[Federal Register Volume 73, Number 235 (Friday, December 5, 2008)]
[Rules and Regulations]
[Pages 73997-73999]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-28876]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM393; Special Conditions No. 25-377-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: Final special conditions.

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SUMMARY: These special conditions are issued 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 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: January 5, 2009.

FOR FURTHER INFORMATION CONTACT: Nazih Khaouly, FAA, Airplane and 
Flight Crew Interface Branch, 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:

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

[[Page 73998]]

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 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.

Discussion of Comments

    A Notice of proposed special conditions No. 25-08-06-SC for the 
Airbus A318, A319, A320 and A321 series airplanes modified by L2 
Consulting Services was published in the Federal Register on August 7, 
2008 (73 FR 45886). One comment was received from Deutsche Lufthansa, 
AG.
    Comment: Lufthansa states that additional testing on Class 1 and 
Class 2 electronic flight bags will add cost without providing higher 
degrees of safety.
    FAA Disposition: Lufthansa's comments refer to Class 1 and 2 
electronic flight bags. The classes of electronic flight bags are 
defined in Advisory Circular 91-78: ``Physical EFB displays may be 
portable (Class 1), attached to a mounting device (Class 2), or built 
into the aircraft (Class 3).'' The electronic flight bags to which 
these special conditions apply are Class 3 electronic flight bags which 
are permanently installed equipment. Therefore, the comments is not 
applicable. The special conditions are issued as proposed.

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

[[Page 73999]]

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.

PART 25--[AMENDED]

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

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the supplemental type certificate for the Airbus A318, A319, A320 and 
A321 series airplanes, modified by L2 Consulting Services.
    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).
    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 
spare 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 that the battery 
will retain enough of a charge, expressed in ampere-hours, to ensure 
that the battery cells will not be damaged. A battery cell may be 
damaged by lowering the charge below a point where there is a 
reduction in the ability to charge and retain a full charge. This 
reduction would be greater than the reduction 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 November 28, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-28876 Filed 12-4-08; 8:45 am]
BILLING CODE 4910-13-P