
[Federal Register Volume 82, Number 51 (Friday, March 17, 2017)]
[Rules and Regulations]
[Pages 14126-14128]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-05327]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2016-9296; Special Conditions No. 25-647-SC]


Special Conditions: Bombardier Inc., Model BD-700-2A12 and BD-
700-2A13 Series Airplanes, Electronic Flight Control System: Lateral-
Directional and Longitudinal Stability, and Low-Energy Awareness

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Bombardier Inc. 
(Bombardier) Model BD-700-2A12 and BD-700-2A13 series airplanes. These 
airplanes will have a novel or unusual design feature when compared to 
the state of technology envisioned in the airworthiness standards for 
transport-category airplanes. This design feature is lateral-
directional and longitudinal stability, and low-energy awareness, 
provided through an electronic flight-control system (EFCS). 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 on March 17, 2017. We 
must receive your comments by May 1, 2017.

ADDRESSES: Send comments identified by docket number FAA-2016-9296 
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,

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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 
Flightcrew Interface, ANM-111, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2011; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: 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 May 30, 2012, Bombardier applied for an amendment to Type 
Certificate No. T00003NY to include the new Model BD-700-2A12 and BD-
700-2A13 series airplanes. The Model BD-700-2A12 and BD-700-2A13 series 
airplanes, which are derivatives of the BD-700 currently approved under 
Type Certificate No. T00003NY, are ultra-long-range, executive-interior 
business jets, with a passenger capacity of 19.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.101, Bombardier must show that the Model BD-700-2A12 and BD-
700-2A13 series airplanes meet the applicable provisions of the 
regulations listed in Type Certificate No. T00003NY, or the applicable 
regulations in effect on the date of application for the change, except 
for earlier amendments as agreed upon by the FAA.
    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 Bombardier Model BD-700-2A12 and 
BD-700-2A13 series airplanes because of a novel or unusual design 
feature, special conditions are prescribed under the provisions of 
Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same novel or 
unusual design feature, or should any other model already included on 
the same type certificate be modified to incorporate the same novel or 
unusual design feature, these special conditions would also apply to 
the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Bombardier Model BD-700-2A12 and BD-700-2A13 series 
airplanes must comply with the fuel-vent and exhaust-emission 
requirements of 14 CFR part 34 and the noise-certification requirements 
of 14 CFR part 36.
    The FAA 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.  21.101.

Novel or Unusual Design Features

    The Bombardier Model BD-700-2A12 and BD-700-2A13 series airplanes 
will incorporate the following novel or unusual design feature:
    Lateral-directional and longitudinal stability, and low-energy 
awareness, through an electronic flight-control system.

Discussion

    The EFCS on the Bombardier Model BD-700-2A12 and BD-700-2A13 series 
airplanes contain fly-by-wire control laws that can impact static 
stability; therefore, the conventional requirements in the regulations 
are not always met.
    Positive static-directional stability is defined as the tendency to 
recover from a skid with the rudder free. Positive static-lateral 
stability is defined as the tendency to raise the low wing in a 
sideslip with the aileron controls free. These control criteria are 
intended to accomplish the following:
     Provide additional cues of inadvertent sideslips and skids 
through control-force changes.
     Ensure that short periods of unattended operation do not 
result in any significant changes in yaw or bank angle.
     Provide predictable roll and yaw response.
     Provide an acceptable level of pilot attention (workload) 
to attain and maintain a coordinated turn.
    Static longitudinal stability on airplanes with mechanical links to 
the pitch-control surface means that a pull force on the controller 
results in a reduction in speed relative to the trim speed, and a push 
force on the controller results in higher than trim speed. Longitudinal 
stability is required by the regulations for the following reasons:
     Speed change cues are provided to the pilot through 
increased and decreased forces on the controller.
     Short periods of unattended control of the airplane do not 
result in significant changes in attitude, airspeed, or load factor.
     A predictable pitch response is provided to the pilot.
     An acceptable level of pilot attention (workload) to 
attain and maintain trim speed and altitude is provided to the pilot.
     Longitudinal stability provides gust stability.
    Past experience on airplanes fitted with a flight-control system 
providing neutral longitudinal stability reveals insufficient feedback 
cues to the pilot for excursion below normal operational speeds. The 
maximum angle-of-attack protection system limits the airplane angle of 
attack and prevents stall during normal operating speeds, but this 
system is not sufficient to prevent stall at low-speed excursions below 
normal operational speeds. Until intervention, the pilot receives no 
stability cues because the airplane remains trimmed. Additionally, due 
to thrust variation,

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flight-control laws reduce feedback from the pitching moment. Low-speed 
excursions may become more hazardous without the typical longitudinal 
stability, and recovery may become more difficult when the low-speed 
situation is associated with a low altitude, and with the engines at 
low thrust or in performance-limiting conditions.
    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.

Applicability

    As discussed above, these special conditions are applicable to 
Bombardier Model BD-700-2A12 and BD-700-2A13 series airplanes. Should 
Bombardier apply at a later date for a change to the type certificate 
to include another model incorporating the same novel or unusual design 
feature, these special conditions would apply to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on Bombardier Model BD-700-2A12 and BD-700-2A13 series airplanes. It is 
not a rule of general applicability.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, because a delay would 
significantly affect the certification of the airplane, the FAA has 
determined that prior public notice and comment are unnecessary and 
impracticable, and good cause exists for adopting these special 
conditions upon publication in the Federal Register.
    The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment described above.

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, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Bombardier Inc. Model BD-700-2A12 and 
BD-700-2A13 series airplanes.
    In lieu of the requirements of Sec. Sec.  25.171, 25.173, 25.175 
and 25.177(c), the following special conditions apply:
    1. The airplane must be shown to have suitable static lateral, 
directional, and longitudinal stability in any condition normally 
encountered in service, including from the effects of atmospheric 
disturbance. The showing of suitable static lateral, directional, and 
longitudinal stability must be based on the airplane handling 
qualities, including pilot workload and pilot compensation, for 
specific test procedures during the flight-test evaluations.
    2. The airplane must provide to the pilot adequate awareness of a 
low-energy (low speed, low thrust, low height) state when fitted with 
flight-control laws presenting neutral longitudinal stability 
significantly below the normal operating speeds. ``Adequate awareness'' 
means warning information that alerts the flightcrew of unsafe 
operating conditions, allowing the flightcrew to take appropriate 
corrective action.
    3. The following requirement must be met for the configurations and 
speed specified in paragraph (a) of Sec.  25.177. In straight, steady 
sideslips over the range of sideslip angles appropriate to the 
operation of the airplane, the rudder-control movements and forces must 
be substantially proportional to the angle of sideslip in a stable 
sense. This factor of proportionality must lie between limits found 
necessary for safe operation. The range of sideslip angles evaluated 
must include those sideslip angles resulting from the lesser of:
    a. One-half of the available rudder-control input; and
    b. A rudder-control force of 180 pounds.

    Issued in Renton, Washington, on February 10, 2017.
Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. 2017-05327 Filed 3-16-17; 8:45 am]
BILLING CODE 4910-13-P


