Special Conditions: Bombardier Inc., Models BD-500-1A10 and BD-500-1A11 series airplanes; Fuselage In-Flight Fire Safety and Flammability Resistance, 65231-65233 [2013-25663]
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Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Proposed Rules
After the expiration of the period for
submitting written statements, the
Department will consider all comments
and additional information that is
obtained from interested parties or
through further analyses, and it will
prepare a final determination. If DOE
determines that miscellaneous
residential refrigeration products qualify
as covered products, DOE will consider
initiating rulemakings to develop test
procedures and energy conservation
standards for miscellaneous residential
refrigeration products. Members of the
public will be given an opportunity to
submit written and oral comments on
any proposed test procedure and
standards.
List of Subjects in 10 CFR part 430
Administrative practice and
procedure, Confidential business
information, Energy conservation,
Reporting and recordkeeping
requirements.
Issued in Washington, DC, on September
30, 2013.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy
Efficiency and Renewable Energy.
[FR Doc. 2013–25943 Filed 10–30–13; 8:45 am]
BILLING CODE 6450–01–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA–2013–0819; Notice No. 25–
13–06–SC]
Special Conditions: Bombardier Inc.,
Models BD–500–1A10 and BD–500–
1A11 series airplanes; Fuselage InFlight Fire Safety and Flammability
Resistance
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed special
conditions.
AGENCY:
This action proposes special
conditions for the Bombardier Inc.
Model BD–500–1A10 and BD–500–
1A11 series airplanes. These airplanes
will have a novel or unusual design
feature associated with the materials
used to fabricate the fuselage, which
may affect fire propagation during an inflight fire. 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
tkelley on DSK3SPTVN1PROD with PROPOSALS
SUMMARY:
VerDate Mar<15>2010
16:47 Oct 30, 2013
Jkt 232001
of safety equivalent to that established
by the existing airworthiness standards.
DATES: Send your comments on or
before December 16, 2013.
ADDRESSES: Send comments identified
by docket number [FAA–2013–0819]
using any of the following methods:
• Federal eRegulations Portal: Go to
https://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 8
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 https://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 https://DocketsInfo.dot.gov/
.
Docket: Background documents or
comments received may be read at
https://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:
Alan Sinclair, FAA, Airframe and Cabin
Safety Branch, ANM–115, Transport
Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington, 98057–3356;
telephone 425–227–2195; facsimile
425–227–1232.
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
PO 00000
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Fmt 4702
Sfmt 4702
65231
specific portion of the special
conditions, explain the reason for any
recommended change, and include
supporting data.
We will consider all comments we
receive on or before the closing date for
comments. We may change these special
conditions based on the comments we
receive.
Background
On December 10, 2009, Bombardier
Inc. applied for a type certificate for
their new Model BD–500–1A10 and
BD–500–1A11 series airplanes. The
Model BD–500–1A10 and BD–500–
1A11 series airplanes are swept-wing
monoplanes with pressurized cabins,
and they share an identical supplier
base and significant common design
elements. The fuselages are aluminum
alloy material, blended double-bubble
design, sized for nominal 5 abreast
seating. Each airplane’s powerplant
includes two under-wing Pratt and
Whitney PW1524G ultra-high bypass,
geared turbofan engines. Flight controls
are fly-by-wire flight with two passive/
uncoupled side sticks. Avionics include
five landscape primary cockpit displays.
The dimension of the airplanes
encompasses a wingspan of 115 feet; a
height of 37.75 feet; and a length of
114.75 feet for the Model BD–500–1A10
and 127 feet for the Model BD–500–
1A11. 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. Maximum takeoff thrust is
21,000 pounds for the Model BD–500–
1A10 and 23,300 pounds for the Model
BD–500–1A11. The range is 3,394 miles
(5,463 kilometers) for both model
airplanes. The maximum operating
altitude is 41,000 feet for both model
airplanes.
The Bombardier BD–500–1A10 and
BD–500–1A11 series airplanes will be
fabricated using aluminum-lithium
materials. The performance of airplanes
consisting of a conventional aluminum
fuselage in an inaccessible in-flight fire
scenario is understood based on service
history and extensive intermediate and
large-scale fire testing. The fuselage
itself does not contribute to in-flight fire
propagation. This may not be the case
for an all-aluminum-lithium fuselage.
Experience has shown that eliminating
the fire propagation of the interior
materials and insulation materials tends
to increase survivability since other
aspects of in-flight fire safety (e.g., toxic
gas emission and smoke obscuration)
are typically by-products of the
propagating fire. The Bombardier BD–
E:\FR\FM\31OCP1.SGM
31OCP1
65232
Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Proposed Rules
500–1A10 and BD–500–1A11 series
airplanes must provide protection
against an in-flight fire propagating
along the surface of the fuselage.
Type Certification Basis
Under the provisions of Title 14, Code
of Federal Regulations (14 CFR) 21.17,
Bombardier Inc. must show that the
Model BD–500–1A10 and BD–500–
1A11 series 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 Model BD–500–1A10 and BD–
500–1A11 series 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 Model BD–500–1A10
and BD–500–1A11 series 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 § 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).
tkelley on DSK3SPTVN1PROD with PROPOSALS
Novel or Unusual Design Features
The Model BD–500–1A10 and BD–
500–1A11 series airplanes will
incorporate the following novel or
unusual design features: The fuselage
will be fabricated using aluminumlithium materials instead of
conventional aluminum. This new type
of material must provide protection
against an in-flight fire propagating
along the surface of the fuselage.
Discussion
The Bombardier BD–500–1A10 and
BD–500–1A11 series airplanes will be
fabricated using aluminum-lithium
materials. The performance of airplanes
consisting of a conventional aluminum
fuselage in an inaccessible in-flight fire
scenario is understood based on service
VerDate Mar<15>2010
16:47 Oct 30, 2013
Jkt 232001
history and extensive intermediate and
large-scale fire testing. Experience has
shown that eliminating the fire
propagation of the interior materials and
insulation materials tends to increase
survivability since other aspects of inflight fire safety (e.g., toxic gas emission
and smoke obscuration) are typically byproducts of the propagating fire. The
fuselage itself does not contribute to inflight fire propagation. This may not be
the case for an all-aluminum-lithium
fuselage.
In the past, fatal in-flight fires have
originated in inaccessible areas of the
airplane where thermal/acoustic
insulation located adjacent to the
aluminum airplane skin has been the
path for flame propagation and fire
growth. Concern over the fire
performance of thermal/acoustic
insulation was initially raised by five
incidents in the 1990’s, which revealed
unexpected flame spread along the
insulation film that covered the
thermal/acoustic insulation. In all cases,
the ignition source was relatively
modest and, in most cases, was
electrical in origin (e.g., electrical short
circuit, arcing caused by chafed wiring,
ruptured ballast case).
In 1996, the FAA Technical Center
began a program to develop new fire test
criteria for insulation films directly
relating to in-flight fire resistance. The
current test standard at that time was
evaluated as well as another small-scale
test method that has been used by
airplane manufacturers to evaluate
flame propagation on thermal/acoustic
insulation materials.
An inter-laboratory comparison of
these methods revealed a number of
deficiencies. A new test method
subjecting a material to a pilot flame
while the material is heated by a radiant
panel was developed. The new radiant
panel test method and criteria were
specifically established to improve the
evaluation of the in-flight fire ignition/
flame propagation of thermal/acoustic
insulation materials based on real-world
fire scenarios. While these tests were
developed for thermal/acoustic
insulation materials, this same type of
test methodology can be used to assess
the flammability characteristics of the
proposed aluminum-lithium material
for the fuselage.
The FAA reviewed the test method
proposed by Bombardier Inc. and
determined that a larger flame and test
article would be necessary to make a
determination of the potential
flammability of the aluminum-lithium
material. It would also be more
representative of a real-life fire scenario.
The FAA recently conducted
additional testing in our Components
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Fmt 4702
Sfmt 4702
Fire Test facility and determined that
another way to assess the survivability
within the cabin of the Model BD–500–
1A10 and BD–500–1A11 series is to use
the cargo liner flammability test (part III
of appendix F to part 25, Test Method
to Determine Flame Penetration
Resistance of Cargo Compartment
Liners). However, the problem with
using this particular test is that when
the aluminum panels melt, molten globs
of aluminum fall directly into the
burner, which adversely affects the
flame. So the FAA decided that a
similar test for the measurement of
insulation burnthrough resistance could
be used (part VII of appendix F to part
25, Test Method to Determine the
Burnthrough Resistance of Thermal/
Acoustic Insulation Materials).
Although this test method uses the same
burner as the cargo liner test, it uses a
slightly larger flame. In addition, the
burner is not vertical, so there was no
problem with molten material falling
into it, requiring disassembly of the
burner. The only slight change was the
size of the sample and the sample
holder. These were modified slightly to
accommodate the samples that we
received.
The recent FAA tests that were
conducted in our Components Fire Test
facility used a 6 gallon/hour oil burner,
the same apparatus used to determine
burnthrough resistance of thermal/
acoustic insulation (part VII of appendix
F to part 25). The test used 16 by 24
inch Al-Li panels that were installed
into a sheet steel subframe, which
measured 18 by 32 inches (outside
dimensions). The subframe had an
opening cut into it, which measured
14.5 by 22.5 inches; this allowed the test
panels to be mounted onto the subframe
using .250–20 UNC threaded bolts.
The FAA proposes that Bombardier
use the test method contained in part
VII of appendix F to part 25, Test
Method to Determine the Burnthrough
Resistance of Thermal/Acoustic
Insulation Materials, with the slight
changes to the sample size and sample
holder as an alternate test method to
show compliance with applicable
requirements. Bombardier Inc. is
responsible for finding a suitable testing
facility in which to conduct the testing.
Applicability
As discussed above, these special
conditions are applicable to the Model
BD–500–1A10 and BD–500–1A11
airplanes. Should Bombardier Inc. 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.
E:\FR\FM\31OCP1.SGM
31OCP1
Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Proposed Rules
Conclusion
This action affects only certain novel
or unusual design features on two
models of airplanes. It is not a rule of
general applicability.
Issued in Renton, Washington, on
September 12, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. 2013–25663 Filed 10–30–13; 8:45 am]
List of Subjects in 14 CFR Part 25
BILLING CODE 4910–13–P
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
DEPARTMENT OF TRANSPORTATION
The authority citation for these
special conditions is as follows:
Federal Aviation Administration
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
14 CFR Part 25
tkelley on DSK3SPTVN1PROD with PROPOSALS
The Proposed Special Conditions
Accordingly, the Federal Aviation
Administration (FAA) proposes the
following special conditions as part of
the type certification basis for
Bombardier Inc. Model BD–500–1A10
and BD–500–1A11 series airplanes.
1. Fuselage In-Flight Fire Safety and
Flammability Resistance. Bombardier
must demonstrate that the fuselage
would not materially contribute to the
propagation of an in-flight fire or
introduce any additional in-flight fire
risk.
2. To demonstrate compliance, the
test set-up and methodology must be
commensurate with 14 CFR part 25,
appendix F, part VII, except the size of
the test samples, modifications to the
sample holder, and the test
methodology would be varied as
described below.
3. In demonstrating that the
aluminum-lithium material used to
fabricate the fuselage has equal or better
flammability resistance characteristics
than the aluminum alloy sheet typically
used as skin material on similar
airplanes, the accepted test methods for
compliance include:
a. Each test sample must consist of a
flat test specimen. A set of three
samples of the material must be tested.
The size of each sample must be 16
inches by 24 inches by 0.063 inches.
b. The test samples must be installed
into a steel sheet subframe with outside
dimensions of 18 inches by 32 inches.
The subframe must have an opening cut
into it of 14.5 inches by 22.5 inches. The
tests samples must be mounted onto the
subframe using .250–20 UNC threaded
bolts.
c. Test specimens must be
conditioned at 70 °F ± 5 °F and 55
percent ± 5 percent humidity for at least
24 hours before testing.
4. Demonstration of compliance will
be achieved if the material is not ignited
during any of the tests.
VerDate Mar<15>2010
16:47 Oct 30, 2013
Jkt 232001
[Docket No. FAA–2013–0858; Notice No.
25–13–09–SC]
Special Conditions: Bombardier Inc.,
Models BD–500–1A10 and BD–500–
1A11 Series Airplanes; Fuselage PostCrash Fire Survivability
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed special
conditions.
AGENCY:
This action proposes special
conditions for the Bombardier Inc.
Models BD–500–1A10 and BD–500–
1A11 series airplanes. These airplanes
will have a novel or unusual design
feature associated with aluminumlithium fuselage construction that may
provide different levels of protection
from post-crash fire threats than similar
aircraft constructed from traditional
aluminum structure. 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 December 16, 2013.
ADDRESSES: Send comments identified
by docket number FAA–2013–0858
using any of the following methods:
• Federal eRegulations Portal: Go to
https://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.
SUMMARY:
PO 00000
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Fmt 4702
Sfmt 4702
65233
• Fax: Fax comments to Docket
Operations at 202–493–2251.
Privacy: The FAA will post all
comments it receives, without change,
to https://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 https://DocketsInfo
.dot.gov/.
Docket: Background documents or
comments received may be read at
https://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:
Alan Sinclair, FAA, Airframe and Cabin
Safety Branch, ANM–115 Transport
Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington 98057–3356;
telephone 425–227–2195; facsimile
425–227–1232.
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 on or before the closing date for
comments. We may change these special
conditions based on the comments we
receive.
Background
On December 10, 2009, Bombardier
Inc. applied for a type certificate for
their new Models BD–500–1A10 and
BD–500–1A11 series airplanes (hereafter
collectively referred to as ‘‘C-series’’).
The C-series airplanes are swept-wing
monoplanes with a pressurized cabin.
They share an identical supplier base
and significant common design
elements. The fuselage is an aluminum
alloy material, blended double-bubble
design, sized for nominal 5-abreast
seating. Each airplane’s powerplant
E:\FR\FM\31OCP1.SGM
31OCP1
]]>Agencies
[Federal Register Volume 78, Number 211 (Thursday, October 31, 2013)]
[Proposed Rules]
[Pages 65231-65233]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-25663]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2013-0819; Notice No. 25-13-06-SC]
Special Conditions: Bombardier Inc., Models BD-500-1A10 and BD-
500-1A11 series airplanes; Fuselage In-Flight Fire Safety and
Flammability Resistance
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This action proposes special conditions for the Bombardier
Inc. Model BD-500-1A10 and BD-500-1A11 series airplanes. These
airplanes will have a novel or unusual design feature associated with
the materials used to fabricate the fuselage, which may affect fire
propagation during an in-flight fire. 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 December 16, 2013.
ADDRESSES: Send comments identified by docket number [FAA-2013-0819]
using any of the following methods:
Federal eRegulations Portal: Go to https://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 8 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 https://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 https://DocketsInfo.dot.gov/.
Docket: Background documents or comments received may be read at
https://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: Alan Sinclair, FAA, Airframe and Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98057-
3356; telephone 425-227-2195; facsimile 425-227-1232.
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 on or before the closing
date for comments. We may change these special conditions based on the
comments we receive.
Background
On December 10, 2009, Bombardier Inc. applied for a type
certificate for their new Model BD-500-1A10 and BD-500-1A11 series
airplanes. The Model BD-500-1A10 and BD-500-1A11 series airplanes are
swept-wing monoplanes with pressurized cabins, and they share an
identical supplier base and significant common design elements. The
fuselages are aluminum alloy material, blended double-bubble design,
sized for nominal 5 abreast seating. Each airplane's powerplant
includes two under-wing Pratt and Whitney PW1524G ultra-high bypass,
geared turbofan engines. Flight controls are fly-by-wire flight with
two passive/uncoupled side sticks. Avionics include five landscape
primary cockpit displays. The dimension of the airplanes encompasses a
wingspan of 115 feet; a height of 37.75 feet; and a length of 114.75
feet for the Model BD-500-1A10 and 127 feet for the Model BD-500-1A11.
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.
Maximum takeoff thrust is 21,000 pounds for the Model BD-500-1A10 and
23,300 pounds for the Model BD-500-1A11. The range is 3,394 miles
(5,463 kilometers) for both model airplanes. The maximum operating
altitude is 41,000 feet for both model airplanes.
The Bombardier BD-500-1A10 and BD-500-1A11 series airplanes will be
fabricated using aluminum-lithium materials. The performance of
airplanes consisting of a conventional aluminum fuselage in an
inaccessible in-flight fire scenario is understood based on service
history and extensive intermediate and large-scale fire testing. The
fuselage itself does not contribute to in-flight fire propagation. This
may not be the case for an all-aluminum-lithium fuselage. Experience
has shown that eliminating the fire propagation of the interior
materials and insulation materials tends to increase survivability
since other aspects of in-flight fire safety (e.g., toxic gas emission
and smoke obscuration) are typically by-products of the propagating
fire. The Bombardier BD-
[[Page 65232]]
500-1A10 and BD-500-1A11 series airplanes must provide protection
against an in-flight fire propagating along the surface of the
fuselage.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulations (14
CFR) 21.17, Bombardier Inc. must show that the Model BD-500-1A10 and
BD-500-1A11 series 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 Model BD-500-1A10 and BD-500-1A11
series 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 Model BD-500-1A10 and BD-500-1A11 series 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 Model BD-500-1A10 and BD-500-1A11 series airplanes will
incorporate the following novel or unusual design features: The
fuselage will be fabricated using aluminum-lithium materials instead of
conventional aluminum. This new type of material must provide
protection against an in-flight fire propagating along the surface of
the fuselage.
Discussion
The Bombardier BD-500-1A10 and BD-500-1A11 series airplanes will be
fabricated using aluminum-lithium materials. The performance of
airplanes consisting of a conventional aluminum fuselage in an
inaccessible in-flight fire scenario is understood based on service
history and extensive intermediate and large-scale fire testing.
Experience has shown that eliminating the fire propagation of the
interior materials and insulation materials tends to increase
survivability since other aspects of in-flight fire safety (e.g., toxic
gas emission and smoke obscuration) are typically by-products of the
propagating fire. The fuselage itself does not contribute to in-flight
fire propagation. This may not be the case for an all-aluminum-lithium
fuselage.
In the past, fatal in-flight fires have originated in inaccessible
areas of the airplane where thermal/acoustic insulation located
adjacent to the aluminum airplane skin has been the path for flame
propagation and fire growth. Concern over the fire performance of
thermal/acoustic insulation was initially raised by five incidents in
the 1990's, which revealed unexpected flame spread along the insulation
film that covered the thermal/acoustic insulation. In all cases, the
ignition source was relatively modest and, in most cases, was
electrical in origin (e.g., electrical short circuit, arcing caused by
chafed wiring, ruptured ballast case).
In 1996, the FAA Technical Center began a program to develop new
fire test criteria for insulation films directly relating to in-flight
fire resistance. The current test standard at that time was evaluated
as well as another small-scale test method that has been used by
airplane manufacturers to evaluate flame propagation on thermal/
acoustic insulation materials.
An inter-laboratory comparison of these methods revealed a number
of deficiencies. A new test method subjecting a material to a pilot
flame while the material is heated by a radiant panel was developed.
The new radiant panel test method and criteria were specifically
established to improve the evaluation of the in-flight fire ignition/
flame propagation of thermal/acoustic insulation materials based on
real-world fire scenarios. While these tests were developed for
thermal/acoustic insulation materials, this same type of test
methodology can be used to assess the flammability characteristics of
the proposed aluminum-lithium material for the fuselage.
The FAA reviewed the test method proposed by Bombardier Inc. and
determined that a larger flame and test article would be necessary to
make a determination of the potential flammability of the aluminum-
lithium material. It would also be more representative of a real-life
fire scenario.
The FAA recently conducted additional testing in our Components
Fire Test facility and determined that another way to assess the
survivability within the cabin of the Model BD-500-1A10 and BD-500-1A11
series is to use the cargo liner flammability test (part III of
appendix F to part 25, Test Method to Determine Flame Penetration
Resistance of Cargo Compartment Liners). However, the problem with
using this particular test is that when the aluminum panels melt,
molten globs of aluminum fall directly into the burner, which adversely
affects the flame. So the FAA decided that a similar test for the
measurement of insulation burnthrough resistance could be used (part
VII of appendix F to part 25, Test Method to Determine the Burnthrough
Resistance of Thermal/Acoustic Insulation Materials). Although this
test method uses the same burner as the cargo liner test, it uses a
slightly larger flame. In addition, the burner is not vertical, so
there was no problem with molten material falling into it, requiring
disassembly of the burner. The only slight change was the size of the
sample and the sample holder. These were modified slightly to
accommodate the samples that we received.
The recent FAA tests that were conducted in our Components Fire
Test facility used a 6 gallon/hour oil burner, the same apparatus used
to determine burnthrough resistance of thermal/acoustic insulation
(part VII of appendix F to part 25). The test used 16 by 24 inch Al-Li
panels that were installed into a sheet steel subframe, which measured
18 by 32 inches (outside dimensions). The subframe had an opening cut
into it, which measured 14.5 by 22.5 inches; this allowed the test
panels to be mounted onto the subframe using .250-20 UNC threaded
bolts.
The FAA proposes that Bombardier use the test method contained in
part VII of appendix F to part 25, Test Method to Determine the
Burnthrough Resistance of Thermal/Acoustic Insulation Materials, with
the slight changes to the sample size and sample holder as an alternate
test method to show compliance with applicable requirements. Bombardier
Inc. is responsible for finding a suitable testing facility in which to
conduct the testing.
Applicability
As discussed above, these special conditions are applicable to the
Model BD-500-1A10 and BD-500-1A11 airplanes. Should Bombardier Inc.
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.
[[Page 65233]]
Conclusion
This action affects only certain novel or unusual design features
on two models 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 Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for Bombardier Inc. Model BD-500-1A10 and BD-500-1A11 series airplanes.
1. Fuselage In-Flight Fire Safety and Flammability Resistance.
Bombardier must demonstrate that the fuselage would not materially
contribute to the propagation of an in-flight fire or introduce any
additional in-flight fire risk.
2. To demonstrate compliance, the test set-up and methodology must
be commensurate with 14 CFR part 25, appendix F, part VII, except the
size of the test samples, modifications to the sample holder, and the
test methodology would be varied as described below.
3. In demonstrating that the aluminum-lithium material used to
fabricate the fuselage has equal or better flammability resistance
characteristics than the aluminum alloy sheet typically used as skin
material on similar airplanes, the accepted test methods for compliance
include:
a. Each test sample must consist of a flat test specimen. A set of
three samples of the material must be tested. The size of each sample
must be 16 inches by 24 inches by 0.063 inches.
b. The test samples must be installed into a steel sheet subframe
with outside dimensions of 18 inches by 32 inches. The subframe must
have an opening cut into it of 14.5 inches by 22.5 inches. The tests
samples must be mounted onto the subframe using .250-20 UNC threaded
bolts.
c. Test specimens must be conditioned at 70 [deg]F 5
[deg]F and 55 percent 5 percent humidity for at least 24
hours before testing.
4. Demonstration of compliance will be achieved if the material is
not ignited during any of the tests.
Issued in Renton, Washington, on September 12, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2013-25663 Filed 10-30-13; 8:45 am]
BILLING CODE 4910-13-P
