Special Conditions: Airbus Model A350-900 Series Airplane; Flight-Envelope Protection (Icing and Non-Icing Conditions); High-Incidence Protection and Alpha-Floor Systems, 65562-65571 [2014-26289]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 79, Number 214 (Wednesday, November 5, 2014)]
[Rules and Regulations]
[Pages 65562-65571]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-26289]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2012-1207; Special Conditions No. 25-517-SC]


Special Conditions: Airbus Model 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: Final special conditions.

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

[[Page 65563]]

SUMMARY: These special conditions are issued for Airbus Model 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 these design features. These 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: Effective November 5, 2014.

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:

Background

    On August 25, 2008, Airbus applied for a type certificate for their 
new Model A350-900 series airplane. Later, Airbus requested, and the 
FAA approved, an extension to the application for FAA type 
certification to November 15, 2009. The Model A350-900 series airplane 
has a conventional layout with twin, wing-mounted, Rolls-Royce Trent 
XWB 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 Model 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.

Type Certification Basis

    Under title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus 
must show that the Model A350-900 series airplane meets the applicable 
provisions of 14 CFR part 25, as amended by Amendments 25-1 through 25-
129.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25) do not contain adequate or appropriate 
safety standards for the Model A350-900 series airplane 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, Model 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. The FAA must issue 
a finding of regulatory adequacy under Sec.  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 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 for the Airbus Model A350-900 series 
airplane. Part I of the following special conditions is 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 Model A350-900 series airplane will incorporate the 
following novel or unusual design features: High-incidence protection 
and 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 overridden 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 high-incidence protection system and the alpha-floor 
system for Airbus Model A350-900 series airplanes. Special conditions 
are needed.
    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) sections 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 special conditions are intended to parallel the requirements 
provided in EASA A350 Certification Review Item (CRI):
     B-1, ``Stalling and Scheduled Operating Speeds,'' and
     B-09, ``Flight in Icing Conditions,'' to adapt the new 
standards for performance and handling characteristics of transport-
category airplanes in icing conditions introduced by Amendment 25-121 
to the envelope-protected Airbus Model A350-900 series airplane.
    These 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.

Discussion of Comments

    Notice of proposed special conditions No. 25-12-09-SC for the 
Airbus Model A350-900 series airplanes was published in the Federal 
Register on December 19, 2012 (77 FR 75066). Comments were received 
from Transport Canada Civil Aviation (TCCA) and Ag[ecirc]ncia Nacional 
De Avia[ccedil][atilde]o Civil (ANAC).

TCCA Comments and FAA Responses

    1. TCCA commented that, despite informal attempts to obtain 
harmonization on requirements for high-incidence protection systems,

[[Page 65564]]

harmonization has not been achieved. However, TCCA also correctly 
points out that this will be the subject of an ARAC harmonization 
effort through the Flight Test Harmonization Working Group (FTHWG).
    The FAA agrees with TCCA that the ARAC FTHWG will attempt to reach 
a harmonized position with regard to TCCA and ANAC comments; these 
special conditions are necessary in the interim.
    2. TCCA also commented that the concept of using VSR to 
establish operational speeds in both icing and non-icing conditions was 
well established, and not significantly commented upon, in earlier 
rulemaking efforts. Because these special conditions modify that 
concept in icing conditions, TCCA requested that this point be 
carefully evaluated.
    The FAA agrees with TCCA that this point should be carefully 
evaluated in the ARAC FTHWG. However, at this time, the FAA considers 
that the robust flight-envelope protection requirements of these 
special conditions provide compensating requirements that result in an 
adequate level of safety.
    3. In consideration of a recent accident on a test airplane, TCCA 
requested that consideration be given to including specific 
requirements for having the protection system functioning in ground-
effect during takeoff and landing.
    The FAA agrees that this point deserves consideration, and notes 
that it should be carefully evaluated in the ARAC FTHWG. However, at 
this time, the FAA considers that the general requirements (those that 
apply in all phases of flight) of these special conditions provide an 
adequate level of safety.
    4. The TCCA notes that many airframe ice-protection systems have a 
probable failure condition (single failure) where some or all of the 
airframe ice protection is lost. TCCA further notes that no proposed 
demonstration requirements are specified for failures of airframe ice 
protection, which are most likely in the probable/remote range.
    The FAA acknowledges this point, and notes that it will be further 
evaluated in the ARAC FTHWG. However, at this time, it is the FAA's 
opinion that these special conditions, along with the requirements of 
Sec.  25.1309, provide an adequate level of safety.
    5. Demonstration requirements for failures of the airframe ice-
protection system less than extremely improbable should be specified, 
according to the TCCA.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG. However, at this time, the FAA believes that the general 
requirements of these special conditions, along with the general 
requirements of Sec.  25.1309, provide an adequate level of safety.
    6. TCCA also opined that the protection system should be effective 
in foreseeable maneuvers such as the sideslip that is developed during 
takeoff and landing in crosswind conditions.
    The FAA agrees that this point should receive additional evaluation 
in the ARAC FTHWG. However, after consideration, it is the FAA's 
position that the general requirements of these special conditions, 
combined with the current demonstration requirements in crosswind 
conditions, provide an adequate level of safety.
    7. TCCA recommended introducing a new requirement: ``The protection 
system must be designed to operate and perform its intended function in 
sideslip angles appropriate to normal airplane operation.''
    The FAA intends that this point will be part of the analysis 
conducted by the ARAC FTHWG. However, at this time, it is the FAA's 
position that the general requirements of these special conditions, 
combined with the general flight-test requirements in various sideslip 
conditions, provide an adequate level of safety.
    8. TCCA also recommended guidance on the adverse effects of 
airframe and system tolerances that should be taken into account when 
determining VMin1g.
    The FAA considers that the general requirements of these special 
conditions, along with the guidance in AC 25-7, provide an adequate 
level of safety. However, additional evaluation may be conducted in the 
ARAC FTHWG.
    9. TCCA requested clarification on whether the stall warning 
required for each abnormal configuration likely to be used, following 
system failure, should include both icing and non-icing requirements.
    Whether the stall warning must include both icing and non-icing 
requirements depends upon the failure scenario, and whether it meets 
Sec.  25.1309. Reliance on Sec.  25.1309 requirements provides an 
adequate level of safety in this case. However, this subject may be 
revisited in the upcoming ARAC FTHWG.
    10. TCCA recommended that the FAA issue guidance on accounting for 
the adverse effects of airframe and system tolerances as a result of 
leading-edge degradation due to damage within permissible limits, and 
contamination due to dirt and insects (when demonstrating handling 
characteristics to alpha max).
    The FAA may issue such guidance, subsequent to evaluation in the 
ARAC FTHWG. However, at this time, it is the FAA's opinion that the 
general requirements of these special conditions, along with the 
guidance in AC 25-7, provide an adequate level of safety.
    11. TCCA also recommended additional flight testing requirements to 
ensure the ``robustness'' of the high-angle-of-attack protection 
systems, in both icing and non-icing conditions.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG. However, at this time, the FAA considers that additional 
flight testing requirements are not necessary, as the requirements of 
these special conditions provide an adequate level of safety.
    12. TCCA requested that the FAA add further clarification for 
sections 5.1(b)(3)i and 5.1(b)(3)ii of these special conditions 
regarding the requirement for straight or turning flight, and power 
setting.
    The FAA agrees that this point should be carefully revisited in the 
ARAC FTHWG. However, at this time, the FAA considers that the 
requirements of these sections are sufficiently defined in section 
5.1(a).
    13. TCCA recommended that the FAA delete section 5.3(b), if it 
adopted TCCA's earlier comments.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG.
    14. TCCA recommended that operational speeds should be determined 
based on a factored VSR or Vmin1g in icing 
conditions, in addition to the requirement for minimum maneuver 
margins. TCCA has provided specific proposals for those factors.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG. However, at this time, the FAA considers that the 
requirements of these special conditions provide an adequate level of 
safety because minimum maneuver margins are typically more limiting 
than those based on factored VSR or Vmin1g.

ANAC Comments

    1. ANAC questioned the use of different operational-speed bases for 
icing and non-icing conditions.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG. However, at this time, it is the FAA's opinion that the 
differing requirements for icing and non-icing conditions are 
appropriate and provide an adequate level of safety. The non-icing 
speed basis is used for nearly

[[Page 65565]]

every flight, while the icing speed basis is based on an assumed 
lengthy accumulation of ice, which may not be present on every flight 
in icing conditions. Therefore, the safety trade-off (i.e., differing 
requirements) between increased approach speeds and margin to stall is 
more appropriate in icing conditions.
    2. ANAC proposed to have the same basic requirements in icing and 
non-icing, allowing only some degradation in handling characteristics 
at VCLmax in icing conditions.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG. However, at this time, the FAA considers that the rationale 
for differing requirements in icing and non-icing conditions is 
appropriate and provides an adequate level of safety.
    3. ANAC recommended that the same high-incidence-protection 
demonstration of ``maximum rate achievable'' should be required for 
icing conditions.
    The FAA agrees that this point should be carefully evaluated in the 
ARAC FTHWG. However, at this time, the FAA considers that the 
requirements of these special conditions provide an adequate level of 
safety. Historically, the FAA has allowed a small degradation for stall 
demonstrations in icing conditions (i.e., exceptions for high-entry-
rate stalls). We have extended this philosophy to the requirements of 
these special conditions.

Additional FAA Response to Comments

    The FAA acknowledges these comments, which will be fully discussed 
and resolved in the upcoming ARAC FTHWG sessions. The FAA notes that 
these special conditions are intended to parallel the requirements 
provided in EASA (as the certificating authority) A350 Certification 
Review Item (CRI):
     B-1, ``Stalling and Scheduled Operating Speeds,'' and
     B-09, ``Flight in Icing Conditions,'' to adapt the new 
standards for performance and handling characteristics of transport-
category airplanes in icing conditions introduced by Amendment 25-121 
to the envelope-protected Airbus Model A350-900 series airplane.
    In the meantime, the FAA, as the validating authority, finds that 
these special conditions provide an adequate level of safety. No 
changes to the special conditions were made based on TCCA and ANAC 
comments.

Applicability

    As discussed above, these special conditions are applicable to 
Airbus Model 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.
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register; however, as the certification date for the Airbus 
Model A350-900 series airplane is imminent, the FAA finds that good 
cause exists to make these special conditions effective upon 
publication.

Conclusion

    This action affects only certain novel or unusual design features 
on the Airbus Model 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 Special Conditions

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Airbus Model 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 for the Airbus A350. Part I of the 
following special conditions is 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.

    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 address novel or unusual design features 
of the Airbus Model A350-900 series airplane and use terminology that 
does not appear in 14 CFR part 25. For the purpose of these special 
conditions, the following terms describe certain aspects of these novel 
or unusual design features:
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.
VCLmax
    An airspeed calculated from a variety of factors including load 
factor normal to the flight path at VCLmax, airplane gross 
weight, aerodynamic reference wing area, and dynamic pressure.
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

    These special conditions are issued in lieu of the paragraphs of 14 
CFR part 25 referenced below. 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 must not be possible during pilot induced maneuvers to 
encounter a stall and handling characteristics must be acceptable, as 
required by section 5 of these Special Conditions.
    2--The airplane must be protected against stalling due to the 
effects of

[[Page 65566]]

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, the following requirements apply:
    (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. (See Appendix A, 
paragraph 3)
    (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 1g 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 1g stall speed. VSR must be determined in non-icing 
conditions and expressed as:
[GRAPHIC] [TIFF OMITTED] TR05NO14.011

    (e) VCLmax is determined in non-icing conditions with:
    (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 1 knot per second.

4. Stall Warning

    In lieu of Sec.  25.207, the following requirements apply:

4.1 Normal Operation

    If the capabilities of the high-incidence protection system are 
met, then the conditions of paragraph 2 are satisfied. These conditions 
provide an equivalent level of safety to Sec.  25.207, Stall Warning, 
so the provision of an additional, unique warning device is not 
required.

[[Page 65567]]

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 1 knot per 
second to a speed 5 knots or 5 percent 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 1 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 1 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, the following 
requirements apply:

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 pitch, 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. (See Appendix A, paragraph 5)

    (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 (see Appendix A, paragraph 6).
    (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 1 knot per second until the control reaches the stop 
(see Appendix A, paragraph 3).
    (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 (see 
Appendix A, paragraph 7).
    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 must be as follows:
    (1) There must not be any abnormal nose-up pitching.
    (2) There must 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. (See 
Appendix A, paragraph 7.3)
    (3) There must 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.

[[Page 65568]]

    (c) It must always be possible to reduce incidence by conventional 
use of the controls.
    (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 must 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 VCLmax 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) and (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 must 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

    In addition to those in Sec.  25.21(b), the following requirement 
applies:
    (b) The flying qualities must be evaluated at the most unfavorable 
center of gravity (CG) position.

9. For Sec. Sec.  25.145(a), 25.145(b)(6), and 25.1323(d), the 
Following Requirements Apply

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. In lieu of Sec.  25.21(g)(1), the following requirement applies:
    In lieu of Sec.  25.21, Proof of compliance:
    (g) The requirements of this subpart associated with icing 
conditions apply only if certification for flight in icing conditions 
is desired. If certification for flight in icing conditions is desired, 
the following requirements also apply (see AC 25-25):
    (1) Each requirement of this subpart, except Sec. Sec.  25.121(a), 
25.123(c), 25.143(b)(1) and (b)(2), 25.149, 25.201(c)(2), 25.207(c) and 
(d), and 25.251(b) through (e), must be met in icing conditions. 
Compliance must be shown using the ice accretions defined in Appendix 
C, assuming normal operation of the airplane and its ice protection 
system in accordance with the operating limitations and operating 
procedures established by the applicant and provided in the Airplane 
Flight Manual.
    2. Define the stall speed as provided in SC Part I, in lieu of 
Sec.  25.103.
    3. The following requirements apply in lieu of Sec.  
25.105(a)(2)(i):
    In lieu of Sec.  25.105, Take-off:
    (a) The take-off speeds prescribed by Sec.  25.107, the accelerate-
stop distance prescribed by Sec.  25.109, the take-off path prescribed 
by Sec.  25.111, and the take-off distance and take-off run prescribed 
by Sec.  25.113, must be determined, and the net take-off flight path 
prescribed by Sec.  25.115, must be determined in the selected 
configuration for take-off at each weight, altitude, and ambient 
temperature within the operational limits selected by the applicant--
    . . .
    (2) In icing conditions, if in the configuration of Sec.  25.121(b) 
with the ``Take-off Ice'' accretion defined in Appendix C:
    (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
    4. In lieu of Sec.  25.107(c) and (g), the following requirements 
apply, with additional sections (c') and (g'):
    In lieu of Sec.  25.107, 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).
    5. In lieu of Sec. Sec.  25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A), 
and 25.121(d)(2)(ii), the following requirements apply:

[[Page 65569]]

    In lieu of Sec.  25.121, Climb: One-engine inoperative:
    (b) Take-off; landing gear retracted. In the take-off configuration 
existing at the point of the flight path at which the landing gear is 
fully retracted, and in the configuration used in Sec.  25.111 but 
without ground effect,
    (2) The requirements of subparagraph (b)(1) of this paragraph must 
be met:
    . . .
    (ii) In icing conditions with the ``Take-off Ice'' accretion 
defined in Appendix C, if in the configuration of Sec.  25.121(b) with 
the ``Take-off Ice'' accretion:
    (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
    (c) Final take-off. In the en-route configuration at the end of the 
take-off path determined in accordance with Sec.  25.111:
    (2) The requirements of subparagraph (c)(1) of this paragraph must 
be met:
    . . .
    (ii) In icing conditions with the ``Final Take-off Ice'' accretion 
defined in Appendix C, if:
    (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
    (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).
    6. In lieu of Sec.  25.123(b)(2)(i), the following requirements 
apply:
    In lieu of Sec.  25.123, En-route flight paths:
    (b) The one-engine-inoperative net flight path data must represent 
the actual climb performance diminished by a gradient of climb of 1.1% 
for two-engined airplanes, 1.4% for three-engined airplanes, and 1.6% 
for four engined airplanes.
    (2) In icing conditions with the ``En-route ice'' accretion defined 
in Appendix C if
    (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 enroute configuration, or
    7. In lieu of Sec.  25.125(b)(2)(ii)(B), remove Sec.  
25.125(b)(2)(ii)(C) and replaced with the following requirements:
    In lieu of Sec.  25.125, Landing.
    (b) In determining the distance in (a):
    (1) The airplane must be in the landing configuration.
    (2) A stabilized approach, with a calibrated airspeed of not less 
than VREF, must be maintained down to the 50-foot height.
    (i) In non-icing conditions, VREF may not be less than:
    (A) 1.23VSR0;
    (B) VMCL established under Sec.  25.149(f); and
    (C) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h).
    (ii) In icing conditions, VREF may not be less than:
    (A) The speed determined in sub-paragraph (b)(2)(i) of this 
paragraph;
    (B) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h) with the landing ice accretion defined in appendix C.
    8. In lieu of Sec.  25.143(j)(2)(i), the following requirements for 
controllability and maneuverability apply:
    In lieu of Sec.  25.143, General:
    (j) For flight in icing conditions before the ice protection system 
has been activated and is performing its intended function, the 
following requirements apply:
    (1) If activating the ice protection system depends on the pilot 
seeing a specified ice accretion on a reference surface (not just the 
first indication of icing), the requirements of Sec.  25.143 apply with 
the ice accretion defined in appendix C, part II(e).
    (2) For other means of activating the ice protection system, it 
must be demonstrated in flight with the ice accretion defined in 
appendix C, part II(e) that:
    (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
    (ii) There is no pitch control force reversal during a pushover 
maneuver down to 0.5 g load factor
    9. In lieu of Sec.  25.207, Stall warning, change to read as the 
requirements defined in Special Conditions Part I, above.

Appendix A--Guidance Material: Stalling and Scheduled Operating Speeds

1. Introduction

    This Guidance Material provides suggested means of compliance 
for various aspects of Special Conditions Part I and replaces the AC 
25-7C sections that are no longer applicable due to the conditions 
of Special Conditions Part 1.

2. Alpha Protection Tolerances

    Flight testing for handling characteristics should be 
accomplished with the airplane build and system tolerances set to 
the most adverse condition for high-incidence protection. Flight 
testing for minimum steady flight speed and reference stall speed 
may be made with nominal airframe tolerances and AOA protection 
system settings if the combined root-sum-square (square root of the 
sum of the squares of each tolerance) effect of the tolerances is 
less than 1 knot. If the effect is greater than 1 knot, the most adverse airframe build and high-incidence 
protection system tolerance should be used.

3. Minimum Steady Flight Speed Entry Rate

    In lieu of Sec.  25.103(a) and Sec.  25.203(a), see paragraphs 3 
and 5.2 of Special Conditions Part I.
    The minimum steady flight speed entry rate is defined as 
follows:
[GRAPHIC] [TIFF OMITTED] TR05NO14.012

4. Maneuvering Capabilities at Scheduled Operating Speeds

(See Sec.  25.143(h))

    (1) The maneuver capabilities specified in Sec.  25.143 (h) 
should be achieved at constant CAS.
    (2) A low thrust or power setting normally will be the critical 
case for demonstrating the required maneuver capabilities. The 
thrust/power settings specified in paragraph Sec.  25.143(h) are the 
maximum values that may be used in such cases. However, if the angle 
of attack at which the stick stop is reached (or other relevant 
characteristic occurs) is reduced with increasing thrust or power, 
it should be ensured that the required maneuver capabilities are 
retained at all higher thrust or power settings appropriate to the 
flight condition.
    (3) The thrust or power setting for the all-engines operating 
condition at V2+xx should

[[Page 65570]]

include any value used in noise abatement procedure.

5. Power Setting for Power-On Handling to High Incidence

(In lieu of Sec.  25.201(a)(2), see paragraph 5.1 of Special 
Conditions Part I)

    The power for power-on maneuver demonstrations to high incidence 
is that power necessary to maintain level flight without ice at a 
speed of 1.5 VSR1 at maximum landing weight, with flaps 
in the approach position and landing gear retracted, where 
VSR1 is the reference stall speed without ice in the same 
conditions (except power and effect of ice). The flap position to be 
used to determine this power setting is that position in which the 
reference stall speed does not exceed 110% of the reference stall 
speed with the flaps in the most extended landing position.

6. Position of Deceleration Devices During Handling to High Incidence

(In lieu of Sec.  25.201, see paragraph 5.1 of Special Conditions 
Part I)

    Demonstrations of maneuvers to high incidence for compliance 
with Sec.  25.201 should include demonstrations with deceleration 
devices deployed for all flap positions unless limitations against 
use of the devices with particular flap positions are imposed. 
``Deceleration devices'' include spoilers when used as air brakes, 
and thrust reversers when use in flight is permitted. High-incidence 
maneuver demonstrations with deceleration devices deployed should 
normally be carried out with an initial power setting of power off, 
except where deployment of the deceleration devices while power is 
applied is likely to occur in normal operations (e.g. use of 
extended air brakes during landing approach). Demonstrations with 
Alpha-floor both inhibited and operating normally should be 
included.

7. Characteristics During High-Incidence Maneuvers

    In lieu of Sec.  25.203, see paragraph 5.2 of Special Conditions 
Part I.
    (1) The behavior of the airplane includes the behavior as 
affected by the normal functioning of any systems with which the 
airplane is equipped, including devices intended to alter the high-
incidence handling characteristics of the airplane.
    (2) Unless the design of the automatic flight control system of 
the airplane protects against such an event, the high-incidence 
characteristics, when the airplane is maneuvered under the control 
of the automatic flight control system should be investigated.
    (3) Any reduction of pitch attitude associated with stabilizing 
the incidence at Alpha limit should be achieved smoothly, at a low 
pitch rate, such that it is not likely to be mistaken for natural 
stall identification.

8. Atmospheric Disturbances

    See paragraph 6 of Special Conditions Part I.
    In establishing compliance with paragraph 6 of Special 
Conditions Part I, the high-incidence protection system and alpha-
floor system should be assumed to be operating normally. Simulator 
studies and analyses may be used but will need to be validated by 
limited flight testing to confirm handling qualities, at critical 
loadings, up to the maximum incidence shown to be reached by such 
studies and analyses.

9. Alpha Floor

    See paragraph 7 of Special Conditions Part I.
    Compliance with paragraph 7 of Special Conditions Part I should 
be considered as being met if alpha-floor setting provides a 
maneuvering capability of 40[deg] bank angle,
    --in the landing configuration
    --at VREF without ice, and at the recommended final 
approach speed with ice
    --with the thrust for wings level unaccelerated -3[deg] glide 
path,
    without alpha-floor triggering.

Appendix B--Guidance Material

    The following guidance is in lieu of AC 25-25, Performance and 
Handling Characteristics in the Icing Conditions Specified in Part 
25, Appendix C:

Section 3. ACCEPTABLE MEANS OF COMPLIANCE--FLIGHT TEST PROGRAM

    1. In lieu of b. Stall Speed, 25.103, the requirements in 
Special Conditions Part 1, 3. Minimum Steady Flight Speed and 
Reference Stall Speed are made.
    2. In lieu of d., Takeoff Path, Sec.  25.111, the following 
guidance is made.
    If V2 speed scheduled in icing conditions is greater 
than V2 in non-icing conditions take-off demonstrations 
should be repeated to substantiate the speed schedule and distances 
for take-off in icing conditions. The effect of the take-off speed 
increase, thrust loss, and drag increase on the take-off path may be 
determined by a suitable analysis.
    3. In lieu of i., Controllability and Maneuverability--General, 
Sec.  25.143, the following guidance is made:
    a. Sec.  25.143(4)(c)4 Test maneuver for showing compliance with 
Sec.  25.143(i)(3): Conduct steady heading sideslips to full rudder 
input, 180 pounds rudder force, or full lateral control authority 
(whichever comes first) at a trim speed corresponding to the minimum 
AFM speed and the power or thrust for a minus 3 degrees flight path 
angle.
    b. Sec.  25.143(5)(b) If activation of the ice protection system 
depends on a means of recognition other than that defined in 
paragraph (a) above, it is acceptable to demonstrate adequate 
controllability with the ice accretion prior to normal system 
operation, as follows. In the configurations listed below, trim the 
airplane at the specified speed, conduct a pull-up maneuver to 1.5g 
(or lower if limited by AOA protections) and pushover maneuver to 
0.5g, and show that longitudinal control forces do not reverse.
    (1) High lift devices retracted configuration (or holding 
configuration if different), holding speed, power or thrust for 
level flight.
    (2) Landing configuration, VREF for non-icing 
conditions, power or thrust for landing approach. (stop pull up 
after achievement of 1.5g or peak load factor with Full Back Stick).
    4. In lieu of j., Longitudinal Control, Sec.  25.145(2)(c), the 
following guidance is made for (c):

((1), (2), (a) and (b) are retained)

    In the configurations listed below, trim the airplane at the 
minimum AFM speed. Reduce speed using elevator control to the 
minimum steady achievable speed and demonstrate prompt recovery to 
the trim speed using elevator control.
    1 High lift devices retracted configuration, maximum continuous 
power or thrust.
    2 Maximum lift landing configuration, maximum continuous power 
or thrust.
    5. In lieu of q., Stall Demonstration, Sec.  25.201, see the 
requirements in Special Conditions Part I, Stall Protection and 
Scheduled Operating Speeds.
    6. In lieu of r., Stall Warning, Sec.  25.207, see the 
requirements in Special Conditions Part I, paragraph 4--Stall 
Warning.
    7. In lieu of u., Natural Icing Conditions, Sec.  25.1419(b), 
revise the ice accretion Tables 3 & 4 as follows:

                                      Table 3--Holding Scenario--Maneuvers
----------------------------------------------------------------------------------------------------------------
           Configuration                       CG                  Trim speed                  Maneuver
----------------------------------------------------------------------------------------------------------------
Flaps up, gear up..................  Optional (aft range)..  Holding, except at       Level, 40[deg]
                                                              Minimum AFM speed for   banked turn,
                                                              the high AoA maneuver.  Bank-to-bank rapid
                                                                                      roll, 30[deg]-30[deg],
                                                                                      Speed-brake
                                                                                      extension, retraction,
                                                                                      Deceleration to
                                                                                      alpha-max (1 knot/second
                                                                                      deceleration rate, wings
                                                                                      level, power off).
Flaps in intermediate positions,     Optional (aft range)..  Minimum AFM speed.....  Level deceleration in a 1
 gear up.                                                                             knot/second deceleration
                                                                                      until deceleration is
                                                                                      stopped due to alpha-floor
                                                                                      triggering.

[[Page 65571]]

 
Landing flaps, gear down...........  Optional (aft range)..  VREF (Minimum AFM        Level, 40[deg]
                                                              speed).                 banked turn,
                                                                                      Bank-to-bank rapid
                                                                                      roll, 30[deg]-30[deg],
                                                                                      Speed-brake
                                                                                      extension, retraction (if
                                                                                      approved),
                                                                                      Deceleration to
                                                                                      alpha-max (1 knot/second
                                                                                      deceleration rate, wings
                                                                                      level, power off).
----------------------------------------------------------------------------------------------------------------


                                  Table 4--Approach/Landing Scenario--Maneuvers
----------------------------------------------------------------------------------------------------------------
                   Ice accretion
 Test condition    thickness (*)      Configuration           CG            Trim speed            Maneuver
----------------------------------------------------------------------------------------------------------------
                 First 13 mm (0.5   Flaps up, gear up  Optional (aft     Holding.........  No specific test.
                  inch).                                range).
1..............  Additional 6.3 mm  First              Optional (aft     Minimum AFM        Level
                  (0.25 in) (19 mm   intermediate       range).           speed.            40[deg] banked turn,
                  (0.75 in) total).  flaps, gear up.                                        Bank-to-bank
                                                                                            rapid roll, 30[deg]-
                                                                                            30[deg],
                                                                                            Speed brake
                                                                                            extension and
                                                                                            retraction (if
                                                                                            approved),
                                                                                            1kt/s Level
                                                                                            deceleration until
                                                                                            the deceleration is
                                                                                            stopped due to alpha-
                                                                                            floor triggering.
2..............  Additional 6.3 mm  First              Optional (aft     Minimum AFM        Bank-to-bank
                  (0.25 in) (25 mm   intermediate       range).           speed.            rapid roll, 30[deg]-
                  (1.00 in) total).  flaps, gear up                                         30[deg],
                                     (as applicable).                                       Speed brake
                                                                                            extension and
                                                                                            retraction (if
                                                                                            approved),
                                                                                            1kt/s Level
                                                                                            deceleration until
                                                                                            the deceleration is
                                                                                            stopped due to alpha-
                                                                                            floor triggering.
3..............  Additional 6.3 mm  Landing flaps,     Optional (aft     VREF (Minimum      Bank-to-bank
                  (0.25 in) (31 mm   gear down).        range).           AFM speed).       rapid roll, 30[deg]-
                  (1.25 in) total).                                                         30[deg],
                                                                                            Speed brake
                                                                                            extension and
                                                                                            retraction (if
                                                                                            approved),
                                                                                            Bank to
                                                                                            40[deg]
                                                                                            Deceleration
                                                                                            to alpha-max.
----------------------------------------------------------------------------------------------------------------
(*) The indicated thickness is that obtained on the parts of the unprotected airfoil with the highest collection
  efficiency.

    8. In lieu of AC 25-25, 3. v., Failure conditions, Sec.  
25.1309, the following guidance is made for (2)(d):
    (2) Acceptable Test Program
    (d) In the configurations listed below, trim the airplane at the 
minimum AFM speed. Decrease speed to the minimum steady achievable 
speed, plus 1 second and demonstrate prompt recovery using the same 
recovery maneuver as for the non-contaminated airplane. It is 
acceptable for stall warning to be provided by a different means 
(for example, by the behavior of the airplane) for failure cases not 
considered probable.
    1 High lift devices retracted configuration: Straight/Power Off.
    2 Landing configuration: Straight/Power Off.

Issued in Renton, Washington.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-26289 Filed 11-4-14; 8:45 am]
BILLING CODE 4910-13-P