Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Flight Envelope Protection: Normal Load Factor (g) Limiting, 32636-32637 [2014-13241]
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32636
Federal Register / Vol. 79, No. 109 / Friday, June 6, 2014 / Rules and Regulations
Electronic Flight Control System:
Control Surface Awareness and Mode
Annunciation
1. In addition to the requirements of
§§ 25.143, 25.671, and 25.672, the
following requirements apply:
a. The system design must ensure that
the flightcrew is made suitably aware
whenever the primary control means
nears the limit of control authority.
■
Note: The term ‘‘suitably aware’’ indicates
annunciations provided to the flightcrew are
appropriately balanced between nuisance
and that necessary for crew awareness.
b. If the design of the flight control
system has multiple modes of operation,
a means must be provided to indicate to
the flightcrew any mode that
significantly changes or degrades the
normal handling or operational
characteristics of the airplane.
Issued in Renton, Washington, on April 22,
2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 2014–13240 Filed 6–5–14; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA–2013–1039; Notice No. 25–
547–SC]
Special Conditions: Bombardier
Aerospace, Models BD–500–1A10 and
BD–500–1A11 Series Airplanes; Flight
Envelope Protection: Normal Load
Factor (g) Limiting
Federal Aviation
Administration (FAA), DOT.
ACTION: Final Special Conditions.
AGENCY:
These special conditions are
issued 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 an electronic
flight control system that prevents the
pilot from inadvertently or intentionally
exceeding the positive or negative
airplane limit load factor. 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 Date: July 7, 2014.
mstockstill on DSK4VPTVN1PROD with RULES
SUMMARY:
VerDate Mar<15>2010
13:35 Jun 05, 2014
Jkt 232001
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:
requirements of 14 CFR part 36, and the
FAA must issue a finding of regulatory
adequacy under § 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 § 11.38, and they become part of
the type-certification basis under
§ 21.17(a)(2).
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 design of the electronic flight
control system for the CSeries airplanes
incorporates normal load factor limiting
on a full time basis that prevents the
flightcrew from inadvertently or
intentionally exceeding the positive or
negative airplane limit load factor. This
feature is considered novel and unusual
in that the current regulations do not
provide standards for maneuverability
and controllability evaluations for such
systems.
Novel or Unusual Design Features
Type Certification Basis
Under the provisions of Title 14, Code
of Federal Regulations (14 CFR) 21.17,
Bombardier Aerospace must show that
the CSeries airplanes meet the
applicable provisions of part 25 as
amended by Amendments 25–1 through
25–129 thereto.
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 CSeries airplanes because of a
novel or unusual design feature, special
conditions are prescribed under the
provisions of § 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 § 21.101.
In addition to the applicable
airworthiness regulations and special
conditions, the CSeries airplanes must
comply with the fuel vent and exhaust
emission requirements of 14 CFR part
34 and the noise certification
PO 00000
Frm 00004
Fmt 4700
Sfmt 4700
The CSeries airplanes will use a flyby-wire electronic flight control system
(EFCS). This system provides an
electronic interface between the pilot’s
flight controls and the flight control
surfaces for both normal and failure
states; and it generates the actual surface
commands that provide for stability
augmentation and control about all
three airplane axes.
The design of the EFCS incorporates
the following novel or unusual design
feature: Normal load factor limiting on
a full-time basis that will prevent the
flight crew from inadvertently or
intentionally exceeding the positive or
negative airplane limit load factor. This
feature is considered novel or unusual
because the current regulations do not
provide standards for maneuverability
and controllability evaluations for such
systems. Therefore, special conditions
are needed to ensure adequate
maneuverability and controllability
when using this design feature.
Discussion
Title 14, Code of Federal Regulations,
part 25 does not specify requirements or
policy for demonstrating maneuver
control that impose any handling
qualities requirements beyond the
design limit structural loads.
Nevertheless, some pilots have become
accustomed to the availability of this
excess maneuver capacity in case of
extreme emergency such as upset
recoveries or collision avoidance.
As with previous fly-by-wire
airplanes, the FAA has no regulatory or
safety reason to prohibit a design for an
electronic flight control system with
load factor limiting. It is possible that
pilots accustomed to this feature feel
more freedom in commanding full-stick
displacement maneuvers because of the
following:
• Knowledge that the limit system
will protect the structure,
• Low stick force/displacement
gradients,
• Smooth transition from pilot
elevator control to limit control.
These special conditions will ensure
adequate maneuverability and
controllability when using this design
feature.
E:\FR\FM\06JNR1.SGM
06JNR1
Federal Register / Vol. 79, No. 109 / Friday, June 6, 2014 / Rules and Regulations
The normal load factor limit on the
CSeries airplanes is unique in that
traditional airplanes with conventional
flight control systems (mechanical
linkages) are limited in the pitch axis
only by the elevator surface area and
deflection limit. The elevator control
power is normally derived for adequate
controllability and maneuverability at
the most critical longitudinal pitching
moment. The result is that traditional
airplanes have a significant portion of
the flight envelope wherein
maneuverability in excess of limit
structural design values is possible.
These special conditions for the
CSeries airplanes supplement the
applicable regulations, including
§ 25.143, to accommodate the unique
features of the flight envelope limiting
systems, and establish an equivalent
level of safety to the existing
regulations.
Discussion of Comments
Notice of proposed special conditions
No. 25–13–38–SC for the Bombardier
CSeries airplanes was published in the
Federal Register on December 11, 2013
(78 FR 75285). No comments were
received, and the special conditions are
adopted as proposed.
Applicability
As discussed above, these special
conditions are applicable to the Models
BD–500–1A10 and BD–500–1A11 series
airplanes. Should Bombardier
Aerospace apply at a later date for a
change to the type certificate to include
another model incorporating the same
novel or unusual design feature, the
special conditions would apply to that
model as well.
Conclusion
This action affects only certain novel
or unusual design features on two
model series 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.
mstockstill on DSK4VPTVN1PROD with RULES
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
Aerospace Models BD–500–1A10 and
BD–500–1A11 series airplanes.
VerDate Mar<15>2010
13:35 Jun 05, 2014
Jkt 232001
Flight Envelope Protection: Normal
Load Factor (g) Limiting
1. To meet the intent of adequate
maneuverability and controllability
required by § 25.143(a), and in addition
to the requirements of § 25.143(a) and in
the absence of other limiting factors, the
following special conditions based on
§ 25.333(b) apply:
a. The positive limiting load factor
must not be less than:
(1) 2.5g for the normal state of the
electronic flight control system with the
high lift devices retracted.
(2) 2.0g for the normal state of the
electronic flight control system with the
high lift devices extended.
b. The negative limiting load factor
must be equal to or more negative than:
(1) Minus 1.0g for the normal state of
the electronic flight control system with
the high lift devices retracted.
(2) 0.0g for the normal state of the
electronic flight control system with
high lift devices extended.
c. Maximum reachable positive load
factor wings level may be limited by the
characteristics of the electronic flight
control system or flight envelope
protections (other than load factor
protection) provided that:
(1) The required values are readily
achievable in turns, and
(2) That wings level pitch up is
satisfactory.
d. Maximum achievable negative load
factor may be limited by the
characteristics of the electronic flight
control system or flight envelope
protections (other than load factor
protection) provided that:
(1) Pitch down responsiveness is
satisfactory, and
(2) From level flight, 0g is readily
achievable or alternatively, a
satisfactory trajectory change is readily
achievable at operational speeds. For
the FAA to consider a trajectory change
as satisfactory, the applicant should
propose and justify a pitch rate that
provides sufficient maneuvering
capability in the most critical scenarios.
e. Compliance demonstration with the
above requirements may be performed
without ice accretion on the airframe.
These special conditions do not
impose an upper bound for the normal
load factor limit, nor do they require
that the limit exist. If the limit is set at
a value beyond the structural design
limit maneuvering load factor ‘‘n’’ of
§§ 25.333(b) and 25.337(b) and (c), there
should be a very obvious positive tactile
feel built into the controller so that it
serves as a deterrent to inadvertently
exceeding the structural limit.
■
PO 00000
Frm 00005
Fmt 4700
Sfmt 4700
32637
Issued in Renton, Washington, on April 22,
2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 2014–13241 Filed 6–5–14; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA–2013–1040; Notice No. 25–
548–SC]
Special Conditions: Bombardier
Aerospace, Models BD–500–1A10 and
BD–500–1A11 Series Airplanes; Flight
Envelope Protection: General Limiting
Requirements
Federal Aviation
Administration (FAA), DOT.
ACTION: Final Special Conditions.
AGENCY:
These special conditions are
issued 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 a new control
architecture and a full digital flight
control system that provides flight
envelope protections. 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 Date: July 7, 2014.
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:
SUMMARY:
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
E:\FR\FM\06JNR1.SGM
06JNR1
Agencies
[Federal Register Volume 79, Number 109 (Friday, June 6, 2014)]
[Rules and Regulations]
[Pages 32636-32637]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-13241]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2013-1039; Notice No. 25-547-SC]
Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and
BD-500-1A11 Series Airplanes; Flight Envelope Protection: Normal Load
Factor (g) Limiting
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final Special Conditions.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued 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
an electronic flight control system that prevents the pilot from
inadvertently or intentionally exceeding the positive or negative
airplane limit load factor. 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 Date: July 7, 2014.
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:
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 design of the electronic flight control system for the CSeries
airplanes incorporates normal load factor limiting on a full time basis
that prevents the flightcrew from inadvertently or intentionally
exceeding the positive or negative airplane limit load factor. This
feature is considered novel and unusual in that the current regulations
do not provide standards for maneuverability and controllability
evaluations for such systems.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulations (14
CFR) 21.17, Bombardier Aerospace must show that the CSeries airplanes
meet the applicable provisions of part 25 as amended by Amendments 25-1
through 25-129 thereto.
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 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, 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 CSeries 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 CSeries airplanes will use a fly-by-wire electronic flight
control system (EFCS). This system provides an electronic interface
between the pilot's flight controls and the flight control surfaces for
both normal and failure states; and it generates the actual surface
commands that provide for stability augmentation and control about all
three airplane axes.
The design of the EFCS incorporates the following novel or unusual
design feature: Normal load factor limiting on a full-time basis that
will prevent the flight crew from inadvertently or intentionally
exceeding the positive or negative airplane limit load factor. This
feature is considered novel or unusual because the current regulations
do not provide standards for maneuverability and controllability
evaluations for such systems. Therefore, special conditions are needed
to ensure adequate maneuverability and controllability when using this
design feature.
Discussion
Title 14, Code of Federal Regulations, part 25 does not specify
requirements or policy for demonstrating maneuver control that impose
any handling qualities requirements beyond the design limit structural
loads. Nevertheless, some pilots have become accustomed to the
availability of this excess maneuver capacity in case of extreme
emergency such as upset recoveries or collision avoidance.
As with previous fly-by-wire airplanes, the FAA has no regulatory
or safety reason to prohibit a design for an electronic flight control
system with load factor limiting. It is possible that pilots accustomed
to this feature feel more freedom in commanding full-stick displacement
maneuvers because of the following:
Knowledge that the limit system will protect the
structure,
Low stick force/displacement gradients,
Smooth transition from pilot elevator control to limit
control.
These special conditions will ensure adequate maneuverability and
controllability when using this design feature.
[[Page 32637]]
The normal load factor limit on the CSeries airplanes is unique in
that traditional airplanes with conventional flight control systems
(mechanical linkages) are limited in the pitch axis only by the
elevator surface area and deflection limit. The elevator control power
is normally derived for adequate controllability and maneuverability at
the most critical longitudinal pitching moment. The result is that
traditional airplanes have a significant portion of the flight envelope
wherein maneuverability in excess of limit structural design values is
possible.
These special conditions for the CSeries airplanes supplement the
applicable regulations, including Sec. 25.143, to accommodate the
unique features of the flight envelope limiting systems, and establish
an equivalent level of safety to the existing regulations.
Discussion of Comments
Notice of proposed special conditions No. 25-13-38-SC for the
Bombardier CSeries airplanes was published in the Federal Register on
December 11, 2013 (78 FR 75285). No comments were received, and the
special conditions are adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to the
Models BD-500-1A10 and BD-500-1A11 series airplanes. Should Bombardier
Aerospace apply at a later date for a change to the type certificate to
include another model incorporating the same novel or unusual design
feature, the special conditions would apply to that model as well.
Conclusion
This action affects only certain novel or unusual design features
on two model series 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, 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 Aerospace Models BD-
500-1A10 and BD-500-1A11 series airplanes.
Flight Envelope Protection: Normal Load Factor (g) Limiting
0
1. To meet the intent of adequate maneuverability and controllability
required by Sec. 25.143(a), and in addition to the requirements of
Sec. 25.143(a) and in the absence of other limiting factors, the
following special conditions based on Sec. 25.333(b) apply:
a. The positive limiting load factor must not be less than:
(1) 2.5g for the normal state of the electronic flight control
system with the high lift devices retracted.
(2) 2.0g for the normal state of the electronic flight control
system with the high lift devices extended.
b. The negative limiting load factor must be equal to or more
negative than:
(1) Minus 1.0g for the normal state of the electronic flight
control system with the high lift devices retracted.
(2) 0.0g for the normal state of the electronic flight control
system with high lift devices extended.
c. Maximum reachable positive load factor wings level may be
limited by the characteristics of the electronic flight control system
or flight envelope protections (other than load factor protection)
provided that:
(1) The required values are readily achievable in turns, and
(2) That wings level pitch up is satisfactory.
d. Maximum achievable negative load factor may be limited by the
characteristics of the electronic flight control system or flight
envelope protections (other than load factor protection) provided that:
(1) Pitch down responsiveness is satisfactory, and
(2) From level flight, 0g is readily achievable or alternatively, a
satisfactory trajectory change is readily achievable at operational
speeds. For the FAA to consider a trajectory change as satisfactory,
the applicant should propose and justify a pitch rate that provides
sufficient maneuvering capability in the most critical scenarios.
e. Compliance demonstration with the above requirements may be
performed without ice accretion on the airframe.
These special conditions do not impose an upper bound for the
normal load factor limit, nor do they require that the limit exist. If
the limit is set at a value beyond the structural design limit
maneuvering load factor ``n'' of Sec. Sec. 25.333(b) and 25.337(b) and
(c), there should be a very obvious positive tactile feel built into
the controller so that it serves as a deterrent to inadvertently
exceeding the structural limit.
Issued in Renton, Washington, on April 22, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2014-13241 Filed 6-5-14; 8:45 am]
BILLING CODE 4910-13-P