[Federal Register: August 7, 2008 (Volume 73, Number 153)]
[Proposed Rules]
[Page 45886-45888]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07au08-13]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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[[Page 45886]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM393; Notice No. 25-08-06-SC]
Special Conditions: Airbus A318, A319, A320, and A321 Series
Airplanes; Astronautics Electronic Flight Bags With Lithium Battery
Installations
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This action proposes special conditions for the Airbus A318,
A319, A320, and A321 series airplanes. These airplanes, as modified by
L2 Consulting Services, will have a novel or unusual design feature
associated with Astronautics electronic flight bags which use lithium
battery technology. 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: We must receive your comments by September 22, 2008.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attention:
Rules Docket (ANM-113), Docket No. NM393, 1601 Lind Avenue, SW.,
Renton, Washington 98057-3356. You may deliver two copies to the
Transport Airplane Directorate at the above address. You must mark your
comments: Docket No. NM393. You can inspect comments in the Rules
Docket weekdays, except federal holidays, between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Nazih Khaouly, FAA, Airplane and
Flight Crew Interface, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone (425) 227-2432; facsimile (425) 227-
1149.
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 ask
that you send us two copies of written comments.
We will file in the docket all comments we receive as well as a
report summarizing each substantive public contact with FAA personnel
about these special conditions. You can inspect the docket before and
after the comment closing date. If you wish to review the docket in
person, go to the address in the ADDRESSES section of this preamble
between 7:30 a.m. and 4 p.m., Monday through Friday, except federal
holidays.
We will consider all comments we receive by the closing date for
comments. We will consider comments filed late, if it is possible to do
so without incurring expense or delay. We may change these special
conditions based on the comments we receive.
If you want us to let you know we received your comments on this
proposal, send us a pre-addressed, stamped postcard on which the docket
number appears. We will stamp the date on the postcard and mail it back
to you.
Background
On March 12, 2007, L2 Consulting Services of Dripping Springs,
Texas, applied for a supplemental type certificate to install
Astronautics electronic flight bags on Airbus A318, A319, A320, and
A321 series airplanes. In addition to lithium batteries, the
Astronautics electronic flight bags contain the following equipment:
Multiple electronic flight bag display units,
Multiple electronic units (computer),
Electronic flight bag power On/Off switches, and
Mounting arms and mounting brackets.
At present, there is limited experience with use of rechargeable
lithium 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 batteries. These problems include
overcharging, over-discharging, and flammability of cell components.
1. Overcharging
In general, lithium 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 that 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 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 flightcrews 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 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 batteries raise
concern about the use of these batteries in commercial aviation.
Accordingly, the proposed use of lithium batteries in Astronautics
electronic flight bags on Airbus A318, A319, A320, and A321 series
airplanes has prompted the FAA to review the adequacy of existing
regulations in Title 14 Code of Federal Regulations (14 CFR) part 25.
Our review indicates that the
[[Page 45887]]
existing regulations do not adequately address several failure,
operational, and maintenance characteristics of lithium batteries that
could affect the safety and reliability of lithium battery
installations.
The intent of these special conditions is to establish appropriate
airworthiness standards for lithium batteries in Airbus A318, A319,
A320, and A321 series airplanes modified by L2 Consulting Services, and
to ensure, as required by Sec. 25.601, that these battery
installations are not hazardous or unreliable. Accordingly, these
special conditions include the following requirements:
Those provisions of Sec. 25.1353 which are applicable to
lithium batteries.
The flammable fluid fire protection provisions of Sec.
25.863.
In the past, this regulation was not applied to batteries of
transport category airplanes, since the electrolytes used 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 batteries.
New Instructions for Continuous Airworthiness that include
maintenance requirements to ensure that batteries used as spares are
maintained in an appropriate state of charge.
Type Certification Basis
Under the provisions of 14 CFR 21.101, L2 Consulting Services must
show that the Airbus A318, A319, A320, and A321 series airplanes, as
changed, continue to meet the applicable provisions of the regulations
incorporated by reference in Type Certificate No. A28NM or the
applicable regulations in effect on the date of application for the
change. The regulations incorporated by reference in the type
certificate are commonly referred to as the ``original type
certification basis.''
The certification basis for Airbus A318, A319, A320, and A321
series airplanes includes applicable sections of part 25, effective
February 1, 1965, as amended by Amendments 25-1 through 25-56, plus
other amendments for each model as indicated in Type Certificate No.
A28NM. In addition, the certification basis includes certain special
conditions, exemptions, equivalent levels of safety, or later amended
sections of the applicable part 25 that are not relevant to these
special conditions.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for Airbus A318, A319, A320, and A321
series airplanes because of a novel or unusual design feature, special
conditions are prescribed under the provisions of 14 CFR 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Airbus A318, A319, A320, and A321 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.
The FAA issues special conditions, as defined in 14 CFR 11.19,
under Sec. 11.38, and they become part of the type certification basis
in accordance with Sec. 21.101.
Special conditions are initially applicable to the models for which
they are issued. Should L2 Consulting Services apply for a supplemental
type certificate to modify any other model included on Type Certificate
No. A28NM to incorporate the same or similar novel or unusual design
feature, these special conditions would also apply to the other model.
Novel or Unusual Design Features
The Airbus A318, A319, A320, and A321 series airplanes, as modified
by L2 Consulting Services, to include Astronautics electronic flight
bags which use lithium battery technology, will incorporate a novel or
unusual design feature. Because of rapid improvements in airplane
technology, 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.
The Astronautics electronic flight bags will include lithium
battery installations. Large, high capacity, rechargeable lithium
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 issues
these special conditions to require that all characteristics of the
lithium battery and its installation do not adversely affect the safe
operation of the airplane.
Applicability
As discussed above, these special conditions are applicable to the
Airbus A318, A319, A320, and A321 series airplanes as modified by L2
Consulting Services. Should L2 Consulting Services apply at a later
date for a supplemental type certificate to modify any other model
included on Type Certificate No. A28NM to incorporate 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
of the Airbus A318, A319, A320, and A321 series airplanes as modified
by L2 Consulting Services. It is not a rule of general applicability
and affects only the applicant which applied to the FAA for approval of
these features on the airplane.
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 the Airbus A318, A319, A320, and A321 series airplanes modified by
L2 Consulting Services in lieu of the requirements of Sec.
25.1353(c)(1) through (c)(4), Amendment 25-113.
Lithium batteries and battery installations on Airbus A318, A319,
A320, and A321 series airplanes 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 battery installation must preclude
explosion in the event of those failures.
2. Design of the lithium batteries must preclude the occurrence of
self-sustaining, uncontrolled increases in temperature or pressure.
3. No explosive or toxic gases emitted by any lithium battery in
normal operation or as the result of any failure of the battery
charging system, monitoring system, or battery installation which is
not shown to be extremely remote may accumulate in hazardous quantities
within the airplane.
4. Installations of lithium batteries must meet the requirements of
Sec. 25.863(a) through (d).
[[Page 45888]]
5. No corrosive fluids or gases that may escape from any lithium
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
Sec. 25.1309(b) and applicable regulatory guidance.
6. Each lithium 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 battery installations must have a system to control the
charging rate of the battery automatically, so as to prevent battery
overheating or overcharging, and,
(a) 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
(b) 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 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 Sec.
25.1529 must contain maintenance requirements to assure that the
lithium battery is sufficiently charged at appropriate intervals
specified by the battery manufacturer to ensure that batteries whose
function is required for safe operation of the airplane will not
degrade below specified ampere-hour levels sufficient to power the
electronic flight bag applications that are required for continued safe
flight and landing. The Instructions for Continued Airworthiness must
also contain procedures for the maintenance of lithium 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. Precautions should be
included in the Instructions for Continued Airworthiness maintenance
instructions to prevent mishandling of the lithium battery which could
result in short-circuit or other unintentional damage that could result
in personal injury or property damage.
Note 1: The term ``sufficiently charged'' means a charge that is
above a minimum level, expressed in ampere-hours, below which the
battery will reduce its capacity to be fully charged and/or the
ability to retain a complete charge. This reduction in charging and
retaining a full charge capacity is below the original design
capacity that may result from normal operational degradation.
Note 2: These special conditions are not intended to replace
Sec. 25.1353(c), Amendment 25-113 in the certification basis of the
L2 Consulting Services supplemental type certificate. These special
conditions apply only to lithium batteries and their installations.
The requirements of Sec. 25.1353(c), Amendment 25-113 remain in
effect for batteries and battery installations on the L2 Consulting
Services supplemental type certificate that do not use lithium
batteries.
Compliance with the requirements of these special conditions must
be shown by test or analysis, with the concurrence of the Fort Worth
Special Certification Office.
Issued in Renton, Washington, on July 29, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-18139 Filed 8-6-08; 8:45 am]
BILLING CODE 4910-13-P