[Federal Register Volume 71, Number 239 (Wednesday, December 13, 2006)]
[Rules and Regulations]
[Pages 74755-74758]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-21188]



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  Federal Register / Vol. 71, No. 239 / Wednesday, December 13, 2006 / 
Rules and Regulations  

[[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.

-----------------------------------------------------------------------

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]
BILLING CODE 4910-13-P