Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Tire Debris Impacts to Fuel Tanks, 54576-54577 [2014-21786]
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Federal Register / Vol. 79, No. 177 / Friday, September 12, 2014 / Rules and Regulations
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA–2014–0329; Special
Conditions No. 25–560–SC]
Special Conditions: Bombardier
Aerospace, Models BD–500–1A10 and
BD–500–1A11 Series Airplanes; Tire
Debris Impacts to Fuel Tanks
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 the use of carbon
fiber reinforced plastic (CFRP) for most
of the wing fuel tank structure, which,
when impacted by tire debris, may resist
penetration or rupture differently from
aluminum wing skins. 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: October 14, 2014.
FOR FURTHER INFORMATION CONTACT:
Margaret Langsted, FAA, Propulsion
and Mechanical Systems Branch, ANM–
112, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind
Avenue SW., Renton, Washington,
98057–3356; telephone 425–227–2677;
facsimile 425–227–1149.
SUPPLEMENTARY INFORMATION:
mstockstill on DSK4VPTVN1PROD with RULES
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
Model BD–500–1A10 and 144,000
pounds for the Model BD–500–1A11.
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
VerDate Mar<15>2010
17:59 Sep 11, 2014
Jkt 232001
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
requirements of 14 CFR part 36, and 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, in accordance
with § 11.38, and they become part of
the type-certification basis under
§ 21.17(a)(2).
Novel or Unusual Design Features
The CSeries airplanes will incorporate
the following novel or unusual design
features: The use of carbon fiber
reinforced plastic (CFRP) for most of the
wing fuel tank structure. The ability of
aluminum wing skins to resist
penetration or rupture when impacted
by tire debris is understood from
extensive experience, but the ability of
CFRP construction to resist these
hazards has not been established. There
are no existing regulations that
adequately establish a level of safety
with respect to the performance of the
composite materials used in the
construction of wing fuel tanks. It
requires the consideration of fuel tank
penetration, fuel leaks, discrete source
damage tolerance, and the effects of
shock waves generated by tire debris
impact.
Discussion
Accidents have resulted from
uncontrolled fires caused by fuel leaks
following penetration or rupture of the
lower wing by fragments of tires or from
uncontained engine failure. The
Concorde accident in 2000 is the most
notable example. That accident
demonstrated an unanticipated failure
mode in an airplane with an unusual
PO 00000
Frm 00010
Fmt 4700
Sfmt 4700
transport airplane configuration. Impact
to the lower wing surface by tire debris
induced pressure waves within the fuel
tank that resulted in fuel leakage and
fire. Regulatory authorities subsequently
required modifications to the Concorde
to improve impact resistance of the
lower wing or means to retain fuel if the
primary fuel retention means is
damaged.
In another incident, a Boeing Model
747 tire burst during an aborted takeoff
from Honolulu, Hawaii. That tire debris
penetrated a fuel tank access cover,
causing substantial fuel leakage.
Passengers were evacuated down the
emergency chutes into pools of fuel that
fortunately had not ignited.
These accidents highlight deficiencies
in the existing regulations pertaining to
fuel retention following impact of the
fuel tanks by tire fragments. Following
a 1985 Boeing Model 737 accident in
Manchester, England, in which a fuel
tank access panel was penetrated by
engine debris, the FAA amended 14
CFR 25.963 to require fuel tank access
panels that are resistant to both tire and
engine debris (engine debris is
addressed elsewhere). This regulation,
§ 25.963(e), only addressed the fuel tank
access covers since service experience at
the time showed that the lower wing
skin of a conventional, subsonic
airplane provided adequate inherent
capability to resist tire and engine
debris threats. More specifically, that
regulation requires showing by analysis
or tests that the access covers ‘‘. . .
minimize penetration and deformation
by tire fragments, low energy engine
debris, or other likely debris.’’ Advisory
Circular (AC) 25.963–1, Fuel Tank
Access Covers, describes the region of
the wing that is vulnerable to impact
damage from these sources and provides
a method to substantiate that the rule
has been met for tire fragments. No
specific requirements were established
for the contiguous wing areas into
which the access covers are installed,
because of the inherent ability of
conventional aluminum wing skins to
resist penetration by tire debris. AC
25.963–1 specifically notes, ‘‘The access
covers, however, need not be more
impact resistant than the contiguous
tank structure,’’ highlighting the
assumption that the wing structure is
more capable of resisting tire impact
debris than fuel tank access covers.
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. To maintain
the level of safety envisioned by 14 CFR
25.963(e), these special conditions
E:\FR\FM\12SER1.SGM
12SER1
Federal Register / Vol. 79, No. 177 / Friday, September 12, 2014 / Rules and Regulations
establish a standard for resistance to
potential tire debris impacts to the
contiguous wing surfaces and require
consideration of possible secondary
effects of a tire impact, such as the
induced pressure wave that was a factor
in the Concorde accident. It takes into
account that new construction methods
and materials will not necessarily yield
debris resistance that has historically
been shown as adequate. The standard
in these special conditions is based on
the defined tire impact areas and tire
fragment characteristics.
In addition, despite practical design
considerations, some uncommon debris
larger than that defined in paragraph 2
may cause a fuel leak within the defined
area, so paragraph 3 of these special
conditions also takes into consideration
possible leakage paths. Fuel tank
surfaces of typical transport airplanes
have thick aluminum construction in
the tire debris impact areas that is
tolerant to tire debris larger than that
defined in paragraph 2 of these special
conditions. Consideration of leaks
caused by larger tire fragments is
needed to ensure that an adequate level
of safety is provided.
Discussion of Comments
Notice of proposed special conditions
No. 25–14–03–SC for the Bombardier
Aerospace CSeries airplanes was
published in the Federal Register on
June 3, 2014, (79 FR 31886). No
comments were received, and the
special conditions are adopted as
proposed.
Applicability
As discussed above, these special
conditions are applicable to the 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 on the same type
certificate incorporating the same novel
or unusual design feature, these special
conditions would apply to that model as
well.
Conclusion
mstockstill on DSK4VPTVN1PROD with RULES
This action affects only certain novel
or unusual design features on one model
series of airplanes. It is not a rule of
general applicability.
List of Subjects in 14 CFR Part 25
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
VerDate Mar<15>2010
16:18 Sep 11, 2014
Jkt 232001
The Special Conditions
DEPARTMENT OF TRANSPORTATION
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 Aerospace Models
BD–500–1A10 and BD–500–1A11 series
airplanes.
Federal Aviation Administration
Tire Debris Impacts to Fuel Tanks
1. Impacts by tire debris to any fuel
tank or fuel system component located
within 30 degrees to either side of wheel
rotational planes may not result in
penetration or otherwise induce fuel
tank deformation, rupture (for example,
through propagation of pressure waves),
or cracking sufficient to allow a
hazardous fuel leak. A hazardous fuel
leak results if debris impact to a fuel
tank surface causes a—
a. Running leak,
b. Dripping leak, or
c. Leak that, 15 minutes after wiping
dry, results in a wetted airplane surface
exceeding 6 inches in length or
diameter.
The leak must be evaluated under
maximum fuel head pressure.
2. Compliance with paragraph 1 must
be shown by analysis or tests assuming
all of the following:
a. The tire debris fragment size is 1
percent of the tire mass.
b. The tire debris fragment is
propelled at a tangential speed that
could be attained by a tire tread at the
airplane flight manual airplane
rotational speed (VR at maximum gross
weight).
c. The tire debris fragment load is
distributed over an area on the fuel tank
surface equal to 11⁄2 percent of the total
tire tread area.
3. Fuel leaks caused by impact from
tire debris larger than that specified in
paragraph 2, from any portion of a fuel
tank or fuel system component located
within the tire debris impact area
defined in paragraph 1, may not result
in hazardous quantities of fuel entering
any of the following areas of the
airplane:
a. Engine inlet,
b. Auxiliary power unit inlet, or
c. Cabin air inlet.
This must be shown by test or
analysis, or a combination of both, for
each approved engine forward thrust
condition and each approved reverse
thrust condition.
RIN 2120–AA64
■
Issued in Renton, Washington, on
September 3, 2014.
Michael Kaszycki,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
54577
[FR Doc. 2014–21786 Filed 9–11–14; 8:45 am]
BILLING CODE 4910–13–P
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14 CFR Part 39
[Docket No. FAA–2014–0647; Directorate
Identifier 2014–CE–027–AD; Amendment
39–17967; AD 2014–18–03]
Airworthiness Directives; APEX
Aircraft Airplanes
Federal Aviation
Administration (FAA), DOT.
ACTION: Final rule; request for
comments.
AGENCY:
We are adopting a new
airworthiness directive (AD) for APEX
Aircraft Model R 3000/160 airplanes.
This AD results from mandatory
continuing airworthiness information
(MCAI) issued by the aviation authority
of another country to identify and
correct an unsafe condition on an
aviation product. The MCAI describes
the unsafe condition as small pieces of
paint from the engine air intake box
blocking the engine carburetor. We are
issuing this AD to require actions to
address the unsafe condition on these
products.
SUMMARY:
This AD is effective October 17,
2014.
The Director of the Federal Register
approved the incorporation by reference
of a certain publication listed in the AD
as of October 17, 2014.
We must receive comments on this
AD by October 27, 2014.
ADDRESSES: You may send comments by
any of the following methods:
• Federal eRulemaking Portal: Go to
https://www.regulations.gov. Follow the
instructions for submitting comments.
• Fax: (202) 493–2251.
• Mail: U.S. Department of
Transportation, Docket Operations, M–
30, West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue SE.,
Washington, DC 20590.
• Hand Delivery: U.S. Department of
Transportation, Docket Operations, M–
30, West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue SE.,
Washington, DC 20590, between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays.
For service information identified in
this AD, contact CEAPR, Bureau de
´
Navigabilite, 1 route de Troyes, 21121
DAROIS—France, telephone: (33) 380
35 25 22; fax: (33) 380 35 25 25; email:
www.info@ceapr.com; internet: https://
ceapr.com/. You may review copies of
the referenced service information at the
FAA, Small Airplane Directorate, 901
DATES:
E:\FR\FM\12SER1.SGM
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]]>Agencies
[Federal Register Volume 79, Number 177 (Friday, September 12, 2014)]
[Rules and Regulations]
[Pages 54576-54577]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-21786]
[[Page 54576]]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2014-0329; Special Conditions No. 25-560-SC]
Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and
BD-500-1A11 Series Airplanes; Tire Debris Impacts to Fuel Tanks
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
the use of carbon fiber reinforced plastic (CFRP) for most of the wing
fuel tank structure, which, when impacted by tire debris, may resist
penetration or rupture differently from aluminum wing skins. 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: October 14, 2014.
FOR FURTHER INFORMATION CONTACT: Margaret Langsted, FAA, Propulsion and
Mechanical Systems Branch, ANM-112, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington, 98057-3356; telephone 425-227-2677; 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.
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 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, 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 incorporate the following novel or
unusual design features: The use of carbon fiber reinforced plastic
(CFRP) for most of the wing fuel tank structure. The ability of
aluminum wing skins to resist penetration or rupture when impacted by
tire debris is understood from extensive experience, but the ability of
CFRP construction to resist these hazards has not been established.
There are no existing regulations that adequately establish a level of
safety with respect to the performance of the composite materials used
in the construction of wing fuel tanks. It requires the consideration
of fuel tank penetration, fuel leaks, discrete source damage tolerance,
and the effects of shock waves generated by tire debris impact.
Discussion
Accidents have resulted from uncontrolled fires caused by fuel
leaks following penetration or rupture of the lower wing by fragments
of tires or from uncontained engine failure. The Concorde accident in
2000 is the most notable example. That accident demonstrated an
unanticipated failure mode in an airplane with an unusual transport
airplane configuration. Impact to the lower wing surface by tire debris
induced pressure waves within the fuel tank that resulted in fuel
leakage and fire. Regulatory authorities subsequently required
modifications to the Concorde to improve impact resistance of the lower
wing or means to retain fuel if the primary fuel retention means is
damaged.
In another incident, a Boeing Model 747 tire burst during an
aborted takeoff from Honolulu, Hawaii. That tire debris penetrated a
fuel tank access cover, causing substantial fuel leakage. Passengers
were evacuated down the emergency chutes into pools of fuel that
fortunately had not ignited.
These accidents highlight deficiencies in the existing regulations
pertaining to fuel retention following impact of the fuel tanks by tire
fragments. Following a 1985 Boeing Model 737 accident in Manchester,
England, in which a fuel tank access panel was penetrated by engine
debris, the FAA amended 14 CFR 25.963 to require fuel tank access
panels that are resistant to both tire and engine debris (engine debris
is addressed elsewhere). This regulation, Sec. 25.963(e), only
addressed the fuel tank access covers since service experience at the
time showed that the lower wing skin of a conventional, subsonic
airplane provided adequate inherent capability to resist tire and
engine debris threats. More specifically, that regulation requires
showing by analysis or tests that the access covers ``. . . minimize
penetration and deformation by tire fragments, low energy engine
debris, or other likely debris.'' Advisory Circular (AC) 25.963-1, Fuel
Tank Access Covers, describes the region of the wing that is vulnerable
to impact damage from these sources and provides a method to
substantiate that the rule has been met for tire fragments. No specific
requirements were established for the contiguous wing areas into which
the access covers are installed, because of the inherent ability of
conventional aluminum wing skins to resist penetration by tire debris.
AC 25.963-1 specifically notes, ``The access covers, however, need not
be more impact resistant than the contiguous tank structure,''
highlighting the assumption that the wing structure is more capable of
resisting tire impact debris than fuel tank access covers.
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. To maintain the level of safety envisioned by 14 CFR
25.963(e), these special conditions
[[Page 54577]]
establish a standard for resistance to potential tire debris impacts to
the contiguous wing surfaces and require consideration of possible
secondary effects of a tire impact, such as the induced pressure wave
that was a factor in the Concorde accident. It takes into account that
new construction methods and materials will not necessarily yield
debris resistance that has historically been shown as adequate. The
standard in these special conditions is based on the defined tire
impact areas and tire fragment characteristics.
In addition, despite practical design considerations, some uncommon
debris larger than that defined in paragraph 2 may cause a fuel leak
within the defined area, so paragraph 3 of these special conditions
also takes into consideration possible leakage paths. Fuel tank
surfaces of typical transport airplanes have thick aluminum
construction in the tire debris impact areas that is tolerant to tire
debris larger than that defined in paragraph 2 of these special
conditions. Consideration of leaks caused by larger tire fragments is
needed to ensure that an adequate level of safety is provided.
Discussion of Comments
Notice of proposed special conditions No. 25-14-03-SC for the
Bombardier Aerospace CSeries airplanes was published in the Federal
Register on June 3, 2014, (79 FR 31886). No comments were received, and
the special conditions are adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to the
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 on the same type certificate 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 one 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
0
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 Aerospace Models BD-500-
1A10 and BD-500-1A11 series airplanes.
Tire Debris Impacts to Fuel Tanks
1. Impacts by tire debris to any fuel tank or fuel system component
located within 30 degrees to either side of wheel rotational planes may
not result in penetration or otherwise induce fuel tank deformation,
rupture (for example, through propagation of pressure waves), or
cracking sufficient to allow a hazardous fuel leak. A hazardous fuel
leak results if debris impact to a fuel tank surface causes a--
a. Running leak,
b. Dripping leak, or
c. Leak that, 15 minutes after wiping dry, results in a wetted
airplane surface exceeding 6 inches in length or diameter.
The leak must be evaluated under maximum fuel head pressure.
2. Compliance with paragraph 1 must be shown by analysis or tests
assuming all of the following:
a. The tire debris fragment size is 1 percent of the tire mass.
b. The tire debris fragment is propelled at a tangential speed that
could be attained by a tire tread at the airplane flight manual
airplane rotational speed (VR at maximum gross weight).
c. The tire debris fragment load is distributed over an area on the
fuel tank surface equal to 1\1/2\ percent of the total tire tread area.
3. Fuel leaks caused by impact from tire debris larger than that
specified in paragraph 2, from any portion of a fuel tank or fuel
system component located within the tire debris impact area defined in
paragraph 1, may not result in hazardous quantities of fuel entering
any of the following areas of the airplane:
a. Engine inlet,
b. Auxiliary power unit inlet, or
c. Cabin air inlet.
This must be shown by test or analysis, or a combination of both,
for each approved engine forward thrust condition and each approved
reverse thrust condition.
Issued in Renton, Washington, on September 3, 2014.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2014-21786 Filed 9-11-14; 8:45 am]
BILLING CODE 4910-13-P
