80 FR 10632 - Special Conditions: Bombardier Aerospace Incorporated, Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Electronic Flight Control System: Pitch and Roll Limiting Functions

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 39 (February 27, 2015)

This action proposes special conditions for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 Series Airplanes. These airplanes will have a novel or unusual design feature associated with the fly-by-wire electronic flight control system (EFCS) that limits pitch- and roll-attitude functions to prevent the airplane from attaining certain pitch attitudes and roll angles. This system generates the actual surface commands that provide for stability augmentation and flight control for all three-airplane axes (longitudinal, lateral, and directional). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

[Federal Register Volume 80, Number 39 (Friday, February 27, 2015)]
[Proposed Rules]
[Pages 10632-10633]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-04050]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No.FAA-2015-0426; Notice No. 25-15-03-SC]


Special Conditions: Bombardier Aerospace Incorporated, Models BD-
500-1A10 and BD-500-1A11 Series Airplanes; Electronic Flight Control 
System: Pitch and Roll Limiting Functions

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This action proposes special conditions for the Bombardier 
Aerospace Models BD-500-1A10 and BD-500-1A11 Series Airplanes. These 
airplanes will have a novel or unusual design feature associated with 
the fly-by-wire electronic flight control system (EFCS) that limits 
pitch- and roll-attitude functions to prevent the airplane from 
attaining certain pitch attitudes and roll angles. This system 
generates the actual surface commands that provide for stability 
augmentation and flight control for all three-airplane axes 
(longitudinal, lateral, and directional). The applicable airworthiness 
regulations do not contain adequate or appropriate safety standards for 
this design feature. These proposed special conditions contain the 
additional safety standards that the Administrator considers necessary 
to establish a level of safety equivalent to that established by the 
existing airworthiness standards.

DATES: Send your comments on or before April 13, 2015.

ADDRESSES: Send comments identified by docket number FAA-2015-0426 
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 the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Standardization 
Branch, ANM-113 Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone 
425-227-2011; facsimile 425-227-1149.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive 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 applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes (hereafter collectively referred to as ``CSeries''). The 
CSeries airplanes are swept-wing monoplanes with an aluminum alloy 
fuselage, sized for 5-abreast seating. Passenger capacity is designated 
as 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. The CSeries airplanes will 
have a fly-by-wire EFCS.

[[Page 10633]]

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Bombardier Aerospace must show that the CSeries airplane 
meets 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 Bombardier CSeries 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, 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 CSeries airplane 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 Bombardier CSeries airplane will incorporate the following 
novel or unusual design feature: Fly-by-wire EFCS that will limit pitch 
and roll attitude functions to prevent the airplane from attaining 
certain pitch attitudes and roll angles greater than plus or minus 65 
degrees, and positive spiral stability introduced for roll angles 
greater than 30 degrees at speeds below VMO/MMO. 
This system generates the actual surface commands that provide for 
stability augmentation and flight control for all three-airplane axes 
(longitudinal, lateral, and directional).

Discussion

    Part 25 does not specifically relate to flight characteristics 
associated with fixed attitude limits. Bombardier proposes on the 
CSeries to implement pitch and roll attitude-limiting functions via the 
EFCS normal mode. This will prevent the airplane from attaining certain 
pitch attitudes and roll angles greater than plus or minus 65 degrees. 
In addition, positive spiral stability, introduced for roll angles 
greater than 30 degrees at speeds below VMO/MMO, 
and spiral stability characteristics must not require excessive pilot 
strength to achieve bank angles up to the bank angle limit.
    These proposed special conditions contain the additional safety 
standards that the Administrator considers necessary to establish a 
level of safety equivalent to that established by the existing 
airworthiness standards.

Applicability

    As discussed above, these special conditions are applicable to the 
Bombardier CSeries airplane. Should Bombardier Aerospace apply later 
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 certain novel or unusual design features 
on Bombardier CSeries 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 Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for the Bombardier CSeries airplanes.
    In addition to Sec.  25.143, the following requirements apply to 
the EFCS pitch and roll limiting functions:
    1. The pitch limiting function must not impede normal maneuvering 
for pitch angles up to the maximum required for normal maneuvering, 
including a normal all-engines operating takeoff, plus a suitable 
margin to allow for satisfactory speed control.
    2. The pitch and roll limiting functions must not restrict or 
prevent attaining pitch attitudes necessary for emergency maneuvering 
or roll angles up to 65 degrees. Spiral stability, which is introduced 
above 30 degrees roll angle, must not require excessive pilot strength 
to achieve these roll angles. Other protections, which further limit 
the roll capability under certain extreme angle-of-attack, attitude, or 
high-speed conditions, are acceptable, as long as they allow at least 
45 degrees of roll capability.
    3. A lower limit of roll is acceptable beyond the overspeed warning 
if it is possible to recover the airplane to the normal flight envelope 
without undue difficulty or delay.

    Issued in Renton, Washington, on February 19, 2015.
John P. Piccola, Jr.,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-04050 Filed 2-26-15; 8:45 am]
BILLING CODE 4910-13-P