[Federal Register Volume 80, Number 122 (Thursday, June 25, 2015)]
[Rules and Regulations]
[Pages 36470-36471]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-15545]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2015-0426; Special Conditions No. 25-576-SC]
Special Conditions: Bombardier Aerospace Incorporated, Models BD-
500-1A10 and BD-500-1A11 Series Airplanes; Electronic Flight-Control
System (EFCS): Pitch-and Roll-Limiting Functions
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the Bombardier
Aerospace Model BD-500-1A10 and BD-500-1A11 series airplanes. These
airplanes will have a novel or unusual design feature associated with a
fly-by-wire EFCS that limits pitch- and roll-limiting 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 special conditions contain the
additional safety standards that the Administrator considers necessary
to establish a level of safety equivalent to that established by the
existing airworthiness standards.
DATES: Effective July 27, 2015.
FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Standardization
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:
Background
On December 10, 2009, Bombardier Aerospace applied for a type
certificate for their new Model BD-500-1A10 and
[[Page 36471]]
BD-500-1A11 series airplanes (hereafter collectively referred to as
``CSeries''). Bombardier later applied for, and was granted, an
extension of time for the type certificate, which changed the effective
application date to December 31, 2011. The CSeries airplanes are swept-
wing monoplanes with an aluminum alloy fuselage, sized for 5-abreast
seating. Passenger capacity is 110 for the Model BD-500-1A10 and 125
for the Model BD-500-1A11. The airplanes are powered by two underwing
Pratt and Whitney PW1524G ultra-high bypass, geared, turbofan engines.
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.
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. 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 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 to implement
on the CSeries airplanes 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 special conditions contain the additional safety standards
that the Administrator considers necessary to establish a level of
safety equivalent to that established by the existing airworthiness
standards.
Discussion of Comments
Notice of proposed special conditions no. 25-15-02-SC for the
Bombardier Model BD-500-1A10 and BD-500-1A11 series airplanes was
published in the Federal Register on February 27, 2015 (80 FR 10632).
No substantive comments were received, and the special conditions are
adopted as proposed.
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 or similar 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 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 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 June 17, 2015.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2015-15545 Filed 6-24-15; 8:45 am]
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