Document ID: FAA-2012-1207-0001
Agency: faa
Document Type: Proposed Rule
Title: Special Conditions: Airbus, A350-900 Series Airplane; Flight Envelope Protection (Icing and Non-icing conditions); High Incidence Protection and Alpha-floor Systems
Posted Date: 2012-12-19T05:00Z

[Federal Register Volume 77, Number 244 (Wednesday, December 19, 2012)]
[Proposed Rules]
[Pages 75066-75071]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-30441]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2012-1207; Notice No. 25-12-09-SC]

Special Conditions: Airbus, A350-900 Series Airplane; Flight 
Envelope Protection (Icing and Non-Icing Conditions); High Incidence 
Protection and Alpha-Floor Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This action proposes special conditions for Airbus A350-900 
series airplanes. These airplanes will have novel or unusual design 
features associated with flight envelope protection in icing and non-
icing conditions that use low speed incidence protection and an alpha-
floor function that automatically advances throttles whenever the 
airplane angle of attack reaches a predetermined value. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for this design feature. These proposed special conditions 
contain the additional safety standards that the Administrator 
considers necessary to establish a level of safety equivalent to that 
established by the existing airworthiness standards.

DATES: Send your comments on or before February 4, 2013.

ADDRESSES: Send comments identified by docket number FAA-2012-1207 
using any of the following methods:
     Federal eRegulations 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 (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery of Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 8 a.m., and 5 p.m., 
Monday through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://regulations.gov, including any personal information 
the commenter provides. Using the search function of the docket Web 
site, anyone can find and read the electronic form of all comments 
received into any FAA docket, including the name of the individual 
sending the comment (or signing the comment for an association, 
business, labor union, etc.). DOT's complete Privacy Act Statement can 
be found in the Federal Register published on April 11, 2000 (65 FR 
19477-19478), as well as at http://DocketsInfo.dot.gov.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or go to the 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.

FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Airframe and 
Flightcrew Interface, ANM-111, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone (425) 227-2011; facsimile (425) 227-1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.

Background

    On August 25, 2008, Airbus applied for a type certificate for their 
new A350-900 series airplane. Later, Airbus requested and the FAA 
approved an extension to the application for FAA type certification to 
June 28, 2009. The A350-900 series airplane has a conventional layout 
with twin wing-mounted Rolls-Royce Trent engines. It features a twin 
aisle 9-abreast economy class layout, and accommodates side-by-side 
placement of LD-3 containers in the cargo compartment. The basic A350-
900 series airplane configuration accommodates 315 passengers in a 
standard two-class arrangement. The design cruise speed is Mach 0.85 
with a Maximum Take-Off Weight of 602,000 lbs. Airbus proposes the 
A350-900 series airplane to be certified for extended operations 
(ETOPS) beyond 180 minutes at entry into service.

Type Certification Basis

    Under title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus 
must show that the A350-900 series airplane meets the applicable 
provisions of 14 CFR part 25, as amended by Amendments 25-1 through 25-
128.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25) do not contain adequate or appropriate 
safety standards for the A350-900 series airplanes because of a novel 
or unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, A350-900 series airplanes must comply with the fuel vent 
and exhaust emission requirements of 14 CFR part 34 and the noise 
certification requirements of 14 CFR part 36 and the FAA must issue a 
finding of regulatory adequacy under section 611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of

[[Page 75067]]

the type-certification basis under Sec.  21.17(a)(2).
    The current airworthiness standards do not contain adequate safety 
standards for the unique features of the high incidence protection 
system and the alpha-floor system proposed for the Airbus A350-900 
series airplanes. Part I of the following proposed special conditions 
are in lieu of Sec. Sec.  25.103, 25.145(a), 25.145(b)(6), 25.201, 
25.203, 25.207, and 25.1323(d). Part II is in lieu of Sec. Sec.  
25.21(g), 25.105, 25.107, 25.121, 25.123, 25.125, and 25.143.

Novel or Unusual Design Features

    The Airbus A350-900 series airplanes will incorporate the following 
novel or unusual design features: Low speed high incidence protection 
and alpha-floor systems.
    The A350-900 series airplanes will have a novel or unusual feature 
to accommodate the unique features of the high incidence protection and 
the alpha-floor systems. The high incidence protection system replaces 
the stall warning system during normal operating conditions by 
prohibiting the airplane from stalling. The high incidence protection 
system limits the angle of attack at which the airplane can be flown 
during normal low speed operation, impacts the longitudinal airplane 
handling characteristics, and cannot be over-ridden by the crew. The 
existing regulations do not provide adequate criteria to address this 
system.
    The function of the alpha-floor system is to increase automatically 
the thrust on the operating engines under unusual circumstances where 
the airplane pitches to a predetermined high angle of attack or bank 
angle. The regulations do not provide adequate criteria to address this 
system.

Discussion

    The current airworthiness standards do not contain adequate safety 
standards for the unique features of the high incidence protection 
system and the alpha-floor system proposed for Airbus A350-900 series 
airplanes. Special conditions are needed to account for these features. 
The high incidence protection system prevents the airplane from 
stalling and therefore, the stall warning system is not needed during 
normal flight conditions. However, during failure conditions (which are 
not shown to be extremely improbable), the requirements of Title 14 
Code of Federal Regulations (14 CFR) Sec. Sec.  25.203 and 25.207 
apply, although slightly modified (i.e. the flight characteristics at 
the angle of attack for CLMAX must be suitable in the 
traditional sense, and stall warning must be provided in a conventional 
manner).
    The alpha-floor function automatically advances the throttles on 
the operating engines under flight circumstances of low speed if the 
airplane reaches a predetermined high angle of attack. This function is 
intended to provide increased climb capability.
    These proposed special conditions are harmonized with the EASA 
Certification Review Items.

Applicability

    As discussed above, these special conditions are applicable to 
Airbus A350-900 series airplanes. Should Airbus apply at a later date 
for a change to the type certificate to include another model 
incorporating the same novel or unusual design feature, the special 
conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on the Airbus A350-900 series airplane. It is not a rule of general 
applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for Airbus A350-900 series airplanes.
    The current airworthiness standards do not contain adequate safety 
standards for the unique features of the high incidence protection 
system and the alpha-floor system proposed for the Airbus A350. Part I 
of the following proposed special conditions are in lieu of Sec. Sec.  
25.103, 25.145(a), 25.145(b)(6), 25.201, 25.203, 25.207, and 
25.1323(d). Part II are in lieu of Sec. Sec.  25.21(g), 25.105, 25.107, 
25.121, 25.123, 25.125, and 25.143.
    Special Conditions Part I--Stall Protection and Scheduled Operating 
Speeds--Note: In the following paragraphs, ``In icing conditions'' 
means with the ice accretions (relative to the relevant flight phase) 
as defined in 14 CFR part 25, amendment 121 appendix C.

Special Conditions Part I--Stall Protection and Scheduled Operating 
Speeds

Foreword

    In the following paragraphs, ``In icing conditions'' means with the 
ice accretions (relative to the relevant flight phase) as defined in 14 
CFR part 25, amendment 121 appendix C.

1. Definitions

    These Special Conditions addresses novel features of the A350-900 
series airplane and uses terminology that does not appear in 14 CFR 
part 25.
    These terms for the novel features addressed by these special 
conditions are the following:

--High incidence protection system: A system that operates directly and 
automatically on the airplane's flying controls to limit the maximum 
angle of attack that can be attained to a value below that at which an 
aerodynamic stall would occur.
--Alpha-floor system: A system that automatically increases thrust on 
the operating engines when angle of attack increases through a 
particular value.
--Alpha-limit: The maximum angle of attack at which the airplane 
stabilizes with the high incidence protection system operating and the 
longitudinal control held on its aft stop.
--Vmin: The minimum steady flight speed in the airplane 
configuration under consideration with the high incidence protection 
system operating. See paragraph 3 of these Special Conditions.
--Vmin1g: Vmin corrected to 1g conditions. See 
paragraph 3 of these Special Conditions. It is the minimum calibrated 
airspeed at which the airplane can develop a lift force normal to the 
flight path and equal to its weight when at an angle of attack not 
greater than that determined for Vmin.

2. Capability and Reliability of the High Incidence Protection System

    Those paragraphs of 14 CFR part 25 quoted in reference may be 
amended in accordance with these Special Conditions provided that 
acceptable capability and reliability of the high incidence protection 
system can be established by flight test, simulation, and analysis as 
appropriate. The capability and reliability required are as follows:
    1--It shall not be possible during pilot induced maneuvers to 
encounter a stall and handling characteristics shall be acceptable, as 
required by section 5 of these Special Conditions.

[[Page 75068]]

    2--The airplane shall be protected against stalling due to the 
effects of wind-shears and gusts at low speeds as required by section 6 
of these Special Conditions.
    3--The ability of the high incidence protection system to 
accommodate any reduction in stalling incidence must be verified in 
icing conditions.
    4--The high incidence protection system must be provided in each 
abnormal configuration of the high lift devices that is likely to be 
used in flight following system failures.
    5--The reliability of the system and the effects of failures must 
be acceptable in accordance with Sec.  25.1309.

3. Minimum Steady Flight Speed and Reference Stall Speed

    In lieu of Sec.  25.103, Minimum steady flight speed and Reference 
stall speed, we propose the following requirements:
    (a) The minimum steady flight speed, Vmin, is the final 
stabilized calibrated airspeed obtained when the airplane is 
decelerated until the longitudinal control is on its stop in such a way 
that the entry rate does not exceed 1 knot per second.
    (b) The minimum steady flight speed, Vmin, must be 
determined in icing and non-icing conditions with:
    (1) The high incidence protection system operating normally.
    (2) Idle thrust and alpha-floor system inhibited;
    (3) All combinations of flaps setting and, landing gear position 
for which Vmin is required to be determined;
    (4) The weight used when VSR is being used as a factor 
to determine compliance with a required performance standard;
    (5) The most unfavorable center of gravity allowable; and
    (6) The airplane trimmed for straight flight at a speed achievable 
by the automatic trim system.
    (c) The one-g minimum steady flight speed, Vmin1g, is 
the minimum calibrated airspeed at which the airplane can develop a 
lift force (normal to the flight path) equal to its weight, while at an 
angle of attack not greater than that at which the minimum steady 
flight speed of sub-paragraph (a) was determined. It must be determined 
in icing and non icing conditions.
    (d) The reference stall speed, VSR, is a calibrated 
airspeed defined by the applicant. VSR may not be less than 
a 1-g stall speed. VSR must be determined in non icing 
conditions and expressed as:
[GRAPHIC] [TIFF OMITTED] TP19DE12.016

    (1) Engines idling, or, if that resultant thrust causes an 
appreciable decrease in stall speed, not more than zero thrust at the 
stall speed;
    (2) The airplane in other respects (such as flaps and landing gear) 
in the condition existing in the test or performance standard in which 
VSR is being used;
    (3) The weight used when VSR is being used as a factor 
to determine compliance with a required performance standard;
    (4) The center of gravity position that results in the highest 
value of reference stall speed;
    (5) The airplane trimmed for straight flight at a speed achievable 
by the automatic trim system, but not less than 1.13 VSR and 
not greater than 1.3 VSR;
    (6) Alpha-floor system inhibited; and
    (7) The High Incidence Protection System adjusted, at the option of 
the applicant, to allow higher incidence than is possible with the 
normal production system.
    (8) Starting from the stabilized trim condition, apply the 
longitudinal control to decelerate the airplane so that the speed 
reduction does not exceed one knot per second.

4. Stall Warning

    In lieu of Sec.  25.207 we propose the following requirements:

4.1 Normal Operation

    If the capabilities of the high incidence protection system are 
met, then the conditions of paragraph 2 are

[[Page 75069]]

satisfied. These conditions are equivalent safety to the intent of 
Sec.  25.207, Stall Warning, so the provision of an additional, unique 
warning device is not required.

4.2 High Incidence Protection System Failure

    Following failures of the high incidence protection system, not 
shown to be extremely improbable, such that the capability of the 
system no longer satisfies items 1, 2 and 3 of paragraph 2, stall 
warning must be provided and must protect against encountering 
unacceptable characteristics and against encountering stall.
    (a) Stall warning with the flaps and landing gear in any normal 
position must be clear and distinctive to the pilot and meet the 
requirements specified in paragraphs (d) and (e) below.
    (b) Stall warning must also be provided in each abnormal 
configuration of the high lift devices that is likely to be used in 
flight following system failures.
    (c) The warning may be furnished either through the inherent 
aerodynamic qualities of the airplane or by a device that will give 
clearly distinguishable indications under expected conditions of 
flight. However a visual stall warning device that requires the 
attention of the crew within the cockpit is not acceptable by itself. 
If a warning device is used, it must provide a warning in each of the 
airplane configurations prescribed in paragraph (a) above and for the 
conditions prescribed below in paragraphs (d) and (e) below.
    (d) In non icing conditions stall warning must meet the following 
requirements: Stall warning must provide sufficient margin to prevent 
encountering unacceptable characteristics and encountering stall in the 
following conditions:
    (1) In power off straight deceleration not exceeding one knot per 
second to a speed 5 knots or 5 per cent CAS, whichever is greater, 
below the warning onset.
    (2) In turning flight stall deceleration at entry rates up to 3 
knots per second when recovery is initiated not less than one second 
after the warning onset.
    (e) In icing conditions stall warning must provide sufficient 
margin to prevent encountering unacceptable characteristics and 
encountering stall, in power off straight and turning flight 
decelerations not exceeding one knot per second, when the pilot starts 
a recovery maneuver not less than three seconds after the onset of 
stall warning.
    (f) An airplane is considered stalled when the behavior of the 
airplane gives the pilot a clear and distinctive indication of an 
acceptable nature that the airplane is stalled. Acceptable indications 
of a stall, occurring either individually or in combination are:
    (1) A nose-down pitch that cannot be readily arrested
    (2) Buffeting, of a magnitude and severity that is strong and 
effective deterrent to further speed reduction; or
    (3) The pitch control reaches the aft stop and no further increase 
in pitch attitude occurs when the control is held full aft for a short 
time before recovery is initiated
    (g) An aircraft exhibits unacceptable characteristics during 
straight or turning flight decelerations if it is not always possible 
to produce and to correct roll and yaw by unreversed use of aileron and 
rudder controls, or abnormal nose-up pitching occurs.

5. Handling Characteristics at High Incidence

    In lieu of both Sec.  25.201 and Sec.  25.203 we propose the 
following requirements:

5.1 High Incidence Handling Demonstrations

    In lieu of Sec.  25.201: High incidence handling demonstration in 
icing and non icing conditions.
    (a) Maneuvers to the limit of the longitudinal control, in the nose 
up sense, must be demonstrated in straight flight and in 30[deg] banked 
turns with:
    (1) The high incidence protection system operating normally.
    (2) Initial power conditions of:
    I: Power off.
    II: The power necessary to maintain level flight at 1.5 
VSR1, where VSR1 is the reference stall speed 
with flaps in approach position, the landing gear retracted and maximum 
landing weight.
    (3) Alpha-floor system operating normally unless more severe 
conditions are achieved with inhibited alpha floor.
    (4) Flaps, landing gear and deceleration devices in any likely 
combination of positions.
    (5) Representative weights within the range for which certification 
is requested; and
    (6) The airplane trimmed for straight flight at a speed achievable 
by the automatic trim system.
    (b) The following procedures must be used to show compliance in 
non-icing and icing conditions:
    (1) Starting at a speed sufficiently above the minimum steady 
flight speed to ensure that a steady rate of speed reduction can be 
established, apply the longitudinal control so that the speed reduction 
does not exceed one knot per second until the control reaches the stop;
    (2) The longitudinal control must be maintained at the stop until 
the airplane has reached a stabilized flight condition and must then be 
recovered by normal recovery techniques;
    (3) Maneuvers with increased deceleration rates;
    (i) In non icing conditions, the requirements must also be met with 
increased rates of entry to the incidence limit, up to the maximum rate 
achievable.
    (ii) In icing conditions, with the anti-ice system working 
normally, the requirements must also be met with increased rates of 
entry to the incidence limit, up to 3kt/s.
    (4) Maneuver with ice accretion prior to operation of the normal 
anti-ice system
    With the ice accretion prior to operation of the normal anti-ice 
system, the requirement must also be met in deceleration at 1kt/s up to 
FBS (with and without alpha floor).

5.2 Characteristics in High Incidence Maneuvers

    In lieu of Sec.  25.203: Characteristics in High Incidence.
    In icing and non icing conditions:
    (a) Throughout maneuvers with a rate of deceleration of not more 
than 1 knot per second, both in straight flight and in 30[deg] banked 
turns, the airplane's characteristics shall be as follows:
    (1) There shall not be any abnormal nose-up pitching.
    (2) There shall not be any uncommanded nose-down pitching, which 
would be indicative of stall. However reasonable attitude changes 
associated with stabilizing the incidence at Alpha limit as the 
longitudinal control reaches the stop would be acceptable.
    (3) There shall not be any uncommanded lateral or directional 
motion and the pilot must retain good lateral and directional control, 
by conventional use of the controls, throughout the maneuver.
    (4) The airplane must not exhibit buffeting of a magnitude and 
severity that would act as a deterrent from completing the maneuver 
specified in 5.1.(a).
    (b) In maneuvers with increased rates of deceleration some 
degradation of characteristics is acceptable, associated with a 
transient excursion beyond the stabilized Alpha-limit. However the 
airplane must not exhibit dangerous characteristics or characteristics 
that would deter the pilot from holding the longitudinal control on the 
stop for a period of time appropriate to the maneuver.
    (c) It must always be possible to reduce incidence by conventional 
use of the controls.

[[Page 75070]]

    (d) The rate at which the airplane can be maneuvered from trim 
speeds associated with scheduled operating speeds such as V2 
and VREF up to Alpha-limit shall not be unduly damped or be 
significantly slower than can be achieved on conventionally controlled 
transport airplanes.

5.3 Characteristics up to Maximum Lift Angle of Attack

    (a) In non-icing conditions:
    Maneuvers with a rate of deceleration of not more than 1 knot per 
second up to the angle of attack at which
[GRAPHIC] [TIFF OMITTED] TP19DE12.019

was obtained as defined in paragraph 3 must be demonstrated in straight 
flight and in 30[deg] banked turns with:
    (1) The high incidence protection deactivated or adjusted, at the 
option of the applicant, to allow higher incidence than is possible 
with the normal production system.
    (2) Automatic thrust increase system inhibited
    (3) Engines idling
    (4) Flaps and landing gear in any likely combination of positions
    (5) The airplane trimmed for straight flight at a speed achievable 
by the automatic trim system.
    (b) In icing conditions:
    Maneuvers with a rate of deceleration of not more than 1 knot per 
second up to the maximum angle of attack reached during maneuvers from 
5.1(b)(3)(ii) must be demonstrated in straight flight with:
    (1) The high incidence protection deactivated or adjusted, at the 
option of the applicant, to allow higher incidence than is possible 
with the normal production system.
    (2) Automatic thrust increase system inhibited.
    (3) Engines idling.
    (4) Flaps and landing gear in any likely combination of positions.
    (5) The airplane trimmed for straight flight at a speed achievable 
by the automatic trim system.
    (c) During the maneuvers used to show compliance with paragraphs 
(a) (b) above, the airplane must not exhibit dangerous characteristics 
and it must always be possible to reduce angle of attack by 
conventional use of the controls. The pilot must retain good lateral 
and directional control, by conventional use of the controls, 
throughout the maneuver.

6. Atmospheric Disturbances

    Operation of the high incidence protection system must not 
adversely affect aircraft control during expected levels of atmospheric 
disturbances, nor impede the application of recovery procedures in case 
of wind-shear. This shall be demonstrated in non icing and icing 
conditions.

7. Alpha Floor

    In icing and non icing conditions, the Alpha-floor setting must be 
such that the airplane can be flown at the speeds and bank angles 
specified in Sec.  25.143(h). It also must be shown that the alpha 
floor setting does not interfere with normal maneuvering of the 
airplane. In addition there must be no alpha-floor triggering unless 
appropriate when the aircraft is flown in usual operational maneuvers 
and in turbulence.

8. Proof of Compliance

    We propose that the following requirement be made in addition to 
those in Sec.  25.21(b):
    (b) The flying qualities will be evaluated at the most unfavorable 
CG position.

9. For These Regulations, Sec. Sec.  25.145(a), 25.145(b)(6) and 
25.1323(d), We Propose the Following Requirements

Sec.  25.145(a) Vmin in lieu of ``stall identification''
Sec.  25.145(b)(6) Vmin in lieu of VSW
Sec.  25.1323(d) ``From 1.23 VSR to Vmin'' in 
lieu of ``1.23 VSR to stall warning speed'' and ``speeds 
below Vmin'' in lieu of ``speeds below stall warning''

Special Conditions Part II--Credit for Robust Envelope Protection in 
Icing Conditions

    1. Define the stall speed as provided in SC Part I in lieu of Sec.  
25.103.
    2. We propose the following requirements in lieu of Sec.  
25.105(a)(2)(i):
    In lieu of Sec.  25.105(a)(2)(i) Take-off.
    (i) The V2 speed scheduled in non icing conditions does 
not provide the maneuvering capability specified in Sec.  25.143(h) for 
the takeoff configuration, or
    3. In lieu of Sec.  25.107(c) (g) we propose the following 
requirements, with additional sections (c') and (g'):
    In lieu of Sec.  25.107(c) and (g) Take-off speeds.
    (c) In non icing conditions V2, in terms of calibrated 
airspeed, must be selected by the applicant to provide at least the 
gradient of climb required by Sec.  25.121(b) but may not be less 
than--
    (1) V2MIN;
    (2) VR plus the speed increment attained (in accordance 
with Sec.  25.111(c)(2)) before reaching a height of 35 feet above the 
takeoff surface; and
    (3) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (c) In icing conditions with the ``take-off ice'' accretion defined 
in Appendix C, V2 may not be less than--
    (1) The V2 speed determined in non icing conditions
    (2) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (g) In non icing conditions, VFTO, in terms of 
calibrated airspeed, must be selected by the applicant to provide at 
least the gradient of climb required by Sec.  25.121(c), but may not be 
less than--
    (1) 1.18 VSR; and
    (2) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (g) In icing conditions with the ``Final take-off ice'' accretion 
defined in Appendix C, VFTO, may not be less than--
    (1) The VFTO speed determined in non icing conditions.
    (2) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    4. In lieu of Sec.  25.121(b)(2)(ii)(A), Sec.  25.121(c)(2)(ii)(A), 
Sec.  25.121(d)(2)(ii), we propose the following requirements:
    In lieu of Sec.  25.121(b)(2)(ii)(A) Climb: One-engine inoperative:
    (A) The V2 speed scheduled in non icing conditions does 
not provide the maneuvering capability specified in Sec.  25.143(h) for 
the take-off configuration; or
    In lieu of Sec.  25.121(c)(2)(ii)(A) Climb: One-engine inoperative:
    (A) The VFTO speed scheduled in non icing conditions 
does not provide the maneuvering capability specified in Sec.  
25.143(h) for the en-route configuration; or
    In lieu of Sec.  25.121(d)(2)(ii) Climb: One-engine inoperative:
    (d)(2) The requirements of sub-paragraph (d)(1) of this paragraph 
must be met:
    (ii) In icing conditions with the approach Ice accretion defined in 
Appendix C, in a configuration corresponding to the normal all-engines-
operating procedure in which Vmin1g for this configuration 
does not exceed 110% of the Vmin1g for the related all-
engines-operating landing configuration in icing, with a climb speed 
established with normal landing procedures, but not more than 1.4 
VSR (VSR determined in non icing conditions).
    5. In lieu of Sec.  25.123(b)(2)(i) we propose the following 
requirements:
    In lieu of Sec.  25.123(b)(2)(i) En-route flight paths:
    (i) The minimum en-route speed scheduled in non icing conditions 
does not provide the maneuvering capability specified in Sec.  
25.143(h) for the en-route configuration, or

[[Page 75071]]

    6. In lieu of Sec.  25.125(b)(2)(ii)(B), we propose paragraph Sec.  
25.125(b)(2)(ii)(C) be removed and replaced by the following 
requirements:
    In lieu of Sec.  25.125(b)(2)(ii)(B) and Sec.  25.125(b)(2)(ii)(C) 
Landing.
    (B) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h) with the landing ice accretion defined in appendix C.
    7. In lieu of, Sec.  25.143(j)(2)(i) we propose the following 
requirements for controllability and maneuverability:
    In lieu of Sec.  25.143(j)(2)(i) General.
    (i) The airplane is controllable in a pull-up maneuver up to 1.5 g 
load factor or lower if limited by AOA protection; and
    8. In lieu of Sec.  25.207, Stall warning, to read as the 
requirements defined in SC Part I., Section 4.

Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-30441 Filed 12-18-12; 8:45 am]
BILLING CODE 4910-13-P