80_FR_55399 80 FR 55221 - Special Conditions: Bombardier Aerospace Inc. Model BD-500-1A10 and BD-500-1A11 Airplanes; Flight-Envelope Protection, High Incidence Protection Function

80 FR 55221 - Special Conditions: Bombardier Aerospace Inc. Model BD-500-1A10 and BD-500-1A11 Airplanes; Flight-Envelope Protection, High Incidence Protection Function

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 178 (September 15, 2015)

Page Range55221-55225
FR Document2015-23101

These special conditions are issued for the Bombardier Aerospace Inc. Model BD-500-1A10 and -A11 airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology and design envisioned in the airworthiness standards for transport-category airplanes. This design feature is a high incidence protection system that limits the angle of attack at which the airplane can be flown during normal low-speed operation. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. 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.

Federal Register, Volume 80 Issue 178 (Tuesday, September 15, 2015)
[Federal Register Volume 80, Number 178 (Tuesday, September 15, 2015)]
[Rules and Regulations]
[Pages 55221-55225]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-23101]



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Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / 
Rules and Regulations

[[Page 55221]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2015-1940; Special Conditions No. 25-597-SC]


Special Conditions: Bombardier Aerospace Inc. Model BD-500-1A10 
and BD-500-1A11 Airplanes; Flight-Envelope Protection, High Incidence 
Protection Function

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions, request for comment.

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

SUMMARY: These special conditions are issued for the Bombardier 
Aerospace Inc. Model BD-500-1A10 and -A11 airplanes. These airplanes 
will have a novel or unusual design feature when compared to the state 
of technology and design envisioned in the airworthiness standards for 
transport-category airplanes. This design feature is a high incidence 
protection system that limits the angle of attack at which the airplane 
can be flown during normal low-speed operation. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for this design feature. 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: This action is effective on Bombardier Aerospace Inc. on 
September 15, 2015. We must receive your comments by October 30, 2015.

ADDRESSES: Send comments identified by docket number FAA-2015-1940 
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 or 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 9 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://www.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 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, Airplane and Flight 
Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone (425) 227-2011; facsimile (425) 227-
1149.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions is 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
airplanes.
    In addition, the substance of these special conditions has been 
subject to the public-comment process in several prior instances with 
no substantive comments received. The FAA therefore finds that good 
cause exists for making these special conditions effective upon 
publication in the Federal Register.

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 by the closing date for 
comments. We may change these special conditions based on the comments 
we receive.

Background

    On December 10, 2009, Bombardier Aerospace Inc. applied for a type 
certificate for their new Model BD-500-1A10 and -1A11 airplanes. The 
Model BD-500-1A10 and -1A11 airplanes are swept-wing monoplanes with a 
pressurized cabin, and share an identical supplier base and significant 
common design elements. The fuselage is aluminum alloy material, 
blended double-bubble fuselage, and is sized for nominal five-abreast 
seating. The powerplant for each airplane model includes two under-wing 
Pratt and Whitney PW1524G ultra-high bypass, geared turbofan engines. 
Flight controls are fly-by-wire with two passive/uncoupled side sticks. 
Avionics include five landscape primary flightdeck displays. The 
wingspans are 115 feet; heights are 37.75 feet; and length is 114.75 
feet for the Model BD-500-1A10, and 127 feet for the Model BD-500-1A11. 
Passenger capacity is 110 for the Model BD-500-1A10, and 125 for the 
Model BD-500-1A11. Maximum takeoff weight is 131,000 pounds for the 
Model BD-500-1A10, and 144,000 pounds for the Model BD-500-1A11. 
Maximum takeoff thrust is 21,000 pounds for the Model BD-500-1A10, and 
23,300 pounds for the Model BD-500-1A11. Range is 3,394 miles, and 
operating altitude is 41,000 feet, for both airplane models.
    Sections specified in these special conditions that address the 
high incidence protection system will replace common sections found in 
the applicable sections of Title 14, Code of Federal Regulations (14 
CFR) part 25.

[[Page 55222]]

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Bombardier Aerospace Inc. 
must show that the Model BD-500-1A10 and -1A11 airplanes meet the 
applicable provisions of part 25 as amended by Amendments 25-1 through 
25-129.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Model BD-500-1A10 and -1A11 
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, the Model BD-500-1A10 and -1A11 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 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).

Novel or Unusual Design Features

    The Model BD-500-1A10 and -1A11 airplanes will incorporate the 
following novel or unusual design feature:
    A high incidence protection system that replaces the stall warning 
system during normal operating conditions, prohibits the airplane from 
stalling, limits the angle of attack at which the airplane can be flown 
during normal low speed operation, and that cannot be overridden by the 
flightcrew. The application of this angle-of-attack limit impacts the 
stall-speed determination, the stall-characteristics and stall-warning 
demonstration, and the longitudinal-handling characteristics. The 
current regulations do not address this type of protection feature.

Discussion

    The high incidence protection function prevents the airplane from 
stalling at low speeds and, therefore, a stall-warning system is not 
needed during normal flight conditions. If a failure of the high 
incidence protection function occurs that is not shown to be extremely 
improbable, stall warning must be provided in a conventional manner. 
Also, the flight characteristics at the angle of attack for maximum-
lift coefficient (CLmax) must be suitable in the traditional 
sense.
    These special conditions address this novel or unusual design 
feature on the Bombardier Model BD-500-1A10 and -1A11 airplanes. These 
special conditions, which include airplane performance requirements, 
establish a level of safety equivalent to the current regulations for 
reference stall speeds, stall warning, stall characteristics, and 
miscellaneous other minimum reference speeds.
    These proposed special conditions for the Bombardier Model BD-500-
1A10 and -1A11 airplanes present amendments to the appropriate 
regulations to accommodate the unique features of the high incidence 
protection function.

Applicability

    As discussed above, these special conditions are applicable to the 
Bombardier Model BD-500-1A10 and -1A11 airplanes. Should Bombardier 
apply at a later date for a change to the type certificate to include 
another model incorporating the same or similar 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 one model of airplanes. 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

    Accordingly, the Federal Aviation Administration (FAA) issues the 
following special conditions as part of the type certification basis 
for Bombardier Model BD-500-1A10 and -1A11 airplanes.

Flight Envelope Protection: High Incidence Protection System

Special Conditions Part I

Stall Protection and Scheduled Operating Speeds

    The following special conditions are in lieu of Sec. Sec.  
25.21(b), 25.103, 25.145(a), 25.145(b)(6), 25.201, 25.203, 25.207, and 
25.1323(d).

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 use terminology that does not appear in 14 
CFR part 25:
     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 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 Part I, section 3 of these special conditions.
     Vmin 1g: Vmin corrected to 1g conditions. See 
Part I, section 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

    The applicant must establish the capability and reliability of the 
high incidence protection system. The applicant may establish this 
capability and reliability by flight test, simulation, or analysis. The 
capability and reliability required are:
    1. It must not be possible during pilot-induced maneuvers to 
encounter a stall, and handling characteristics must be acceptable, as 
required by Part I, section 5 of these special conditions.
    2. The airplane must be protected against stalling due to the 
effects of wind-shears and gusts at low speeds as required by Part I, 
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 are likely to be 
used in flight following system failures.

[[Page 55223]]

    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, the following applies:
    (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 automatic thrust system (if applicable) 
inhibited;
    (3) All combinations of flap settings and landing gear position for 
which Vmin is required to be determined;
    (4) The weight used when reference stall speed, 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 1-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 subparagraph (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] TR15SE15.002

    (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) Reserved.
    (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; and
    (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 apply:

4.1 Normal Operation

    If the design meets all conditions of section 2 of these special 
conditions, then the airplane need not provide stall warning during 
normal operation. The conditions of section 2 provide safety equivalent 
to Sec.  25.207, ``Stall warning,'' so the provision of an additional, 
unique warning device for normal operations is not required.

4.2 High Incidence Protection System Failure

    For any failure of the high incidence protection system that the 
applicant cannot show to be extremely improbable, and that result in 
the capability of the system no longer satisfying any part of section 2 
of these

[[Page 55224]]

special conditions, the design must provide stall warning that protects 
against encountering unacceptable stall characteristics and against 
encountering stall.
    (a) This 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) The design must also provide this stall warning in each 
abnormal configuration of the high-lift devices that is likely to be 
used in flight following system failures.
    (c) The design may furnish this stall warning either through the 
inherent aerodynamic qualities of the airplane or by a device that will 
give clearly distinguishable indications under all expected conditions 
of flight. However, a visual stall-warning device that requires the 
attention of the crew within the flightdeck 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 in paragraphs (d) and (e), below.
    (d) In non-icing conditions, stall warning must provide sufficient 
margin to prevent encountering unacceptable stall 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 calibrated airspeed, 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 a strong and 
effective deterrent to further speed reduction;
    (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 airplane 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 Sec. Sec.  25.201 and 25.203, the following apply:

5.1 High Incidence Handling Demonstration

    In lieu of Sec.  25.201:
    (a) Maneuvers to the limit of the longitudinal control, in the 
nose-up pitch, must be demonstrated in straight flight and in 30-degree 
banked turns with:
    (1) The high incidence protection system operating normally;
    (2) Initial power conditions of:
    i. Power off; and
    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) None.
    (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 1 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; and
    (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 3 knots per second.
    (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 requirements must also be met in 
deceleration at 1 knot per second up to full back stick.

5.2 Characteristics in High Incidence Maneuvers

    In lieu of Sec.  25.203:
    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-degree 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.
    (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 paragraph 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.
    (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

    In lieu of Sec.  25.201:
    (a) In non-icing conditions:
    Maneuvers with a rate of deceleration of not more than 1 knot per 
second, up

[[Page 55225]]

to the angle of attack at which VCLmax was obtained, as 
defined in section 3, ``Minimum Steady Flight Speed and Reference Stall 
Speed,'' must be demonstrated in straight flight and in 30-degree 
banked turns in the following configurations:
    (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 (if applicable);
    (3) Engines idling;
    (4) Flaps and landing gear in any likely combination of positions; 
and
    (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 
paragraph 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 (if applicable);
    (3) Engines idling;
    (4) Flaps and landing gear in any likely combination of positions; 
and
    (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 the 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 airplane 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. Proof of Compliance

    In lieu of Sec.  25.21(b), ``[Reserved],'' the design must meet the 
following requirement:
    (b) The flying qualities must be evaluated at the most unfavorable 
center-of-gravity position.

8. Sections 25.145(a), 25.145(b)(6), and 25.1323(d)

    The design must meet the following modified requirements:
     For Sec.  25.145(a), add ``Vmin'' in lieu of 
``stall identification.''
     For Sec.  25.145(b)(6), add ``Vmin'' in lieu of 
``VSW.''
     For Sec.  25.1323(d), add ``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

    The following special conditions are in lieu of the specified 
paragraphs of Sec. Sec.  25.103, 25.105, 25.107, 25.121, 25.123, 
25.125, 25.143, and 25.207.
    1. In lieu of Sec.  25.103, define the stall speed as provided in 
Part I of these special conditions.
    2. In lieu of Sec.  25.105(a)(2)(i), the following applies:
    (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 apply 25.105(a)(2)(ii) unchanged.
    3. In lieu of Sec.  25.107(c) and (g), the following apply, with 
additional sections (c') and (g'):
    (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 ``takeoff ice'' accretion defined 
in part 25, appendix C, V2 may not be less than--
    (1) The V2 speed determined in non-icing conditions; and
    (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 takeoff ice'' accretion 
defined in part 25, 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. Sec.  25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A), 
and 25.121(d)(2)(ii), the following apply:
    In lieu of Sec.  25.121(b)(2)(ii)(A):
    (A) 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
    In lieu of Sec.  25.121(c)(2)(ii)(A):
    (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):
    (d)(2) The requirements of subparagraph (d)(1) of this paragraph 
must be met:
    (ii) In icing conditions with the approach ice accretion defined in 
14 CFR part 25, appendix C, in a configuration corresponding to the 
normal all-engines-operating procedure in which Vmin1g for 
this configuration does not exceed 110 percent 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), the following applies:
    (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
    6. In lieu of Sec.  25.125(b)(2)(ii)(B) and Sec.  
25.125(b)(2)(ii)(C), the following applies:
    (B) A speed that provides the maneuvering capability specified in 
Sec.  25.143(h) with the approach ice accretion defined in 14 CFR part 
25, appendix C.
    7. In lieu of Sec.  25.143(j)(2)(i), the following applies:
    (i) The airplane is controllable in a pull-up maneuver up to 1.5 g 
load factor or lower if limited by angle-of-attack protection.
    8. In lieu of Sec.  25.207, ``Stall warning,'' to read as the 
requirements defined in these special conditions Part I, section 4.

    Issued in Renton, Washington, on September 1, 2015.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-23101 Filed 9-14-15; 8:45 am]
 BILLING CODE 4910-13-P



                                                                                                                                                                                                55221

                                                Rules and Regulations                                                                                         Federal Register
                                                                                                                                                              Vol. 80, No. 178

                                                                                                                                                              Tuesday, September 15, 2015



                                                This section of the FEDERAL REGISTER                       • Mail: Send comments to Docket                    comments received. The FAA therefore
                                                contains regulatory documents having general            Operations, M–30, U.S. Department of                  finds that good cause exists for making
                                                applicability and legal effect, most of which           Transportation (DOT), 1200 New Jersey                 these special conditions effective upon
                                                are keyed to and codified in the Code of                Avenue SE., Room W12–140, West                        publication in the Federal Register.
                                                Federal Regulations, which is published under           Building Ground Floor, Washington,
                                                50 titles pursuant to 44 U.S.C. 1510.                                                                         Comments Invited
                                                                                                        DC, 20590–0001.
                                                The Code of Federal Regulations is sold by                 • Hand Delivery or Courier: Take                     We invite interested people to take
                                                the Superintendent of Documents. Prices of              comments to Docket Operations in                      part in this rulemaking by sending
                                                new books are listed in the first FEDERAL               Room W12–140 of the West Building                     written comments, data, or views. The
                                                REGISTER issue of each week.                            Ground Floor at 1200 New Jersey                       most helpful comments reference a
                                                                                                        Avenue SE., Washington, DC, between 9                 specific portion of the special
                                                                                                        a.m. and 5 p.m., Monday through                       conditions, explain the reason for any
                                                DEPARTMENT OF TRANSPORTATION                            Friday, except Federal holidays.                      recommended change, and include
                                                                                                           • Fax: Fax comments to Docket                      supporting data.
                                                Federal Aviation Administration                         Operations at 202–493–2251.                             We will consider all comments we
                                                                                                           Privacy: The FAA will post all                     receive by the closing date for
                                                14 CFR Part 25                                          comments it receives, without change,                 comments. We may change these special
                                                [Docket No. FAA–2015–1940; Special                      to http://www.regulations.gov/,                       conditions based on the comments we
                                                Conditions No. 25–597–SC]                               including any personal information the                receive.
                                                                                                        commenter provides. Using the search
                                                Special Conditions: Bombardier                          function of the docket Web site, anyone               Background
                                                Aerospace Inc. Model BD–500–1A10                        can find and read the electronic form of                 On December 10, 2009, Bombardier
                                                and BD–500–1A11 Airplanes; Flight-                      all comments received into any FAA                    Aerospace Inc. applied for a type
                                                Envelope Protection, High Incidence                     docket, including the name of the                     certificate for their new Model BD–500-
                                                Protection Function                                     individual sending the comment (or                    1A10 and –1A11 airplanes. The Model
                                                AGENCY:  Federal Aviation                               signing the comment for an association,               BD–500–1A10 and –1A11 airplanes are
                                                Administration (FAA), DOT.                              business, labor union, etc.). DOT’s                   swept-wing monoplanes with a
                                                ACTION: Final special conditions, request
                                                                                                        complete Privacy Act Statement can be                 pressurized cabin, and share an
                                                for comment.                                            found in the Federal Register published               identical supplier base and significant
                                                                                                        on April 11, 2000 (65 FR 19477–19478),                common design elements. The fuselage
                                                SUMMARY:   These special conditions are                 as well as at http://DocketsInfo.dot                  is aluminum alloy material, blended
                                                issued for the Bombardier Aerospace                     .gov/.                                                double-bubble fuselage, and is sized for
                                                Inc. Model BD–500–1A10 and –A11                            Docket: Background documents or                    nominal five-abreast seating. The
                                                airplanes. These airplanes will have a                  comments received may be read at                      powerplant for each airplane model
                                                novel or unusual design feature when                    http://www.regulations.gov/ at any time.              includes two under-wing Pratt and
                                                compared to the state of technology and                 Follow the online instructions for                    Whitney PW1524G ultra-high bypass,
                                                design envisioned in the airworthiness                  accessing the docket or go to Docket                  geared turbofan engines. Flight controls
                                                standards for transport-category                        Operations in Room W12–140 of the                     are fly-by-wire with two passive/
                                                airplanes. This design feature is a high                West Building Ground Floor at 1200                    uncoupled side sticks. Avionics include
                                                incidence protection system that limits                 New Jersey Avenue SE., Washington,                    five landscape primary flightdeck
                                                the angle of attack at which the airplane               DC, between 9 a.m. and 5 p.m., Monday                 displays. The wingspans are 115 feet;
                                                can be flown during normal low-speed                    through Friday, except Federal holidays.              heights are 37.75 feet; and length is
                                                operation. The applicable airworthiness                 FOR FURTHER INFORMATION CONTACT: Joe                  114.75 feet for the Model BD–500–1A10,
                                                regulations do not contain adequate or                  Jacobsen, FAA, Airplane and Flight                    and 127 feet for the Model BD–500–
                                                appropriate safety standards for this                   Crew Interface Branch, ANM–111,                       1A11. Passenger capacity is 110 for the
                                                design feature. These special conditions                Transport Airplane Directorate, Aircraft              Model BD–500–1A10, and 125 for the
                                                contain the additional safety standards                 Certification Service, 1601 Lind Avenue               Model BD–500–1A11. Maximum takeoff
                                                that the Administrator considers                        SW., Renton, Washington 98057–3356;                   weight is 131,000 pounds for the Model
                                                necessary to establish a level of safety                telephone (425) 227–2011; facsimile                   BD–500–1A10, and 144,000 pounds for
                                                equivalent to that established by the                   (425) 227–1149.                                       the Model BD–500–1A11. Maximum
                                                existing airworthiness standards.                       SUPPLEMENTARY INFORMATION: The FAA                    takeoff thrust is 21,000 pounds for the
                                                DATES: This action is effective on                      has determined that notice of, and                    Model BD–500–1A10, and 23,300
                                                Bombardier Aerospace Inc. on                            opportunity for prior public comment                  pounds for the Model BD–500–1A11.
                                                September 15, 2015. We must receive                     on, these special conditions is                       Range is 3,394 miles, and operating
                                                your comments by October 30, 2015.                      impracticable because these procedures                altitude is 41,000 feet, for both airplane
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                                                ADDRESSES: Send comments identified                     would significantly delay issuance of                 models.
                                                by docket number FAA–2015–1940                          the design approval and thus delivery of                 Sections specified in these special
                                                using any of the following methods:                     the affected airplanes.                               conditions that address the high
                                                   • Federal eRegulations Portal: Go to                    In addition, the substance of these                incidence protection system will replace
                                                http://www.regulations.gov/ and follow                  special conditions has been subject to                common sections found in the
                                                the online instructions for sending your                the public-comment process in several                 applicable sections of Title 14, Code of
                                                comments electronically.                                prior instances with no substantive                   Federal Regulations (14 CFR) part 25.


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                                                55222            Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / Rules and Regulations

                                                Type Certification Basis                                failure of the high incidence protection              25.145(b)(6), 25.201, 25.203, 25.207, and
                                                   Under the provisions of 14 CFR 21.17,                function occurs that is not shown to be               25.1323(d).
                                                Bombardier Aerospace Inc. must show                     extremely improbable, stall warning
                                                                                                                                                              Foreword
                                                that the Model BD–500-1A10 and –1A11                    must be provided in a conventional
                                                                                                        manner. Also, the flight characteristics                In the following paragraphs, ‘‘in icing
                                                airplanes meet the applicable provisions
                                                                                                        at the angle of attack for maximum-lift               conditions’’ means with the ice
                                                of part 25 as amended by Amendments
                                                                                                        coefficient (CLmax) must be suitable in               accretions (relative to the relevant flight
                                                25–1 through 25–129.
                                                                                                        the traditional sense.                                phase) as defined in 14 CFR part 25,
                                                   If the Administrator finds that the
                                                                                                           These special conditions address this              Amendment 121, appendix C.
                                                applicable airworthiness regulations
                                                                                                        novel or unusual design feature on the                1. Definitions
                                                (i.e., 14 CFR part 25) do not contain
                                                                                                        Bombardier Model BD–500–1A10 and
                                                adequate or appropriate safety standards                                                                         These special conditions use
                                                                                                        –1A11 airplanes. These special
                                                for the Model BD–500–1A10 and –1A11                                                                           terminology that does not appear in 14
                                                                                                        conditions, which include airplane
                                                airplanes because of a novel or unusual                                                                       CFR part 25:
                                                                                                        performance requirements, establish a
                                                design feature, special conditions are                                                                           • High incidence protection system: A
                                                                                                        level of safety equivalent to the current
                                                prescribed under the provisions of                                                                            system that operates directly and
                                                                                                        regulations for reference stall speeds,
                                                § 21.16.                                                                                                      automatically on the airplane’s flying
                                                                                                        stall warning, stall characteristics, and
                                                   Special conditions are initially                                                                           controls to limit the maximum angle of
                                                                                                        miscellaneous other minimum reference
                                                applicable to the model for which they                                                                        attack that can be attained to a value
                                                                                                        speeds.
                                                are issued. Should the type certificate                                                                       below that at which an aerodynamic
                                                                                                           These proposed special conditions for
                                                for that model be amended later to                                                                            stall would occur.
                                                                                                        the Bombardier Model BD–500–1A10
                                                include any other model that
                                                                                                        and –1A11 airplanes present                              • Alpha limit: The maximum angle of
                                                incorporates the same or similar novel                                                                        attack at which the airplane stabilizes
                                                                                                        amendments to the appropriate
                                                or unusual design feature, the special                                                                        with the high incidence protection
                                                                                                        regulations to accommodate the unique
                                                conditions would also apply to the other                                                                      system operating, and the longitudinal
                                                                                                        features of the high incidence protection
                                                model under § 21.101.                                                                                         control held on its aft stop.
                                                                                                        function.
                                                   In addition to the applicable                                                                                 • Vmin: The minimum steady flight
                                                airworthiness regulations and special                   Applicability                                         speed in the airplane configuration
                                                conditions, the Model BD–500–1A10                         As discussed above, these special                   under consideration with the high
                                                and –1A11 airplanes must comply with                    conditions are applicable to the                      incidence protection system operating.
                                                the fuel-vent and exhaust-emission                      Bombardier Model BD–500–1A10 and                      See Part I, section 3 of these special
                                                requirements of 14 CFR part 34, and the                 –1A11 airplanes. Should Bombardier                    conditions.
                                                noise-certification requirements of 14                  apply at a later date for a change to the                • Vmin 1g: Vmin corrected to 1g
                                                CFR part 36; and the FAA must issue a                   type certificate to include another                   conditions. See Part I, section 3 of these
                                                finding of regulatory adequacy under                    model incorporating the same or similar               special conditions. It is the minimum
                                                § 611 of Public Law 92–574, the ‘‘Noise                 novel or unusual design feature, the                  calibrated airspeed at which the
                                                Control Act of 1972.’’                                  special conditions would apply to that                airplane can develop a lift force normal
                                                   The FAA issues special conditions, as                model as well.                                        to the flight path and equal to its weight
                                                defined in 14 CFR 11.19, in accordance                                                                        when at an angle of attack not greater
                                                with § 11.38, and they become part of                   Conclusion                                            than that determined for Vmin.
                                                the type certification basis under                        This action affects only certain novel
                                                § 21.17(a)(2).                                                                                                2. Capability and Reliability of the High
                                                                                                        or unusual design features on one model
                                                                                                                                                              Incidence Protection System
                                                Novel or Unusual Design Features                        of airplanes. It is not a rule of general
                                                                                                        applicability.                                           The applicant must establish the
                                                  The Model BD–500–1A10 and –1A11                                                                             capability and reliability of the high
                                                airplanes will incorporate the following                List of Subjects in 14 CFR Part 25                    incidence protection system. The
                                                novel or unusual design feature:                          Aircraft, Aviation safety, Reporting                applicant may establish this capability
                                                  A high incidence protection system                    and recordkeeping requirements.                       and reliability by flight test, simulation,
                                                that replaces the stall warning system                    The authority citation for these                    or analysis. The capability and
                                                during normal operating conditions,                     special conditions is as follows:                     reliability required are:
                                                prohibits the airplane from stalling,                                                                            1. It must not be possible during pilot-
                                                                                                          Authority: 49 U.S.C. 106(g), 40113, 44701,
                                                limits the angle of attack at which the                 44702, 44704.
                                                                                                                                                              induced maneuvers to encounter a stall,
                                                airplane can be flown during normal                                                                           and handling characteristics must be
                                                low speed operation, and that cannot be                 The Special Conditions                                acceptable, as required by Part I, section
                                                overridden by the flightcrew. The                         Accordingly, the Federal Aviation                   5 of these special conditions.
                                                application of this angle-of-attack limit               Administration (FAA) issues the                          2. The airplane must be protected
                                                impacts the stall-speed determination,                  following special conditions as part of               against stalling due to the effects of
                                                the stall-characteristics and stall-                    the type certification basis for                      wind-shears and gusts at low speeds as
                                                warning demonstration, and the                          Bombardier Model BD–500–1A10 and                      required by Part I, section 6 of these
                                                longitudinal-handling characteristics.                  –1A11 airplanes.                                      special conditions.
                                                The current regulations do not address                                                                           3. The ability of the high incidence
                                                this type of protection feature.                        Flight Envelope Protection: High                      protection system to accommodate any
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                                                                                                        Incidence Protection System                           reduction in stalling incidence must be
                                                Discussion                                                                                                    verified in icing conditions.
                                                                                                        Special Conditions Part I
                                                  The high incidence protection                                                                                  4. The high incidence protection
                                                function prevents the airplane from                     Stall Protection and Scheduled                        system must be provided in each
                                                stalling at low speeds and, therefore, a                Operating Speeds                                      abnormal configuration of the high-lift
                                                stall-warning system is not needed                        The following special conditions are                devices that are likely to be used in
                                                during normal flight conditions. If a                   in lieu of §§ 25.21(b), 25.103, 25.145(a),            flight following system failures.


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                                                                 Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / Rules and Regulations                                       55223

                                                  5. The reliability of the system and                     (1) The high incidence protection                  calibrated airspeed at which the
                                                the effects of failures must be acceptable              system operating normally;                            airplane can develop a lift force (normal
                                                in accordance with § 25.1309.                              (2) Idle thrust and automatic thrust               to the flight path) equal to its weight,
                                                                                                        system (if applicable) inhibited;                     while at an angle of attack not greater
                                                3. Minimum Steady Flight Speed and                         (3) All combinations of flap settings
                                                Reference Stall Speed                                                                                         than that at which the minimum steady
                                                                                                        and landing gear position for which Vmin              flight speed of subparagraph (a) was
                                                   In lieu of § 25.103, the following                   is required to be determined;                         determined. It must be determined in
                                                applies:                                                   (4) The weight used when reference
                                                   (a) The minimum steady flight speed,                                                                       icing and non-icing conditions.
                                                                                                        stall speed, VSR, is being used as a factor
                                                Vmin, is the final stabilized calibrated                to determine compliance with a                           (d) The reference stall speed, VSR, is
                                                airspeed obtained when the airplane is                  required performance standard;                        a calibrated airspeed defined by the
                                                decelerated until the longitudinal                         (5) The most unfavorable center of                 applicant. VSR may not be less than a 1g
                                                control is on its stop in such a way that               gravity allowable; and                                stall speed. VSR must be determined in
                                                the entry rate does not exceed 1 knot per                  (6) The airplane trimmed for straight              non-icing conditions and expressed as:
                                                second.                                                 flight at a speed achievable by the
                                                   (b) The minimum steady flight speed,                 automatic trim system.
                                                Vmin, must be determined in icing and                      (c) The 1-g minimum steady flight
                                                non-icing conditions with:                              speed, Vmin1g, is the minimum




                                                  (e) VCLmax is determined in non-icing                    (5) The airplane trimmed for straight              4.1 Normal Operation
                                                conditions with:                                        flight at a speed achievable by the                     If the design meets all conditions of
                                                  (1) Engines idling, or, if that resultant             automatic trim system, but not less than              section 2 of these special conditions,
                                                thrust causes an appreciable decrease in                1.13 VSR and not greater than 1.3 VSR;                then the airplane need not provide stall
                                                stall speed, not more than zero thrust at                  (6) Reserved.                                      warning during normal operation. The
                                                the stall speed;                                           (7) The high incidence protection                  conditions of section 2 provide safety
                                                                                                        system adjusted, at the option of the                 equivalent to § 25.207, ‘‘Stall warning,’’
                                                  (2) The airplane in other respects
                                                                                                        applicant, to allow higher incidence                  so the provision of an additional,
                                                (such as flaps and landing gear) in the
                                                                                                        than is possible with the normal                      unique warning device for normal
                                                condition existing in the test or
                                                                                                        production system; and                                operations is not required.
                                                performance standard in which VSR is
                                                being used;                                                (8) Starting from the stabilized trim
                                                                                                        condition, apply the longitudinal                     4.2 High Incidence Protection System
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                                                  (3) The weight used when VSR is                       control to decelerate the airplane so that            Failure
                                                being used as a factor to determine                     the speed reduction does not exceed 1                   For any failure of the high incidence
                                                compliance with a required                              knot per second.                                      protection system that the applicant
                                                performance standard;                                                                                         cannot show to be extremely
                                                                                                        4. Stall Warning
                                                  (4) The center of gravity position that                                                                     improbable, and that result in the
                                                results in the highest value of reference                 In lieu of § 25.207, the following                  capability of the system no longer
                                                                                                                                                                                                           ER15SE15.002</GPH>




                                                stall speed;                                            apply:                                                satisfying any part of section 2 of these


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                                                55224            Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / Rules and Regulations

                                                special conditions, the design must                     full aft for a short time before recovery             increased rates of entry to the incidence
                                                provide stall warning that protects                     is initiated.                                         limit, up to 3 knots per second.
                                                against encountering unacceptable stall                    (g) An airplane exhibits unacceptable                (4) Maneuver with ice accretion prior
                                                characteristics and against encountering                characteristics during straight or turning            to operation of the normal anti-ice
                                                stall.                                                  flight decelerations if it is not always              system. With the ice accretion prior to
                                                   (a) This stall warning, with the flaps               possible to produce and to correct roll               operation of the normal anti-ice system,
                                                and landing gear in any normal                          and yaw by unreversed use of aileron                  the requirements must also be met in
                                                position, must be clear and distinctive                 and rudder controls, or abnormal nose-                deceleration at 1 knot per second up to
                                                to the pilot and meet the requirements                  up pitching occurs.                                   full back stick.
                                                specified in paragraphs (d) and (e),
                                                                                                        5. Handling Characteristics at High                   5.2 Characteristics in High Incidence
                                                below.
                                                   (b) The design must also provide this                Incidence                                             Maneuvers
                                                stall warning in each abnormal                            In lieu of §§ 25.201 and 25.203, the                   In lieu of § 25.203:
                                                configuration of the high-lift devices                  following apply:                                         In icing and non-icing conditions:
                                                that is likely to be used in flight                                                                              (a) Throughout maneuvers with a rate
                                                                                                        5.1 High Incidence Handling                           of deceleration of not more than 1 knot
                                                following system failures.
                                                   (c) The design may furnish this stall                Demonstration                                         per second, both in straight flight and in
                                                warning either through the inherent                        In lieu of § 25.201:                               30-degree banked turns, the airplane’s
                                                aerodynamic qualities of the airplane or                   (a) Maneuvers to the limit of the                  characteristics must be as follows:
                                                by a device that will give clearly                      longitudinal control, in the nose-up                     (1) There must not be any abnormal
                                                distinguishable indications under all                   pitch, must be demonstrated in straight               nose-up pitching.
                                                expected conditions of flight. However,                 flight and in 30-degree banked turns                     (2) There must not be any
                                                a visual stall-warning device that                      with:                                                 uncommanded nose-down pitching,
                                                requires the attention of the crew within                  (1) The high incidence protection                  which would be indicative of stall.
                                                the flightdeck is not acceptable by itself.             system operating normally;                            However, reasonable attitude changes
                                                If a warning device is used, it must                       (2) Initial power conditions of:                   associated with stabilizing the incidence
                                                provide a warning in each of the                           i. Power off; and                                  at Alpha limit as the longitudinal
                                                airplane configurations prescribed in                      ii. The power necessary to maintain                control reaches the stop would be
                                                paragraph (a), above, and for the                       level flight at 1.5 VSR1, where VSR1 is the           acceptable.
                                                conditions prescribed in paragraphs (d)                 reference stall speed with flaps in                      (3) There must not be any
                                                and (e), below.                                         approach position, the landing gear                   uncommanded lateral or directional
                                                   (d) In non-icing conditions, stall                   retracted, and maximum landing                        motion, and the pilot must retain good
                                                warning must provide sufficient margin                  weight.                                               lateral and directional control, by
                                                to prevent encountering unacceptable                       (3) None.                                          conventional use of the controls,
                                                stall characteristics and encountering                     (4) Flaps, landing gear, and                       throughout the maneuver.
                                                stall in the following conditions:                      deceleration devices in any likely                       (4) The airplane must not exhibit
                                                   (1) In power-off straight deceleration               combination of positions;                             buffeting of a magnitude and severity
                                                not exceeding 1 knot per second to a                       (5) Representative weights within the              that would act as a deterrent from
                                                speed 5 knots or 5 percent calibrated                   range for which certification is                      completing the maneuver specified in
                                                airspeed, whichever is greater, below                   requested; and                                        paragraph 5.1(a).
                                                the warning onset.                                         (6) The airplane trimmed for straight                 (b) In maneuvers with increased rates
                                                   (2) In turning flight, stall deceleration            flight at a speed achievable by the                   of deceleration, some degradation of
                                                at entry rates up to 3 knots per second                 automatic trim system.                                characteristics is acceptable, associated
                                                when recovery is initiated not less than                   (b) The following procedures must be               with a transient excursion beyond the
                                                1 second after the warning onset.                       used to show compliance in non-icing                  stabilized Alpha limit. However, the
                                                   (e) In icing conditions, stall warning               and icing conditions:                                 airplane must not exhibit dangerous
                                                must provide sufficient margin to                          (1) Starting at a speed sufficiently               characteristics or characteristics that
                                                prevent encountering unacceptable                       above the minimum steady flight speed                 would deter the pilot from holding the
                                                characteristics and encountering stall, in              to ensure that a steady rate of speed                 longitudinal control on the stop for a
                                                power-off straight and turning flight                   reduction can be established, apply the               period of time appropriate to the
                                                decelerations not exceeding 1 knot per                  longitudinal control so that the speed                maneuver.
                                                second, when the pilot starts a recovery                reduction does not exceed 1 knot per                     (c) It must always be possible to
                                                maneuver not less than three seconds                    second until the control reaches the                  reduce incidence by conventional use of
                                                after the onset of stall warning.                       stop;                                                 the controls.
                                                   (f) An airplane is considered stalled                   (2) The longitudinal control must be                  (d) The rate at which the airplane can
                                                when the behavior of the airplane gives                 maintained at the stop until the airplane             be maneuvered from trim speeds
                                                the pilot a clear and distinctive                       has reached a stabilized flight condition             associated with scheduled operating
                                                indication of an acceptable nature that                 and must then be recovered by normal                  speeds such as V2 and VREF, up to Alpha
                                                the airplane is stalled. Acceptable                     recovery techniques;                                  limit, must not be unduly damped or be
                                                indications of a stall, occurring either                   (3) Maneuvers with increased                       significantly slower than can be
                                                individually or in combination, are:                    deceleration rates:                                   achieved on conventionally controlled
                                                   (1) A nose-down pitch that cannot be                    (i) In non-icing conditions, the                   transport airplanes.
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                                                readily arrested;                                       requirements must also be met with
                                                   (2) Buffeting, of a magnitude and                    increased rates of entry to the incidence             5.3 Characteristics Up to Maximum
                                                severity that is a strong and effective                 limit, up to the maximum rate                         Lift Angle of Attack
                                                deterrent to further speed reduction;                   achievable; and                                         In lieu of § 25.201:
                                                   (3) The pitch control reaches the aft                   (ii) In icing conditions, with the anti-             (a) In non-icing conditions:
                                                stop, and no further increase in pitch                  ice system working normally, the                        Maneuvers with a rate of deceleration
                                                attitude occurs when the control is held                requirements must also be met with                    of not more than 1 knot per second, up


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                                                                 Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / Rules and Regulations                                            55225

                                                to the angle of attack at which VCLmax                  8. Sections 25.145(a), 25.145(b)(6), and                 (1) The VFTO speed determined in
                                                was obtained, as defined in section 3,                  25.1323(d)                                            non-icing conditions.
                                                ‘‘Minimum Steady Flight Speed and                                                                                (2) A speed that provides the
                                                                                                           The design must meet the following
                                                Reference Stall Speed,’’ must be                                                                              maneuvering capability specified in
                                                                                                        modified requirements:
                                                demonstrated in straight flight and in                                                                        § 25.143(h).
                                                                                                           • For § 25.145(a), add ‘‘Vmin’’ in lieu
                                                30-degree banked turns in the following                                                                          4. In lieu of §§ 25.121(b)(2)(ii)(A),
                                                                                                        of ‘‘stall identification.’’
                                                configurations:                                                                                               25.121(c)(2)(ii)(A), and 25.121(d)(2)(ii),
                                                                                                           • For § 25.145(b)(6), add ‘‘Vmin’’ in
                                                   (1) The high incidence protection                                                                          the following apply:
                                                                                                        lieu of ‘‘VSW.’’                                         In lieu of § 25.121(b)(2)(ii)(A):
                                                deactivated or adjusted, at the option of                  • For § 25.1323(d), add ‘‘From 1.23
                                                the applicant, to allow higher incidence                                                                         (A) The V2 speed scheduled in non-
                                                                                                        VSR to Vmin . . .,’’ in lieu of ‘‘1.23 VSR            icing conditions does not provide the
                                                than is possible with the normal                        to stall warning speed . . .,’’ and, ‘‘. . .
                                                production system;                                                                                            maneuvering capability specified in
                                                                                                        speeds below Vmin . . .’’ in lieu of ‘‘. . .          § 25.143(h) for the takeoff configuration;
                                                   (2) Automatic thrust-increase system                 speeds below stall warning. . . .’’
                                                inhibited (if applicable);                                                                                    or
                                                                                                        Special Conditions Part II—Credit for                    In lieu of § 25.121(c)(2)(ii)(A):
                                                   (3) Engines idling;                                                                                           (A) The VFTO speed scheduled in non-
                                                   (4) Flaps and landing gear in any                    Robust Envelope Protection in Icing
                                                                                                        Conditions                                            icing conditions does not provide the
                                                likely combination of positions; and                                                                          maneuvering capability specified in
                                                   (5) The airplane trimmed for straight                   The following special conditions are               § 25.143(h) for the en-route
                                                flight at a speed achievable by the                     in lieu of the specified paragraphs of                configuration; or
                                                automatic trim system.                                  §§ 25.103, 25.105, 25.107, 25.121,                       In lieu of § 25.121(d)(2)(ii):
                                                   (b) In icing conditions:                             25.123, 25.125, 25.143, and 25.207.                      (d)(2) The requirements of
                                                   Maneuvers with a rate of deceleration                   1. In lieu of § 25.103, define the stall           subparagraph (d)(1) of this paragraph
                                                of not more than 1 knot per second, up                  speed as provided in Part I of these                  must be met:
                                                to the maximum angle of attack reached                  special conditions.                                      (ii) In icing conditions with the
                                                during maneuvers from paragraph                            2. In lieu of § 25.105(a)(2)(i), the               approach ice accretion defined in 14
                                                5.1(b)(3)(ii), must be demonstrated in                  following applies:                                    CFR part 25, appendix C, in a
                                                straight flight with:                                      (i) The V2 speed scheduled in non-                 configuration corresponding to the
                                                   (1) The high incidence protection                    icing conditions does not provide the                 normal all-engines-operating procedure
                                                deactivated or adjusted, at the option of               maneuvering capability specified in                   in which Vmin1g for this configuration
                                                the applicant, to allow higher incidence                § 25.143(h) for the takeoff configuration,            does not exceed 110 percent of the
                                                than is possible with the normal                        or apply 25.105(a)(2)(ii) unchanged.                  Vmin1g for the related all-engines-
                                                production system;                                         3. In lieu of § 25.107(c) and (g), the             operating landing configuration in icing,
                                                   (2) Automatic thrust-increase system                 following apply, with additional                      with a climb speed established with
                                                inhibited (if applicable);                              sections (c′) and (g′):                               normal landing procedures, but not
                                                   (3) Engines idling;                                     (c) In non-icing conditions, V2, in                more than 1.4 VSR (VSR determined in
                                                   (4) Flaps and landing gear in any                    terms of calibrated airspeed, must be                 non-icing conditions).
                                                likely combination of positions; and                    selected by the applicant to provide at                  5. In lieu of § 25.123(b)(2)(i), the
                                                   (5) The airplane trimmed for straight                least the gradient of climb required by               following applies:
                                                flight at a speed achievable by the                     § 25.121(b), but may not be less than—                   (i) The minimum en-route speed
                                                automatic trim system.                                     (1) V2MIN;                                         scheduled in non-icing conditions does
                                                   (c) During the maneuvers used to                        (2) VR plus the speed increment                    not provide the maneuvering capability
                                                show compliance with paragraphs (a)                     attained (in accordance with                          specified in § 25.143(h) for the en-route
                                                and (b), above, the airplane must not                   § 25.111(c)(2)) before reaching a height              configuration, or
                                                exhibit dangerous characteristics, and it               of 35 feet above the takeoff surface; and                6. In lieu of § 25.125(b)(2)(ii)(B) and
                                                must always be possible to reduce the                      (3) A speed that provides the                      § 25.125(b)(2)(ii)(C), the following
                                                angle of attack by conventional use of                  maneuvering capability specified in                   applies:
                                                the controls. The pilot must retain good                § 25.143(h).                                             (B) A speed that provides the
                                                lateral and directional control, by                        (c′) In icing conditions with the                  maneuvering capability specified in
                                                conventional use of the controls,                       ‘‘takeoff ice’’ accretion defined in part             § 25.143(h) with the approach ice
                                                throughout the maneuver.                                25, appendix C, V2 may not be less                    accretion defined in 14 CFR part 25,
                                                                                                        than—                                                 appendix C.
                                                6. Atmospheric Disturbances                                (1) The V2 speed determined in non-                   7. In lieu of § 25.143(j)(2)(i), the
                                                   Operation of the high incidence                      icing conditions; and                                 following applies:
                                                                                                           (2) A speed that provides the                         (i) The airplane is controllable in a
                                                protection system must not adversely
                                                                                                        maneuvering capability specified in                   pull-up maneuver up to 1.5 g load factor
                                                affect airplane control during expected
                                                                                                        § 25.143(h).                                          or lower if limited by angle-of-attack
                                                levels of atmospheric disturbances, nor
                                                                                                           (g) In non-icing conditions, VFTO, in              protection.
                                                impede the application of recovery
                                                                                                                                                                 8. In lieu of § 25.207, ‘‘Stall warning,’’
                                                procedures in case of wind-shear. This                  terms of calibrated airspeed, must be
                                                                                                                                                              to read as the requirements defined in
                                                must be demonstrated in non-icing and                   selected by the applicant to provide at
                                                                                                                                                              these special conditions Part I, section
                                                icing conditions.                                       least the gradient of climb required by
                                                                                                                                                              4.
                                                                                                        § 25.121(c), but may not be less than—
mstockstill on DSK4VPTVN1PROD with RULES




                                                7. Proof of Compliance                                     (1) 1.18 VSR; and                                    Issued in Renton, Washington, on
                                                  In lieu of § 25.21(b), ‘‘[Reserved],’’ the               (2) A speed that provides the                      September 1, 2015.
                                                design must meet the following                          maneuvering capability specified in                   Michael Kaszycki,
                                                requirement:                                            § 25.143(h).                                          Acting Manager, Transport Airplane
                                                  (b) The flying qualities must be                         (g′) In icing conditions with the ‘‘final          Directorate, Aircraft Certification Service.
                                                evaluated at the most unfavorable                       takeoff ice’’ accretion defined in part 25,           [FR Doc. 2015–23101 Filed 9–14–15; 8:45 am]
                                                center-of-gravity position.                             appendix C, VFTO may not be less than—                BILLING CODE 4910–13–P




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Document Created: 2015-12-15 10:10:00
Document Modified: 2015-12-15 10:10:00
CategoryRegulatory Information
CollectionFederal Register
sudoc ClassAE 2.7:
GS 4.107:
AE 2.106:
PublisherOffice of the Federal Register, National Archives and Records Administration
SectionRules and Regulations
ActionFinal special conditions, request for comment.
DatesThis action is effective on Bombardier Aerospace Inc. on September 15, 2015. We must receive your comments by October 30, 2015.
ContactJoe Jacobsen, FAA, Airplane and Flight Crew Interface Branch, ANM-111, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 227-2011; facsimile (425) 227- 1149.
FR Citation80 FR 55221 
CFR AssociatedAircraft; Aviation Safety and Reporting and Recordkeeping Requirements

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