[Federal Register: December 13, 2006 (Volume 71, Number 239)]
[Rules and Regulations]
[Page 74755-74758]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13de06-1]
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Rules and Regulations
Federal Register
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[[Page 74755]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM352; Special Conditions No. 25-339-SC]
Special Conditions: Airbus Model A380-800 Airplane, Lithium Ion
Battery Installation
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the Airbus A380-800
airplane. This airplane will have novel or unusual design features when
compared to the state of technology envisioned in the airworthiness
standards for transport category airplanes. The Airbus A380-800 will
incorporate the use of high capacity lithium ion battery technology in
on-board systems. For this design feature, the applicable airworthiness
regulations do not contain adequate or appropriate safety standards
regarding lithium ion batteries. 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: The effective date of these special conditions
is November 30, 2006.
FOR FURTHER INFORMATION CONTACT: Holly Thorson, FAA, International
Branch, ANM-116, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone
(425) 227-1357; facsimile (425) 227-1149.
SUPPLEMENTARY INFORMATION:
Background
Airbus applied for FAA certification/validation of the
provisionally-designated Model A3XX-100 in its letter AI/L 810.0223/98,
dated August 12, 1998, to the FAA. Application for certification by the
Joint Aviation Authorities (JAA) of Europe had been made on January 16,
1998, reference AI/L 810.0019/98. In its letter to the FAA, Airbus
requested an extension to the 5-year period for type certification in
accordance with 14 CFR 21.17(c). The request was for an extension to a
7-year period, using the date of the initial application letter to the
JAA as the reference date. The reason given by Airbus for the request
for extension is related to the technical challenges, complexity, and
the number of new and novel features on the airplane. On November 12,
1998, the Manager, Aircraft Engineering Division, AIR-100, granted
Airbus' request for the 7-year period, based on the date of application
to the JAA.
In its letter AI/LE-A 828.0040/99 Issue 3, dated July 20, 2001,
Airbus stated that its target date for type certification of the Model
A380-800 has been moved from May 2005, to January 2006, to match the
delivery date of the first production airplane. In a subsequent letter
(AI/L 810.0223/98 issue 3, January 27, 2006), Airbus stated that its
target date for type certification is October 2, 2006. In accordance
with 14 CFR 21.17(d)(2), Airbus chose a new application date of
December 20, 1999, and requested that the 7-year certification period
which had already been approved be continued. The FAA has reviewed the
part 25 certification basis for the Model A380-800 airplane, and no
changes are required based on the new application date.
The Model A380-800 airplane will be an all-new, four-engine jet
transport airplane with a full double-deck, two-aisle cabin. The
maximum takeoff weight will be 1.235 million pounds with a typical
three-class layout of 555 passengers.
Type Certification Basis
Under the provisions of 14 CFR 21.17, Airbus must show that the
Model A380-800 airplane meets the applicable provisions of 14 CFR part
25, as amended by Amendments 25-1 through 25-98. If the Administrator
finds that the applicable airworthiness regulations do not contain
adequate or appropriate safety standards for the Airbus A380-800
airplane because of novel or unusual design features, special
conditions are prescribed under the provisions of 14 CFR 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Airbus Model A380-800 airplane must comply with the
fuel vent and exhaust emission requirements of 14 CFR 34 and the noise
certification requirements of 14 CFR part 36. In addition, the FAA must
issue a finding of regulatory adequacy pursuant to section 611 of
Public Law 93-574, the ``Noise Control Act of 1972.''
Special conditions, as defined in 14 CFR 11.19, are issued in
accordance with 14 CFR 11.38 and become part of the type certification
basis in accordance with 14 CFR 21.17(a)(2).
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 the provisions of 14 CFR 21.101.
Discussion of Novel or Unusual Design Features
Statement of Issue
The Airbus A380-800 airplane will use lithium ion batteries for its
emergency lighting system. Large, high capacity, rechargeable lithium
ion batteries are a novel or unusual design feature in transport
category airplanes. This type of battery has certain failure,
operational, and maintenance characteristics that differ significantly
from those of the nickel-cadmium and lead-acid rechargeable batteries
currently approved for installation on large transport category
airplanes. The FAA is proposing this special condition to require that
(1) All characteristics of the lithium ion battery and its installation
that could affect safe operation of the Airbus A380-800 airplane are
addressed, and (2) appropriate maintenance requirements are established
to ensure the availability of electrical power from the batteries when
needed.
Background
The current regulations governing installation of batteries in
large
[[Page 74756]]
transport category airplanes were derived from Civil Air Regulations
(CAR) Part 4b.625(d) as part of the re-codification of CAR 4b that
established 14 CFR Part 25 in February, 1965. The new battery
requirements, 14 CFR 25.1353(c)(1) through (c)(4), basically reworded
the CAR requirements.
Increased use of nickel-cadmium batteries in small airplanes
resulted in increased incidents of battery fires and failures which led
to additional rulemaking affecting large transport category airplanes
as well as small airplanes. On September 1, 1977 and March 1, 1978,
respectively the FAA issued 14 CFR 25.1353c(5) and c(6), governing
nickel-cadmium battery installations on large transport category
airplanes.
The proposed use of lithium ion batteries for the emergency
lighting system on the Airbus A380 airplane has prompted the FAA to
review the adequacy of these existing regulations. Our review indicates
that the existing regulations do not adequately address several
failure, operational, and maintenance characteristics of lithium ion
batteries that could affect the safety and reliability of the Airbus
A380's lithium ion battery installation.
At present, there is limited experience with use of rechargeable
lithium ion batteries in applications involving commercial aviation.
However, other users of this technology, ranging from wireless
telephone manufacturers to the electric vehicle industry, have noted
safety problems with lithium ion batteries. These problems include
overcharging, over-discharging, and flammability of cell components.
1. Overcharging
In general, lithium ion batteries are significantly more
susceptible to internal failures that can result in self-sustaining
increases in temperature and pressure (i.e., thermal runaway) than
their nickel-cadmium or lead-acid counterparts. This is especially true
for overcharging which causes heating and destabilization of the
components of the cell, leading to the formation (by plating) of highly
unstable metallic lithium. The metallic lithium can ignite, resulting
in a self-sustaining fire or explosion. Finally, the severity of
thermal runaway due to overcharging increases with increasing battery
capacity due to the higher amount of electrolyte in large batteries.
2. Over-discharging
Discharge of some types of lithium ion batteries beyond a certain
voltage (typically 2.4 volts) can cause corrosion of the electrodes of
the cell, resulting in loss of battery capacity that cannot be reversed
by recharging. This loss of capacity may not be detected by the simple
voltage measurements commonly available to flight crews as a means of
checking battery status--a problem shared with nickel-cadmium
batteries.
3. Flammability of Cell Components
Unlike nickel-cadmium and lead-acid batteries, some types of
lithium ion batteries use liquid electrolytes that are flammable. The
electrolyte can serve as a source of fuel for an external fire, if
there is a breach of the battery container.
These problems experienced by users of lithium ion batteries raise
concern about the use of these batteries in commercial aviation. The
intent of the proposed special condition is to establish appropriate
airworthiness standards for lithium ion battery installations in the
Airbus A380-800 airplane and to ensure, as required by 14 CFR 25.601,
that these battery installations are not hazardous or unreliable. To
address these concerns, the proposed special conditions adopt the
following requirements:
Those sections of 14 CFR 25.1353 that are applicable to
lithium ion batteries.
The flammable fluid fire protection requirements of 14 CFR
25.863. In the past, this rule was not applied to batteries of
transport category airplanes, since the electrolytes utilized in lead-
acid and nickel-cadmium batteries are not flammable.
New requirements to address the hazards of overcharging
and over-discharging that are unique to lithium ion batteries.
New maintenance requirements to ensure that batteries used
as spares are maintained in an appropriate state of charge.
Discussion of Comments
Notice of Proposed Special Conditions No. 25-06-08-SC, pertaining
to the lithium ion battery installation in the Airbus A380 airplane,
was published in the Federal Register on September 7, 2006. Comments
were received from Acme Electric Corporation and the Airline Pilots
Association (ALPA). In addition, comments submitted to the European
Aviation Safety Agency (EASA) by the Civil Aviation Authority of the
United Kingdom were sent to the FAA by EASA.
Comments From Acme Electric Corporation
Requested change 1: The commenter suggests that `` * * * charging
in environments of less than 0 [deg]C [degrees Celsius] will need to be
addressed; several references have stated that Lithium metal may plate
onto the anode if charged in this environment.''
FAA response: Paragraph 1 of the special conditions addresses
charging environment by requiring that ``safe cell temperatures and
pressures must be maintained during any foreseeable charging or
discharging condition.'' We consider charging in environments of less
than 0 degrees C to be foreseeable. In our judgment, therefore, this
concern is adequately addressed by the special conditions, as proposed.
Requested change 2: The commenter indicates that the special
conditions should address the effects of a short circuit in the battery
on the battery itself and on its surroundings.
FAA response: This issue is addressed in Paragraphs 1 and 6 of the
special conditions. Paragraph 1 specifies that
Safe cell temperatures and pressures must be maintained during
any foreseeable charging or discharging condition and during any
failure of the charging or battery monitoring system not shown to be
extremely remote. The lithium ion battery installation must preclude
explosion in the event of those failures.
Paragraph 6 specifies that
Each lithium ion battery installation must have provisions to
prevent any hazardous effect on structure or essential systems
caused by the maximum amount of heat the battery can generate during
a short circuit of the battery or of its individual cells.
We consider short circuits in the battery to be a failure that is
covered by these special conditions.
Requested change 3: The commenter also states that ``At the present
time, Lithium Ion batteries require non-passive electronics and/or
software as an integral part of the assembly; therefore, additional
requirements of 14 CFR 25.1309, 25.1316 and 25.1431 are also needed.''
FAA response: The requirements of Sec. 25.1309, 25.1316, and
25.1431 do apply to the lithium ion battery installation. The special
conditions specify additional requirements that are needed, but not
already provided by the part 25 requirements in the A380 certification
basis.
Comments From the Airline Pilots Association
The Airline Pilots Association (ALPA) conditionally supports the
FAA's proposal for special conditions for
[[Page 74757]]
lithium ion batteries on the A380-800 aircraft, but ``strongly
maintains that there needs to be adequate protections and procedures in
place to ensure that concerns regarding lithium ion batteries are fully
addressed and protected against.'' Appended to the ALPA comments was a
copy of FAA report DOT/FAA/AR-06/38, September 2006, Flammability
Assessment of Bulk-Packed, Rechargeable Lithium-Ion Cells in Transport
Category Aircraft. With the knowledge of the safety hazards described
in the appended report and by others, ALPA requested that the FAA
consider the specific concerns discussed below.
Requested change 4: The commenter requests that Paragraph 3 of the
special conditions be revised to ensure that the certification design
of the A380 prevents explosive or toxic gasses emitted by a lithium ion
battery from entering the cabin. The commenter also requests that the
FAA assure that flight crew procedures and training are adequate to
protect both passengers and crew, if explosive or toxic gasses do enter
the cabin.
FAA response: The FAA has no regulations that prohibit smoke or
gasses from electrical equipment in the electrical equipment bays from
entering the flightdeck or passenger cabins. However, 14 CFR 25.857
prohibits hazardous quantities of smoke, flames, or extinguishing
agents from cargo compartments from entering any compartment occupied
by the crew or passengers.
Paragraph (3) of these special conditions specifies that
No explosive or toxic gasses emitted by any lithium ion battery
in normal operation or as the result of any failure of the battery
charging system, monitoring system, or battery installation--not
shown to be extremely remote--may accumulate in hazardous quantities
within the airplane.''
The special conditions require that any explosive or toxic gasses
emitted by a lithium ion battery be limited to less than hazardous
quantities anywhere on the airplane. (A separate set of special
conditions pertaining to fire protection for the A380 requires a
demonstration of means to prevent hazardous quantities of smoke
originating from an electrical equipment bay from penetrating into the
flightdeck or passenger cabins.)
Finally, FAA operational requirements ensure that all crewmembers
receive adequate training in both normal and emergency equipment and
procedures. Flight attendants are cognizant of cabin environmental
conditions and are trained to report smoke or fumes in the cabin.
Flightdeck crew are aware of emergency procedures for responding to
smoke, gasses, or fumes from known or unknown sources.
Requested change 5: The commenter states,
We are very concerned with a fire erupting in flight, and being
able to rapidly extinguish it. The Special Conditions should require
that there be a means provided to apply extinguishing agents by the
flight (cabin) crew instead of promoting it as an option in managing
the threat posed by the use of lithium-ion batteries. ALPA maintains
that the petitioner must provide means for extinguishing fires that
occur vs. listing it as an option in Sec. 25.863.
FAA response: The FAA shares the commenter's concern over a fire
erupting in flight. We have concluded that providing a means for
controlling or extinguishing a fire--such as stopping the flow of
fluids, shutting down equipment, or fireproof containment, as described
in paragraph (4) of 14 CFR 25.863--is an adequate alternative to
requiring the flight or cabin crew to use extinguishing agents.
Requested change 6: The commenter suggests that the special
conditions address means to ensure that the lithium ion batteries do
not overheat or overcharge in the event of failure or malfunction of
the automatic disconnect function, when a means of disconnecting the
batteries from the charging source is not available.
FAA response: The FAA agrees that there should be a means to
prevent overheating or overcharging of lithium ion batteries in the
event of failure or malfunction of the automatic disconnect function,
described in Paragraph (7). Paragraphs (1), (2), and (6) of these
special conditions address the issue of failure modes of the lithium
ion batteries.
Requested change 7: Finally, ALPA commented on monitoring and
warning features that will indicate when the state-of-charge of the
batteries has fallen below levels considered acceptable for dispatch of
the airplane. The commenter suggested that the special conditions
address the location of the warning indication; whether it is displayed
to the captain, the crew, or both; and the training to be incorporated
in the crew training programs.
FAA response: Flightdeck warning indicators associated with the
state of charge of the lithium ion battery and appropriate training of
the crew will be addressed during certification as part of the flight
deck evaluation. As required by Sec. 25.1309(c), this evaluation will
ensure that the warning indication is effective and appropriate for the
hazard.
Comments From the Civil Aviation Authority of the United Kingdom (UK
CAA)
Requested change 8: In its comments to EASA, the UK CAA states that
Paragraph 5 of the special conditions should be revised to read as
follows:
No fluids or gasses that may escape from any Li-ion battery may
be allowed to damage surrounding aeroplane structure, or any
adjacent systems or equipment, including electrical wiring, in such
a way as to hazard the aeroplane.
The UK CAA indicates that Paragraph 5, as proposed, specifies that
no escaping corrosive fluids or gasses may damage aeroplane structures
or adjacent essential equipment. The reasons for this are obvious, and
the requirement is fully supported. However, it is noted that CS/JAR
25.1309 [EASA and Joint Aviation Authority regulation 25.1309] in its
title makes a distinction between equipment and systems. Thus a
requirement that specifies protection only for essential equipment
could be misinterpreted as not applying to essential systems. For
absolute clarity, this requirement should be extended to show that it
applies to both essential equipment and essential systems.
Furthermore, corrosive fluids and gasses could also damage any non-
essential electrical equipment or electrical wiring in such a way as to
cause short circuits or arcing that could itself pose a hazard to the
aeroplane. For completeness, this requirement should also seek to
preclude damage to any adjacent electrical equipment or wiring whose
failure could present a hazard to the airplane.
FAA Response: The wording of Paragraph (5) is identical to that of
14 CFR 25.1353(c)(4), applicable to all batteries. For clarity, we will
revise the text to read as follows:
No corrosive fluids or gasses that may escape from any lithium
ion battery may damage surrounding structure or any adjacent
systems, equipment or electrical wiring of the airplane in such a
way as to cause a major or more severe failure condition, in
accordance with 14 CFR 25.1309 (b) and applicable regulatory
guidance.
Requested change 9: The UK CAA also commented to EASA that
Paragraph 9 of the Special Conditions should be revised to read ``The
instructions for Continued Airworthiness, required by 14 CFR 25.1529,
must contain maintenance requirements for * * *.''
FAA Response: The FAA concurs with this editorial comment and has
revised the text of Paragraph 9 of the Special Conditions accordingly.
[[Page 74758]]
Applicability
As discussed above, these special conditions are applicable to the
Airbus A380-800 airplane. Should Airbus apply at a later date for a
change to the type certificate to include another model incorporating
the same novel or unusual design features, these special conditions
would apply to that model as well under the provisions of Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
of the Airbus A380-800 airplane. It is not a rule of general
applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
0
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 the Airbus A380-800 airplane.
In lieu of the requirements of 14 CFR 25.1353(c)(1) through (c)(4),
the following special conditions apply:
Lithium-ion batteries on the Airbus Model 380-800 airplane must be
designed and installed as follows:
(1) Safe cell temperatures and pressures must be maintained during
any foreseeable charging or discharging condition and during any
failure of the charging or battery monitoring system not shown to be
extremely remote. The lithium ion battery installation must preclude
explosion in the event of those failures.
(2) Design of the lithium ion batteries must preclude the
occurrence of self-sustaining, uncontrolled increases in temperature or
pressure.
(3) No explosive or toxic gasses emitted by any lithium ion battery
in normal operation or as the result of any failure of the battery
charging system, monitoring system, or battery installation--not shown
to be extremely remote--may accumulate in hazardous quantities within
the airplane.
(4) Installations of lithium ion batteries must meet the
requirements of 14 CFR 25.863(a) through (d).
(5) No corrosive fluids or gasses that may escape from any lithium
ion battery may damage surrounding structure or any adjacent systems,
equipment or electrical wiring of the airplane in such a way as to
cause a major or more severe failure condition, in accordance with 14
CFR 25.1309 (b) and applicable regulatory guidance.
(6) Each lithium ion battery installation must have provisions to
prevent any hazardous effect on structure or essential systems caused
by the maximum amount of heat the battery can generate during a short
circuit of the battery or of its individual cells.
(7) Lithium ion battery installations must have a system to control
the charging rate of the battery automatically, so as to prevent
battery overheating or overcharging, and,
(i) A battery temperature sensing and over-temperature warning
system with a means for automatically disconnecting the battery from
its charging source in the event of an over-temperature condition, or,
(ii) A battery failure sensing and warning system with a means for
automatically disconnecting the battery from its charging source in the
event of battery failure.
(8) Any lithium ion battery installation whose function is required
for safe operation of the airplane must incorporate a monitoring and
warning feature that will provide an indication to the appropriate
flight crewmembers, whenever the state-of-charge of the batteries has
fallen below levels considered acceptable for dispatch of the airplane.
(9) The Instructions for Continued Airworthiness, required by 14
CFR 25.1529, must contain maintenance requirements for measurements of
battery capacity at appropriate intervals to ensure that batteries
whose function is required for safe operation of the airplane will
perform their intended function as long as the battery is installed in
the airplane. The Instructions for Continued Airworthiness must also
contain procedures for the maintenance of lithium ion batteries in
spares storage to prevent the replacement of batteries whose function
is required for safe operation of the airplane with batteries that have
experienced degraded charge retention ability or other damage due to
prolonged storage at a low state of charge.
Note: These special conditions are not intended to replace 14
CFR 25.1353(c) in the certification basis of the Airbus A380-800
airplane. The special conditions apply only to lithium ion batteries
and their installations. The requirements of 14 CFR 25.1353(c)
remain in effect for batteries and battery installations of the
Airbus A380-800 airplane that do not utilize lithium ion batteries.
Issued in Renton, Washington, on November 30, 2006.
Kevin Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E6-21188 Filed 12-12-06; 8:45 am]
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