Special Conditions: Airbus A350-900 Airplane; Crashworthiness, Emergency Landing Conditions, 43237-43239 [2014-17574]
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Federal Register / Vol. 79, No. 143 / Friday, July 25, 2014 / Rules and Regulations
Discussion
Section 25.701(a) requires that, unless
the airplane has safe-flight
characteristics with the flaps or slats
retracted on one side and extended on
the other, flap and slat surfaces must be
synchronized by either a mechanical
interconnection or any equivalent
means that has the same integrity.
Synchronization is interpreted to mean
that flap movement is symmetrical
throughout the full range of flap motion.
Because the lateral-trim function
intentionally creates asymmetric flap
motions, the flap-system installation of
the Model A350–900 airplane does not
meet the requirement of § 25.701(a) and
(d).
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. 25–13–22–SC for Airbus Model
A350–900 airplanes was published in
the Federal Register on January 8, 2014
(79 FR 1339). No comments were
received, and the special conditions are
adopted as proposed.
Applicability
As discussed above, these special
conditions apply to Airbus Model
A350–900 airplanes. Should Airbus
apply later 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.
Lateral-Trim Function Through
Differential Flap Setting
Current airworthiness standards,
specifically § 25.701, do not contain
adequate safety standards for this
airplane design. In lieu of the
requirements of § 25.701(a) and (d) for
the lateral-trim function, the following
special condition are issued:
1. Airbus must demonstrate that an
unsafe condition is not created by using
the flaps asymmetrically.
2. The degree of acceptable
asymmetry must be defined and
justified for all flight phases with
respect to:
a. Section 25.701(b) and (c), with the
worst-case asymmetric flap
configurations, and
b. Providing equivalent protection
against excess asymmetry in the same
manner as § 25.701 provides to systems
that are synchronized, or use another
equivalent means to prevent asymmetry.
3. This lateral-trim function is a flightcontrol system and therefore must be
shown to comply with both general
system requirements as well as general
flight-control requirements. Therefore,
the function must be demonstrated not
to have significant latent failures, where
practicable.
Issued in Renton, Washington, on July 9,
2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 2014–17578 Filed 7–24–14; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
Conclusion
14 CFR Part 25
This action affects only certain novel
or unusual design features on the Airbus
Model A350–900 airplanes. It is not a
rule of general applicability.
[Docket No. FAA–2013–0892; Special
Conditions No. 25–537–SC]
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions.
AGENCY:
The authority citation for these
special conditions is as follows:
rmajette on DSK2TPTVN1PROD 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 typecertification basis for Airbus Model
A350–900 airplanes:
15:26 Jul 24, 2014
Jkt 232001
These special conditions are
issued for Airbus Model A350–900
airplanes. These airplanes have a novel
or unusual design feature associated
with crashworthiness of carbon-fiberreinforced plastic used in the
construction of the fuselage. The
applicable airworthiness regulations do
not contain adequate or appropriate
safety standards for this design feature.
These special conditions contain the
SUMMARY:
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
VerDate Mar<15>2010
Special Conditions: Airbus A350–900
Airplane; Crashworthiness, Emergency
Landing Conditions
PO 00000
Frm 00007
Fmt 4700
Sfmt 4700
43237
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: August 25, 2014.
FOR FURTHER INFORMATION CONTACT:
Todd Martin, FAA, Airframe/Cabin
Safety, ANM–115, Transport Airplane
Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW.,
Renton, Washington 98057–3356;
telephone (425) 227–1178; facsimile
(425) 227–1320.
SUPPLEMENTARY INFORMATION:
Background
On August 25, 2008, Airbus applied
for a type certificate for their new Model
A350–900 airplane. Later, Airbus
requested, and the FAA approved, an
extension to the application for FAA
type certification to November 15, 2009.
The Model A350–900 airplane has a
conventional layout with twin wingmounted Rolls-Royce Trent XWB
engines. It features a twin-aisle, 9abreast, economy-class layout, and
accommodates side-by-side placement
of LD–3 containers in the cargo
compartment. The basic Model A350–
900 airplane configuration
accommodates 315 passengers in a
standard two-class arrangement. The
design cruise speed is Mach 0.85 with
a maximum take-off weight of 602,000
lbs.
Changes in the structural behavior of
the Airbus Model A350–900 airplane,
compared to currently certificated
designs, could degrade the survivability
of the Model A350–900 airplane
occupants in crash conditions that are
within the limits of survivability for
other designs.
The airworthiness regulations specify
no aircraft-level survivable crash
condition, and metallic aircraft have not
been designed specifically against
survivable impact conditions. However,
the structural behavior of previously
certificated aircraft in a survivable crash
event, and the associated limits, are
considered generally acceptable. It is
therefore reasonable to expect that a
design using new materials, such as the
Model A350–900 airplanes use, should
be assessed to ensure that the material
meets the currently accepted level of
safety.
The FAA and industry have collected
a significant amount of experimental
data, as well as data from crashes of
transport-category airplanes, that show a
high occupant-survival rate at verticaldescent velocities up to 30 ft/sec. Based
on this information, the FAA finds it
appropriate and necessary for an
E:\FR\FM\25JYR1.SGM
25JYR1
43238
Federal Register / Vol. 79, No. 143 / Friday, July 25, 2014 / Rules and Regulations
assessment of the Model A350–900
airplane to span a range of airplane
vertical-descent speeds up to 30 ft/sec.
rmajette on DSK2TPTVN1PROD with RULES
Type Certification Basis
Under Title 14, Code of Federal
Regulations (14 CFR) 21.17, Airbus must
show that the Model A350–900 airplane
meets the applicable provisions of 14
CFR 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 A350–900 airplane
because of a novel or unusual design
feature, special conditions are
prescribed under § 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 Model A350–900
airplane must comply with the fuel-vent
and exhaust-emission requirements of
14 CFR part 34 and the noisecertification requirements of 14 CFR
part 36. 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, under § 11.38,
and they become part of the typecertification basis under § 21.17(a)(2).
Novel or Unusual Design Features
The Airbus Model A350–900 airplane
incorporates the following novel or
unusual design feature: A fuselage
fabricated with a combination of carbonfiber-reinforced plastic (CFRP) and
metallic structure. This is a novel and
unusual design feature for a large
transport airplane. Structure fabricated
from CFRP may behave differently than
metallic structure in crash conditions
because of differences in material
ductility, stiffness, failure modes, and
energy-absorption characteristics.
Therefore, the impact-response
characteristics of the Model A350–900
airplane must be evaluated to ensure
that its survivable crashworthiness
characteristics provide at least the same
level of safety as those of a similarly
sized airplane constructed from
traditional metallic materials.
No existing regulations adequately
address this potential difference in
impact-response characteristics for what
VerDate Mar<15>2010
15:26 Jul 24, 2014
Jkt 232001
are considered survivable crash
conditions. The special conditions are
necessary to ensure a level of safety
equivalent to that provided by 14 CFR
part 25.
certificate to include another model
incorporating the same novel or unusual
design feature, the special conditions
would apply to that model as well.
Discussion
Factors in crash survivability are:
• Retention of items of mass,
• maintenance of occupant
emergency egress paths,
• maintenance of acceptable
acceleration and loads experienced by
the occupants, and
• maintenance of a survivable
volume.
To provide the same level of safety as
exists with conventional airplane
construction, Airbus should show that
the Model A350–900 airplane has
sufficient crashworthiness capabilities
under foreseeable survivable impact
events. To show this, Airbus should
evaluate the impact-response
characteristics of the Model A350–900
airplane to ensure that its
crashworthiness characteristics are not
significantly different from those of a
similarly sized airplane built from
traditional metallic materials.
In their evaluation of the Model
A350–900 airplane response to an
impact event, Airbus should
demonstrate that the structural behavior
is similar to that expected from a
metallic airframe of a size similar to the
Model A350–900, or incorporate
mitigating design features that provide a
similar level of safety.
Airbus should demonstrate, either
through analysis using validated
analytical tools or by direct-test
evidence, that the crash dynamics of the
Model A350–900 fuselage structure
provides a level of occupant protection
consistent with previously certificated
large transport-category airplanes.
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.
This action affects only certain novel
or unusual design features on the Airbus
Model A350–900 airplane. It is not a
rule of general applicability.
Discussion of Comments
Notice of Proposed Special
Conditions No. 25–13–21–SC for the
Airbus Model A350–900 airplane was
published in the Federal Register on
January 8, 2014 (79 FR 1337). No
comments were received, and the
special conditions are adopted as
proposed.
Applicability
As discussed above, these special
conditions apply to Airbus Model
A350–900 airplanes. Should Airbus
apply later for a change to the type
PO 00000
Frm 00008
Fmt 4700
Sfmt 4700
Conclusion
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 typecertification basis for Airbus Model
A350–900 airplanes.
The Airbus Model A350–900 airplane
must provide an equivalent level of
occupant safety and survivability, to
that provided by previously certificated
wide-body transport-category airplanes
of similar size, under foreseeable
survivable impact events for the
following four criteria. To demonstrate
an equivalent level of occupant safety
and survivability, the applicant must
demonstrate that Model A350–900
airplanes meet the following criteria for
a range of airplane vertical-descent
velocities up to 30 ft/sec.
1. Retention of Items of Mass
The occupants, i.e., passengers, flight
attendants, and flightcrew, must be
protected during the impact event from
release of seats, overhead bins, and
other items of mass, due to the impact
loads and resultant structural
deformation of the supporting airframe
and floor structures. The applicant must
show that loads, due to the impact event
and resultant structural deformation of
the supporting airframe and floor
structure at the interface of the airplane
structure to seats, overhead bins, and
other items of mass, are comparable to
those of previously certificated widebody transports of similar size for the
range of descent velocities stated above.
The attachments of these items need not
be designed for static emergencylanding loads in excess of those defined
in § 25.561 if impact-response
characteristics of the Airbus Model
A350–900 airplane yields load factors at
the attach points that are comparable to
those for a previously certificated widebody transport-category airplane.
E:\FR\FM\25JYR1.SGM
25JYR1
Federal Register / Vol. 79, No. 143 / Friday, July 25, 2014 / Rules and Regulations
2. Maintenance of Acceptable
Acceleration and Loads Experienced by
the Occupants
DEPARTMENT OF TRANSPORTATION
The applicant must show that the
impact response characteristics of the
Airbus Model A350–900 airplane,
specifically the vertical acceleration
levels experienced at the seat/floor
interface, and loads experienced by the
occupants during the impact events, are
consistent with those found in
§ 25.562(b), or with levels expected for
a previously certificated wide-body
transport-category airplane for the
conditions stated above.
14 CFR Part 25
3. Maintenance of a Survivable Volume
For the conditions stated above, the
applicant must show that all areas of the
airplane occupied for takeoff and
landing provide a survivable volume
comparable to that of previously
certificated wide-body transportcategory airplanes of similar size during
and after the impact event. This means
that structural deformation will not
result in infringement of the occupants’
normal living space, so that passenger
survivability will not be significantly
affected.
4. Maintenance of Occupant Emergency
Egress Paths
The evacuation of occupants must be
comparable to that from a previously
certificated wide-body transportcategory airplane of similar size. To
show this, the applicant must show that
the suitability of the egress paths, as
determined following the verticalimpact events, is comparable to the
suitability of the egress paths of a
comparable, certificated, wide-body
transport-category airplane, as
determined following the same verticalimpact events.
Issued in Renton, Washington, on July 9,
2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 2014–17574 Filed 7–24–14; 8:45 am]
rmajette on DSK2TPTVN1PROD with RULES
BILLING CODE 4910–13–P
VerDate Mar<15>2010
15:26 Jul 24, 2014
Jkt 232001
Federal Aviation Administration
[Docket No. FAA–2013–0910; Special
Conditions No. 25–534–SC]
Special Conditions: Airbus Model
A350–900 Airplanes; Isolation or
Protection of the Aircraft Electronic
System Security From Unauthorized
Internal Access
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions.
AGENCY:
These special conditions are
issued for Airbus Model A350–900
airplanes. These airplanes will have a
novel or unusual design feature
associated with airplane electronic
system security protection or isolation
from unauthorized internal access. 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: August 25, 2014.
FOR FURTHER INFORMATION CONTACT:
Varun Khanna, FAA, Airplane and
Flightcrew Interface Branch, ANM–111,
Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington, 98057–3356;
telephone (425) 227–1298; facsimile
(425) 227–1320.
SUPPLEMENTARY INFORMATION:
SUMMARY:
Background
On August 25, 2008, Airbus applied
for a type certificate for their new Model
A350–900 airplane. Later, Airbus
requested, and the FAA approved, an
extension to the application for FAA
type certification to November 15, 2009.
The Model A350–900 airplane has a
conventional layout with twin wingmounted Rolls-Royce Trent XWB
engines. It features a twin-aisle, 9abreast, economy-class layout, and
accommodates side-by-side placement
of LD–3 containers in the cargo
compartment. The basic Model A350–
900 airplane configuration
accommodates 315 passengers in a
standard two-class arrangement. The
design cruise speed is Mach 0.85 with
a maximum take-off weight of 602,000
lbs.
Contemporary transport-category
airplanes have both safety-related and
PO 00000
Frm 00009
Fmt 4700
Sfmt 4700
43239
non-safety-related electronic system
networks for many operational
functions. However, electronic system
network security considerations and
functions have played a relatively minor
role in the certification of such systems
because of the isolation, protection
mechanisms, and limited connectivity
between the different networks.
Type Certification Basis
Under Title 14, Code of Federal
Regulations (14 CFR) 21.17, Airbus must
show that the Model A350–900 airplane
meets the applicable provisions of 14
CFR 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 A350–900 airplane
because of a novel or unusual design
feature, special conditions are
prescribed under § 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, the special conditions
would also apply to the other model
under § 21.101.
In addition to the applicable
airworthiness regulations and special
conditions, the Model A350–900
airplane must comply with the fuel-vent
and exhaust-emission requirements of
14 CFR part 34, and the noisecertification requirements of 14 CFR
part 36. The FAA must issue a finding
of regulatory adequacy under section
611 of Public Law 92–574, the ‘‘Noise
Control Act of 1972.’’
The FAA issues special conditions, as
defined in 14 CFR 11.19, under § 11.38,
and they become part of the typecertification basis under § 21.17(a)(2).
Novel or Unusual Design Features
The Airbus Model A350–900 airplane
will incorporate the following novel or
unusual design feature: An electronics
network system architecture that is
novel or unusual for commercial
transport airplanes, and that introduces
potential security risks and
vulnerabilities not addressed in current
regulations and airplane-level or
system-level safety assessment methods.
Discussion
The Airbus Model A350–900 airplane
architecture is novel or unusual for
commercial transport airplanes because
it allows connection to previously
isolated data networks connected to
systems that perform functions required
E:\FR\FM\25JYR1.SGM
25JYR1
]]>Agencies
[Federal Register Volume 79, Number 143 (Friday, July 25, 2014)]
[Rules and Regulations]
[Pages 43237-43239]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-17574]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2013-0892; Special Conditions No. 25-537-SC]
Special Conditions: Airbus A350-900 Airplane; Crashworthiness,
Emergency Landing Conditions
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for Airbus Model A350-900
airplanes. These airplanes have a novel or unusual design feature
associated with crashworthiness of carbon-fiber-reinforced plastic used
in the construction of the fuselage. 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: August 25, 2014.
FOR FURTHER INFORMATION CONTACT: Todd Martin, FAA, Airframe/Cabin
Safety, ANM-115, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone
(425) 227-1178; facsimile (425) 227-1320.
SUPPLEMENTARY INFORMATION:
Background
On August 25, 2008, Airbus applied for a type certificate for their
new Model A350-900 airplane. Later, Airbus requested, and the FAA
approved, an extension to the application for FAA type certification to
November 15, 2009. The Model A350-900 airplane has a conventional
layout with twin wing-mounted Rolls-Royce Trent XWB engines. It
features a twin-aisle, 9-abreast, economy-class layout, and
accommodates side-by-side placement of LD-3 containers in the cargo
compartment. The basic Model A350-900 airplane configuration
accommodates 315 passengers in a standard two-class arrangement. The
design cruise speed is Mach 0.85 with a maximum take-off weight of
602,000 lbs.
Changes in the structural behavior of the Airbus Model A350-900
airplane, compared to currently certificated designs, could degrade the
survivability of the Model A350-900 airplane occupants in crash
conditions that are within the limits of survivability for other
designs.
The airworthiness regulations specify no aircraft-level survivable
crash condition, and metallic aircraft have not been designed
specifically against survivable impact conditions. However, the
structural behavior of previously certificated aircraft in a survivable
crash event, and the associated limits, are considered generally
acceptable. It is therefore reasonable to expect that a design using
new materials, such as the Model A350-900 airplanes use, should be
assessed to ensure that the material meets the currently accepted level
of safety.
The FAA and industry have collected a significant amount of
experimental data, as well as data from crashes of transport-category
airplanes, that show a high occupant-survival rate at vertical-descent
velocities up to 30 ft/sec. Based on this information, the FAA finds it
appropriate and necessary for an
[[Page 43238]]
assessment of the Model A350-900 airplane to span a range of airplane
vertical-descent speeds up to 30 ft/sec.
Type Certification Basis
Under Title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus
must show that the Model A350-900 airplane meets the applicable
provisions of 14 CFR 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 A350-900 airplane because of
a novel or unusual design feature, special conditions are prescribed
under 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 A350-900 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,
under Sec. 11.38, and they become part of the type-certification basis
under Sec. 21.17(a)(2).
Novel or Unusual Design Features
The Airbus Model A350-900 airplane incorporates the following novel
or unusual design feature: A fuselage fabricated with a combination of
carbon-fiber-reinforced plastic (CFRP) and metallic structure. This is
a novel and unusual design feature for a large transport airplane.
Structure fabricated from CFRP may behave differently than metallic
structure in crash conditions because of differences in material
ductility, stiffness, failure modes, and energy-absorption
characteristics. Therefore, the impact-response characteristics of the
Model A350-900 airplane must be evaluated to ensure that its survivable
crashworthiness characteristics provide at least the same level of
safety as those of a similarly sized airplane constructed from
traditional metallic materials.
No existing regulations adequately address this potential
difference in impact-response characteristics for what are considered
survivable crash conditions. The special conditions are necessary to
ensure a level of safety equivalent to that provided by 14 CFR part 25.
Discussion
Factors in crash survivability are:
Retention of items of mass,
maintenance of occupant emergency egress paths,
maintenance of acceptable acceleration and loads
experienced by the occupants, and
maintenance of a survivable volume.
To provide the same level of safety as exists with conventional
airplane construction, Airbus should show that the Model A350-900
airplane has sufficient crashworthiness capabilities under foreseeable
survivable impact events. To show this, Airbus should evaluate the
impact-response characteristics of the Model A350-900 airplane to
ensure that its crashworthiness characteristics are not significantly
different from those of a similarly sized airplane built from
traditional metallic materials.
In their evaluation of the Model A350-900 airplane response to an
impact event, Airbus should demonstrate that the structural behavior is
similar to that expected from a metallic airframe of a size similar to
the Model A350-900, or incorporate mitigating design features that
provide a similar level of safety.
Airbus should demonstrate, either through analysis using validated
analytical tools or by direct-test evidence, that the crash dynamics of
the Model A350-900 fuselage structure provides a level of occupant
protection consistent with previously certificated large transport-
category airplanes.
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. 25-13-21-SC for the
Airbus Model A350-900 airplane was published in the Federal Register on
January 8, 2014 (79 FR 1337). No comments were received, and the
special conditions are adopted as proposed.
Applicability
As discussed above, these special conditions apply to Airbus Model
A350-900 airplanes. Should Airbus apply later 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 the Airbus Model A350-900 airplane. 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 Airbus Model A350-900 airplanes.
The Airbus Model A350-900 airplane must provide an equivalent level
of occupant safety and survivability, to that provided by previously
certificated wide-body transport-category airplanes of similar size,
under foreseeable survivable impact events for the following four
criteria. To demonstrate an equivalent level of occupant safety and
survivability, the applicant must demonstrate that Model A350-900
airplanes meet the following criteria for a range of airplane vertical-
descent velocities up to 30 ft/sec.
1. Retention of Items of Mass
The occupants, i.e., passengers, flight attendants, and flightcrew,
must be protected during the impact event from release of seats,
overhead bins, and other items of mass, due to the impact loads and
resultant structural deformation of the supporting airframe and floor
structures. The applicant must show that loads, due to the impact event
and resultant structural deformation of the supporting airframe and
floor structure at the interface of the airplane structure to seats,
overhead bins, and other items of mass, are comparable to those of
previously certificated wide-body transports of similar size for the
range of descent velocities stated above. The attachments of these
items need not be designed for static emergency-landing loads in excess
of those defined in Sec. 25.561 if impact-response characteristics of
the Airbus Model A350-900 airplane yields load factors at the attach
points that are comparable to those for a previously certificated wide-
body transport-category airplane.
[[Page 43239]]
2. Maintenance of Acceptable Acceleration and Loads Experienced by the
Occupants
The applicant must show that the impact response characteristics of
the Airbus Model A350-900 airplane, specifically the vertical
acceleration levels experienced at the seat/floor interface, and loads
experienced by the occupants during the impact events, are consistent
with those found in Sec. 25.562(b), or with levels expected for a
previously certificated wide-body transport-category airplane for the
conditions stated above.
3. Maintenance of a Survivable Volume
For the conditions stated above, the applicant must show that all
areas of the airplane occupied for takeoff and landing provide a
survivable volume comparable to that of previously certificated wide-
body transport-category airplanes of similar size during and after the
impact event. This means that structural deformation will not result in
infringement of the occupants' normal living space, so that passenger
survivability will not be significantly affected.
4. Maintenance of Occupant Emergency Egress Paths
The evacuation of occupants must be comparable to that from a
previously certificated wide-body transport-category airplane of
similar size. To show this, the applicant must show that the
suitability of the egress paths, as determined following the vertical-
impact events, is comparable to the suitability of the egress paths of
a comparable, certificated, wide-body transport-category airplane, as
determined following the same vertical-impact events.
Issued in Renton, Washington, on July 9, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2014-17574 Filed 7-24-14; 8:45 am]
BILLING CODE 4910-13-P
