect on the
States, on the relationship between the national Government and the
States, or on the distribution of power and responsibilities among the
various levels of government, and therefore would not have federalism
implications.

Regulations Affecting Intrastate Aviation in Alaska

    Section 1205 of the FAA Reauthorization Act of 1996 (110 Stat.
3213) requires the Administrator, when modifying regulations in Title
14 of the CFR in a manner affecting intrastate aviation in Alaska, to
consider the extent to which Alaska is not served by transportation
modes other than aviation, and to establish appropriate regulatory
distinctions. Because this proposed rule would apply to airplanes
operating in Alaska, it could, if adopted, affect intrastate aviation
in Alaska. The FAA, therefore, specifically requests comments on
whether there is justification for applying the proposed rule
differently in intrastate operations in Alaska.

Environmental Analysis

    FAA Order 1050.1E identifies FAA actions that are categorically
excluded from preparation of an environmental assessment or
environmental impact statement under the National Environmental Policy
Act in the absence of extraordinary circumstances. The FAA has
determined that this proposed rulemaking action qualifies for the
categorical exclusion identified in paragraph 4(j) and involves no
extraordinary circumstances.

Regulations That Significantly Affect Energy Supply, Distribution, or
Use

    The FAA has analyzed this NPRM under Executive Order 13211, Actions
Concerning Regulations that Significantly Affect Energy Supply,
Distribution, or Use (May 18, 2001). The agency has determined that it
is not a ``significant energy action'' under the executive order
because, while it is defined as ``significant'' under DOT's Regulatory
Policies and Procedures Executive Order 12866 because it harmonizes
U.S. aviation standards with those of other civil aviation authorities,
it is not likely to have a significant adverse effect on the supply,
distribution, or use of energy.

Plain English

    Executive Order 12866 (58 FR 51735, Oct. 4, 1993) requires each
agency to write regulations that are simple and easy to understand. The
FAA invites your comments on how to make these proposed regulations
easier to understand, including answers to questions such as the
following:
     Are the requirements in the proposed regulations clearly
stated?
     Do the proposed regulations contain unnecessary technical
language or jargon that interferes with their clarity?
     Would the proposed regulations be easier to understand if
they were divided into more (but shorter) sections?
     Is the description in the preamble helpful in
understanding the proposed regulations?
    Please send your comments to the address specified in the ADDRESSES
section of this preamble.

Additional Information

Comments Invited
    The FAA invites interested persons to participate in this
rulemaking by submitting written comments, data, or views. The agency
also invites comments relating to the economic, environmental, energy,
or federalism impacts that might result from adopting the proposals in
this document. The most helpful comments reference a specific portion
of the proposal, explain the reason for any recommended change, and
include supporting data. To ensure the docket does not contain
duplicate comments, please send only one copy of written comments, or
if you are filing comments electronically, please submit your comments
only one time.
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report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal,
the agency will consider all comments received on or before the closing
date for comments. The FAA will consider comments filed after the
comment period has closed if it is possible to do so without incurring
expense or delay. The agency may change this proposal in light of the
comments received.
Proprietary or Confidential Business Information
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information directly to the person identified in the FOR FURTHER
INFORMATION CONTACT section of this document. You must mark the

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specific information that is proprietary or confidential.
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of this rulemaking.
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paragraph (1).

Appendix 1 of the Preamble

Definition of Terms Used in the Preamble of This NPRM

    For purposes of the preamble of this NPRM, the following
definitions are applicable.
    a. Advisory ice detection system--A system that advises the
flightcrew of the presence of ice accretion or icing conditions.
Both primary ice detection systems and advisory ice detection
systems can either direct the pilot to manually activate the IPS or
provide a signal that automatically activates the IPS. However,
because it has lower reliability than a primary system, an advisory
ice detection system can only be used in conjunction with other
means (most commonly, visual observation by the flightcrew) to
determine the need for, or timing of, activating the anti-icing or
deicing system. With an advisory ice detection system, the
flightcrew is responsible for monitoring icing conditions or ice
accretion as defined in the Airplane Flight Manual (AFM), typically
using total air temperature and visible moisture criteria or visible
ice accretion. With an advisory ice detection system, the flightcrew
is responsible for activating the anti-icing or deicing system(s).
    b. Airframe icing--Ice accretion on the airplane, except for on
the propulsion system.
    c. Anti-icing--Prevention of ice accretions on a protected
surface, either by:
     Evaporating the impinging water, or
     Allowing the impinging water to run back and off the
protected surface or freeze on non-critical areas.
    d. Automatic cycling mode--A mode of operation of the airframe
de-icing system that provides repetitive cycles of the system
without the need for the pilot to select each cycle. This is
generally done with a timer, and there may be more than one timing
mode.
    e. Conditions conducive to airframe icing--Visible moisture at
or below a static air temperature of 5 [deg]C or total air
temperature of 10 [deg]C, unless the approved Airplane Flight Manual
provides another definition.
    f. Deicing--The removal or the process of removal of an ice
accretion after it has formed on a surface.
    g. Ice protection system (IPS)--A system that protects certain
critical aircraft parts from ice accretion. To be an approved
system, it must satisfy the requirements of Sec.  23.1419 or Sec.
25.1419 and other applicable requirements.
    h. Primary ice detection system--A detection system used to
determine when the IPS must be activated. This system announces the
presence of ice accretion or icing conditions, and it may also
provide information to other aircraft systems. A primary automatic
system automatically activates the anti-icing or deicing IPS. A
primary manual system requires the flightcrew to activate the anti-
icing or deicing IPS upon indication from the primary ice detection
system.
    i. Reference surface--The observed surface used as a reference
for the presence of ice on the monitored surface. The reference
surface may be observed directly or indirectly. Ice must occur on
the reference surface before--or at the same time as--it appears on
the monitored surface. Examples of reference surfaces include
windshield wiper blades or bolts, windshield posts, ice evidence
probes, the propeller spinner, and the surface of ice detectors. The
reference surface may also be the monitored surface.
    j. Static air temperature--The air temperature that would be
measured by a temperature sensor that is not in motion in relation
to that air. This temperature is also referred to in other documents
as ``outside air temperature,'' ``true outside temperature,'' or
``ambient temperature.''
    k. Total air temperature--The static air temperature plus the
rise in temperature due to the air being brought to rest relative to
the airplane.
    l. Visual cues--Ice accretion on a reference surface that the
flightcrew observes. The visual cue is used to detect the first sign
of airframe ice accretion.

Appendix 2 of the Preamble

                     Airworthiness Directives (AD) Addressing Operations in Icing Conditions
----------------------------------------------------------------------------------------------------------------
          Airplane model                             Docket No.                           Final Rule No.
----------------------------------------------------------------------------------------------------------------
Industrie Aeronautiche e           99-CE-34-AD..................................  2000-03-19 REM.
 Meccaniche, Model Piaggio P-180
 Airplanes.
Pilatus Britten-Norman Ltd., BN-   99-CE-35-AD..................................  Withdrawn.
 2T Series Airplanes.
Pilatus Aircraft Ltd., Models PC-  99-CE-36-AD..................................  2000-11-14.
 12 and PC-12/45 Airplanes.
Partenavia Costruzioni             99-CE-37-AD..................................  2000-03-18.
 Aeronauticas, S.p.A., Models
 AP68TP 300 ``Spartacus'' and
 AP68TP 600 ``Viator'' Airplanes.
Mitsubishi Heavy Industries,       99-CE-38-AD..................................  2000-02-25.
 Ltd., MU-2B Series Airplanes.
LET, a.s., Model L-420 Airplanes.  99-CE-39-AD..................................  Withdrawn.
British Aerospace, Jetstream       99-CE-40-AD..................................  Withdrawn.
 Models 3101 and 3201 Airplanes.
Harbin Aircraft Manufacturing      99-CE-41-AD..................................  2000-02-26.
 Corp., Model Y12 IV airplanes.
Empresa Brasileira de Aeronautica  99-CE-42-AD..................................  2000-02-27.
 S.A. Airplanes (Embraer) Models
 EMB-110P1 and EMB-110P2
 Airplanes.
Dornier Luftfahrt GmbH, 228        99-CE-43-AD..................................  2000-06-02.
 Series Airplanes.
Bombardier Inc., DHC-6 Series      99-CE-44-AD..................................  2000-06-3.
 Airplanes.
The Cessna Aircraft Company, 208   99-CE-45-AD..................................  Withdrawn.
 Series.
Raytheon Aircraft Company 90, 99,  99-CE-46-AD..................................  Withdrawn.
 100, 200, 300, 1900, and 2000
 Series Airplanes.
AeroSpace Technologies of          99-CE-47-AD..................................  2000-02-28.
 Australia Pty Ltd., Models N22B
 and N24A.
Short Brothers & Harland Ltd.,     99-CE-48-AD..................................  Withdrawn.
 Models SC-7 Series 2 and SC-7
 Series 3 Airplanes.
The New Piper Aircraft, Inc., PA-  99-CE-49-AD..................................  2000-06-06.
 31 Series Airplanes.

The New Piper Aircraft, Inc. PA-   2000-CE-20-AD................................  2000-14-08.
 42 Series Airplanes.
SOCATA--Groupe AEROSPATIALE,       99-CE-50-AD..................................  2000-02-29.
 Model TBM 700 Airplanes.
Twin Commander Aircraft            99-CE-51-AD..................................  2000-02-30.
 Corporation, 600 Series
 Airplanes.
Fairchild Aircraft Corporation,    99-CE-52-AD..................................  2000-06-04.
 SA226 and SA227 Series Airplanes.
The Cessna Aircraft Company,       99-CE-53-AD..................................  Withdrawn.
 Models 425 and 441 Airplanes.
Cessna Aircraft Company, Models    99-NM-136-AD.................................  Withdrawn.
 500, 550, and 560 Airplanes.
Sabreliner Corporation, Models     99-NM-137-AD.................................  99-19-03.
 40, 60, 70, and 80 Series
 Airplanes.
Gulfstream Aerospace, Model G-159  99-NM-138-AD.................................  2000-10-11.
 Series Airplanes.
McDonnell Douglas Models DC-3 and  99-NM-139-AD.................................  2000-04-03.
 DC-4 Series Airplanes.
Mitsubishi Heavy Industries,       99-NM-140-AD.................................  99-19-06.
 Model YS-11 and YS-11A Series
 Airplanes.
Frakes Aviation, Model, G-73       99-NM-141-AD.................................  99-19-07.
 (Mallard) and G-73T Series
 Airplanes.
Lockheed, Models L-14 and L-18     99-NM-142-AD.................................  99-19-08.
 Series Airplanes.
Fairchild Models F27 and FH227     99-NM-143-AD.................................  99-19-09.
 Series Airplanes.
Aerospatiale Models ATR-42/ATR-72  99-NM-144-AD.................................  99-19-10.
 Series Airplanes.
Jetstream Model BAe ATP Airplanes  99-NM-145-AD.................................  99-19-11.
Jetstream Model 4101 Airplanes...  99-NM-146-AD.................................  Withdrawn.
British Aerospace Model HS 748     99-NM-147-AD.................................  99-19-13.
 Series Airplanes.
Saab Model SF340A/SAAB 340B/SAAB   99-NM-148-AD.................................  99-19-14.
 2000 Series Airplanes.
CASA Model C-212/CN-235 Series     99-NM-149-AD.................................  99-19-15.
 Airplanes.
Dornier Model 328-100 Series       99-NM-150-AD.................................  99-19-16.
 Airplanes.
Lockheed Model 1329-23 and 1329-   99-NM-151-AD.................................  99-19-17.
 25 (Lockheed Jetstar) Series
 Airplanes.
de Havilland Model DHC-7/DHC-8     99-NM-152-AD.................................  99-19-18.
 Series Airplanes.
Fokker Model F27 Mark 100/200/300/ 99-NM-153-AD.................................  99-19-19.
 400/500/600/700/050 Series
 Airplanes.
Short Brothers Model SD3-30/SD3-   99-NM-154-AD.................................  99-19-20.
 60/SD3-SHERPA Series Airplanes.
Empresa Brasileira de              97-NM-46-AD..................................  97-26-06.
 Aeronautica, S.A., (EMBRAER)
 Model EMB-120 Series Airplanes.
----------------------------------------------------------------------------------------------------------------
Notes
1. CE in the docket number indicates Part 23 airplanes. NM indicates Part 25 airplanes.
2. Some final rules were withdrawn based on data submitted by the manufacturers. The rationale for withdrawal
  can be found in the dockets.

List of Subjects in 14 CFR Part 121

    Air carriers, Aircraft, Aviation safety, Safety, Transportation.

The Proposed Amendment

    In consideration of the foregoing, the Federal Aviation
Administration proposes to amend part 121 of Title 14, Code of Federal
Regulations, as follows:

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL
OPERATIONS

    1. The authority citation for part 121 continues to read as
follows:

    Authority: 49 U.S.C. 106(g), 40113, 40119, 44101, 44701-44702,
44705, 44709-44711, 44713, 44716-44717, 44722, 44901, 44903-44904,
44912, 46105.

    2. Add Sec.  121.321 to read as follows:

Sec.  121.321  Operations in icing.

    After [a date 24 months after the effective date of the final
rule], no person may operate an airplane with a certificated maximum
takeoff weight less than 60,000 pounds in conditions conducive to
airframe icing unless it complies with this section. As used in this
section, the phrase ``conditions conducive to airframe icing'' means
visible moisture at or below a static air temperature of 5 [deg]C or a
total air temperature of 10 [deg]C, unless the approved Airplane Flight
Manual provides another definition.
    (a) When operating in conditions conducive to airframe icing,
compliance must be shown with paragraph (a)(1), or (a)(2), or (a)(3) of
this section.
    (1) The airplane must be equipped with a certificated primary
airframe ice detection system.
    (i) The airframe ice protection system must be activated
automatically, or manually by the flightcrew, when the primary ice
detection system indicates activation is necessary.
    (ii) When the airframe ice protection system is activated, any
other procedures in the Airplane Flight Manual for operating in icing
conditions must be initiated.
    (2) Visual cues of the first sign of ice formation anywhere on the
airplane and a certificated advisory airframe ice detection system must
be provided.
    (i) The airframe ice protection system must be activated when any
of the visual cues are observed or when the advisory airframe ice
detection system indicates activation is necessary; whichever occurs
first.
    (ii) When the airframe ice protection system is activated, any
other procedures in the Airplane Flight Manual for operating in icing
conditions must be initiated.
    (3) If the airplane is not equipped to comply with the provisions
of paragraph (a)(1) or (a)(2) of this section, then the following
apply:
    (i) When operating in conditions conducive to airframe icing, the
airframe ice protection system must be activated prior to, and operated
during, the following phases of flight:
    (A) Takeoff climb after second segment,
    (B) En route climb,
    (C) Go-around climb,
    (D) Holding,
    (E) Maneuvering for approach and landing, and
    (F) Any other operation at approach or holding airspeeds.
    (ii) During any other phase of flight, the airframe ice protection
system must be activated and operated at the first sign of ice
formation anywhere on the airplane, unless the Airplane Flight Manual
specifies that the airframe ice protection system should not be used or
provides other operational instructions.
    (iii) Any additional procedures for operation in conditions
conducive to icing specified in the Airplane Flight Manual or in the
manual required by Sec.  121.133 must be initiated.
    (b) If the procedures specified in paragraph (a)(3)(i) of this
section are specifically prohibited in the Airplane Flight Manual,
compliance must be shown with the requirements of paragraph (a)(1) or
(a)(2) of this section.
    (c) Procedures necessary for safe operation of the airframe ice
protection system must be established and documented in:

    (1) The Airplane Flight Manual for airplanes that comply with
paragraph (a)(1) or (a)(2) of this section, or
    (2) The Airplane Flight Manual or in the manual required by Sec.
121.133 for airplanes that comply with paragraph (a)(3) of this
section.
    (d) Procedures for operation of the airframe ice protection system
must include initial activation, operation after initial activation,
and deactivation. Procedures for operation after initial activation of
the ice protection system must address--
    (1) Continuous operation,
    (2) Automatic cycling,
    (3) Manual cycling if the airplane is equipped with an ice
detection system that alerts the flightcrew each time the ice
protection system must be cycled, or
    (4) Manual cycling based on a time interval if the airplane type is
not equipped with features necessary to implement paragraphs (d)(1)
through (3) of this section.
    (e) System installations used to comply with paragraphs (a)(1) or
(a)(2) of this section must be approved through an amended or
supplemental type certificate in accordance with part 21 of this
chapter.

    Issued in Washington, DC, on November 16, 2009.
John W. McGraw,
Acting Director, Flight Standards Service.
[FR Doc. E9-28036 Filed 11-20-09; 8:45 am]

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