[Federal Register Volume 76, Number 180 (Friday, September 16, 2011)]
[Rules and Regulations]
[Pages 57625-57627]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-23720]



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  Federal Register / Vol. 76, No. 180 / Friday, September 16, 2011 / 
Rules and Regulations  

[[Page 57625]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

 [Docket No. NM464; Notice No. 25-445-SC]


Special Conditions: Boeing Model 737-600, -700, -700C, -800, -
900, and -900ER Series Airplanes; Rechargeable Lithium-Ion Battery 
Installations

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Boeing Model 737-
600, -700, -700C, -800, -900, and -900ER series airplanes. These 
airplanes, as modified by Electronic Cable Specialists, Inc., will have 
a novel or unusual design feature associated with the installation of a 
dual Class 3 electronic flight bag (EFB) system that contains 
rechargeable lithium-ion batteries. 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: The effective date of these special conditions is September 9, 
2011. We must receive your comments by October 31, 2011.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM464, 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. NM464. 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, ANM-111, Transport 
Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, 
SW., Renton, Washington 98057-3356; telephone (425) 227-2432; facsimile 
(425) 227-1232.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions are 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
aircraft. In addition, the substance of these special conditions has 
been subject to the public-comment process in several prior instances 
with no substantive comments received. The FAA therefore finds that 
good cause exists for making these special conditions effective upon 
issuance.

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 
concerning 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 on or before 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 acknowledge receipt of your comments on this 
proposal, include with your comments a self-addressed, stamped postcard 
on which you have written the docket number. We will stamp the date on 
the postcard and mail it back to you.

Background

    On September 30, 2009, Electronic Cable Specialists, Inc., applied 
for a supplemental type certificate for a dual Class 3 EFB system on 
the Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes. The EFB system will contain lithium batteries in the EFB 
electronic display unit (EDU).

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.101, Electronic Cable Specialists, Inc., must show that the 
Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes, as changed, continue to meet the applicable provisions of 
the regulations incorporated by reference in A16WE 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 the Boeing Model 737 airplanes affected by 
this modification is as follows:
    For 737-600, -700, and -800 series airplanes: 14 CFR part 25 as 
amended by Amendments 25-1 through 25-77, with the exemptions and 
special conditions listed on type certificate A16WE.
    For 737-700C and -900 series airplanes: 14 CFR part 25 as amended 
by Amendments 25-1 through 25-91, with the exemptions and special 
conditions listed on type certificate A16WE.
    For 737-900ER series airplanes: 14 CFR part 25 as amended by 
Amendments 25-1 through 25-108, with the exemptions and special 
conditions listed on type certificate A16WE.
    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 Boeing Model 737-600, -700, -700C, 
-800, -900, and -900ER series airplanes modified by Electronic Cable 
Specialists, Inc., 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

[[Page 57626]]

conditions, the Boeing Model 737-600, -700, -700C, -800, -900, and -
900ER 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, in 
accordance with Sec.  11.38, and they become part of the type-
certification basis under 14 CFR 21.101.
    Special conditions are initially applicable to the model for which 
they are issued. Should Electronic Cable Specialists, Inc., apply for a 
supplemental type certificate to modify any other model included on 
type certificate A16WE to incorporate the same or similar novel or 
unusual design feature, the special conditions would also apply to the 
other model under Sec.  21.101.

Novel or Unusual Design Features

    Electronic Cable Specialists, Inc., proposes to use rechargeable 
lithium-ion batteries in a dual Class 3 EFB system on Boeing Model 737-
600, -700, -700C, -800, -900, and -900ER series airplanes. This type of 
battery possesses certain failure and operational characteristics, and 
maintenance requirements differ significantly from that of the nickel-
cadmium (Ni-Cd) and lead-acid rechargeable batteries currently approved 
for installation in large, transport-category airplanes. Small, low-
capacity, rechargeable lithium batteries are a novel or unusual design 
feature in transport-category airplanes, and current regulations in 14 
CFR part 25 do not address installation of rechargeable lithium 
batteries.

Discussion

    The current regulations governing installation of batteries in 
large, 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, Sec.  25.1353(c)(1) through (c)(4), basically reworded 
the CAR requirements.
    Increased use of Ni-Cd batteries in small airplanes resulted in 
increased frequency 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, the 
FAA issued Sec.  25.1353(c)(5) and (c)(6), respectively, which govern 
Ni-Cd battery installations on large, transport-category airplanes.
    The proposed use of rechargeable lithium batteries for equipment on 
the Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes 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 batteries that could affect the safety and 
reliability of rechargeable lithium-battery installations on the Boeing 
Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes.
    The use of lithium rechargeable batteries in applications involving 
commercial aviation has limited history. 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 
lithium-battery cell-component flammability.

1. Overcharging

    In general, lithium-ion batteries are significantly more 
susceptible than their Ni-Cd or lead-acid counterparts to internal 
failures that can result in self-sustaining increases in temperature 
and pressure (i.e., thermal runaway). This is especially true for 
overcharging, which causes heating and destabilization of the 
components of the lithium-battery cell, which can lead to the 
formation, by plating, of highly unstable metallic lithium. The 
metallic lithium can ignite, resulting in a self-sustaining fire or 
explosion. The severity of thermal runaway due to overcharging 
increases with increased battery capacity due to the higher amount of 
electrolyte in large batteries.

2. Over-Discharging

    Discharge of some versions of the lithium-battery cell, beyond a 
certain voltage (typically 2.4 volts), can cause corrosion of the 
electrodes in 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 crewmembers as a means of checking battery status, a problem 
shared with Ni-Cd batteries.

3. Flammability of Cell Components

    Unlike Ni-Cd and lead-acid cells, some types of lithium-battery 
cells use flammable liquid electrolytes. The electrolyte can serve as a 
source of fuel for an external fire if the cell container is breached.
    The problems that lithium-battery users experience raise concerns 
about the use of these batteries in commercial aviation. The intent of 
these special conditions is to establish appropriate airworthiness 
standards for lithium-battery installations in the Boeing Model 737-
600, -700, -700C, -800, -900, and -900ER series airplanes and to 
ensure, as required by Sec. Sec.  25.601 and 25.1309, that these 
battery installations will not result in an unsafe condition.
    To address these concerns, these special conditions adopt the 
following requirements:
     Those sections of Sec.  25.1353 that are applicable to 
lithium batteries.
     The flammable-fluid fire-protection requirements of Sec.  
25.863. In the past, this rule was not applied to batteries in 
transport-category airplanes because the electrolytes in lead-acid and 
Ni-Cd batteries are not considered flammable.
     New requirements to address hazards of overcharging and 
over-discharging that are unique to rechargeable lithium-ion batteries.
     Section 25.1529, Instructions for Continued Airworthiness, 
must include maintenance requirements to ensure that batteries used as 
spares are maintained in an appropriate state of charge, and installed 
lithium batteries are sufficiently charged at appropriate intervals. 
These instructions must also describe proper repairs, if allowed, and 
battery part-number configuration control.
    In issuing these special conditions, the FAA requires that:
    (1) All characteristics of the lithium batteries and their 
installation that could affect safe operation of the Boeing Model 737-
600, -700, -700C, -800, -900, and -900ER series airplanes are 
addressed, and
    (2) Appropriate instructions for continued airworthiness, which 
include maintenance requirements, are established to ensure the 
availability of electrical power from the batteries when needed.

Applicability

    As discussed above, these special conditions are applicable to the 
Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes. Should Electronic Cable Specialists, Inc., apply at a later 
date for a supplemental type certificate to modify any other model 
included on type certificate A16WE to incorporate the same novel or 
unusual design feature, the special conditions would apply to that 
model as well.

[[Page 57627]]

Conclusion

    This action affects only certain novel or unusual design features 
on Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes. It is not a rule of general applicability and it affects 
only the applicant who 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 Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) issues the 
following special conditions as part of the type certification basis 
for Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes, as modified by Electronic Cable Specialists, Inc., to 
install an EFB system including rechargeable lithium batteries.
    In lieu of the requirements of Sec.  25.1353(c)(1) through (c)(4) 
at Amendment 25-42, Lithium-ion batteries and battery installations on 
Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes must be designed and installed as follows:
    (1) Safe lithium-ion battery-cell temperatures and pressures must 
be maintained during any charging or discharging condition, and during 
any failure of the battery-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 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 or battery-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, as determined in 
accordance with Sec.  25.1309(b).
    (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 
automatically the charging rate of the battery to prevent battery 
overheating or overcharging, and
    (i) A battery-temperature-sensing and over-temperature-warning 
system with a means to automatically disconnect 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 to 
automatically disconnect the battery from its charging source in the 
event of battery failure.
    (8) Any lithium-battery installation, the function of which 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 (and 14 CFR 26.11) must contain maintenance steps to assure 
that the lithium batteries are sufficiently charged at appropriate 
intervals specified by the battery manufacturer. The instructions for 
continued airworthiness must also contain procedures to ensure the 
integrity of lithium batteries in spares storage to prevent the 
replacement of batteries, the function of which are 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 
continued-airworthiness maintenance instructions to prevent mishandling 
of lithium batteries, which could result in a 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 
retains enough of a charge, expressed in ampere-hours, to ensure 
that the battery cells are not damaged. A battery cell may be 
damaged by reducing the battery's charge below a point where the 
battery's ability to charge and retain a full charge is reduced. 
This reduced charging and charge-retention capability 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(b) at Amendments 25-77 (-600, -700, -800), 25-91 (-
700C, -900), and 25-108 (-900ER) in the certification basis of the 
Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes. These special conditions apply only to rechargeable 
lithium batteries and their use in the dual Class 3 EFB systems and 
their installation. The requirements of Sec.  25.1353(b) at 
Amendment 25-77 (-600, -700, -800), 25-91 (-700C, -900), and 25-108 
(-900ER) remain in effect for EFB batteries and battery 
installations on Boeing Model 737-600, -700, -700C, -800, -900, and 
-900ER series airplanes that do not use rechargeable lithium-ion 
batteries.


    Issued in Renton, Washington, on September 9, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-23720 Filed 9-15-11; 8:45 am]
BILLING CODE 4910-13-P