[Federal Register Volume 75, Number 69 (Monday, April 12, 2010)]
[Rules and Regulations]
[Pages 18399-18402]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-8218]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM426; Special Conditions No. 25-404-SC]
Special Conditions: Modification to Boeing Model 737-600/-700/-
700C/-800/-900 and -900ER Series Airplanes: Rechargeable Lithium
Batteries and Rechargeable Lithium-Battery Systems
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 737-600/-
700/-700C/-800/-900 and -900ER Series airplanes (hereafter referred to
as ``Boeing 737NG''). These airplanes, as modified by the Boeing
Company, will have a novel or unusual design feature associated with
the installation of rechargeable lithium batteries and rechargeable
lithium-battery systems. 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 April 5, 2010.
We must receive your comments by May 27, 2010.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attn: Rules
Docket (ANM-113), Docket No. NM426, 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. NM426. 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) 227-1320.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and
opportunity for prior public comment on, these special conditions are
impracticable because these procedures
[[Page 18400]]
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
reasons for recommended changes, 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 may change these special conditions based on the comments
we receive.
If you want us to acknowledge receipt of your comments on these
special conditions, 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
The Boeing Company has applied for a type-design change for the
Boeing 737NG airplanes to use rechargeable lithium batteries and
rechargeable lithium-battery systems in different applications,
including the recorder independent power supply (RIPS). Lithium
batteries have 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. Large, high-
capacity, rechargeable lithium batteries and rechargeable lithium-
battery systems are a novel or unusual design feature in transport-
category airplanes. The FAA is proposing this special condition to
require that (1) all characteristics of rechargeable lithium battery
and rechargeable lithium-battery system installation, that could affect
safe operation of the Boeing 737NG, 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.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulations (14
CFR) 21.101, the Boeing Company must show that the Boeing 737NG
airplanes, as changed, continue to meet the applicable provisions of
the regulations incorporated by reference in Type Certificate No. 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 regulation incorporated by reference in
A16WE is 14 CFR 25.1353 at Amendment 25-38.
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 Company rechargeable
lithium batteries and rechargeable lithium-battery systems because of a
novel or unusual design feature, special conditions are prescribed
under the provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Boeing 737NG 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; and the FAA must issue a
finding of regulatory adequacy under SECTION 611 of Public Law 92-574,
the ``Noise Control Act of 1972.''
The FAA issues special conditions, as defined in Sec. 11.19, in
accordance with Sec. 11.38, and they become part of the type-
certification basis under Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should the applicant apply for a type-design change to
modify any other model included on the same type certificate, to
incorporate the same novel or unusual design feature, the special
conditions would also apply to the other model.
Novel or Unusual Design Features
The Boeing Company modification to Boeing 737NG airplanes will
incorporate the following novel or unusual design feature: Rechargeable
lithium batteries and rechargeable lithium-battery systems.
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 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 Sec. 25.1353(c)(5) and (c)(6),
governing nickel-cadmium battery installations on large, transport-
category airplanes.
The proposed use of rechargeable lithium batteries and rechargeable
lithium-battery systems for equipment and systems on the Boeing 737NG
have 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 rechargeable lithium batteries and rechargeable
lithium-battery systems that could affect the safety and reliability of
the Boeing 737NG rechargeable lithium batteries and rechargeable
lithium-battery system installations.
At present, commercial aviation has limited experience with the use
of rechargeable lithium batteries and rechargeable lithium-battery
systems in aviation applications. 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
cell-component flammability.
1. Overcharging
In general, rechargeable lithium batteries and rechargeable
lithium-battery systems 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
[[Page 18401]]
metallic lithium. 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 greater amount of liquid electrolytes in large batteries.
2. Over-discharging
Discharge of some types of rechargeable lithium batteries and
rechargeable lithium-battery systems 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
rechargeable lithium batteries and rechargeable lithium-battery systems
use liquid electrolytes that are flammable. Electrolytes can serve as a
source of fuel for an external fire from a breach of the battery
container.
Such problems, experienced by users of rechargeable lithium
batteries and rechargeable lithium-battery systems, raise concern about
the use of these batteries in commercial aviation. The intent of these
proposed special conditions is to establish appropriate airworthiness
standards for rechargeable lithium-battery and rechargeable lithium-
battery system installations in Boeing 737NG airplanes and to ensure,
as required by Sec. Sec. 25.1309 and 25.601, that these battery
installations are not hazardous or unreliable.
Applicability
As discussed above, these special conditions are applicable to the
Boeing Company. Should the Boeing Company apply at a later date for a
type-design change to modify any other model included on Type
Certificate No. A16WE, to incorporate the same novel or unusual design
feature, the special conditions would apply to that model as well.
Conclusion
This action affects only certain novel or unusual design features
relating to rechargeable lithium batteries and rechargeable lithium-
battery systems installed on Boeing 737NG airplanes. It is not a rule
of general applicability and affects only the applicant who applied to
the FAA for approval of these features on the airplane.
The substance of these special conditions has been subjected to the
notice and comment period in several prior instances and has been
derived without substantive change from those previously issued. It is
unlikely that prior public comment would result in a significant change
from the substance contained herein. Therefore, because a delay would
significantly affect the certification of the airplane, which is
imminent, the FAA has determined that prior public notice and comment
are unnecessary and impracticable, and good cause exists for adopting
these special conditions upon issuance. The FAA is requesting comments
to allow interested persons to submit views that may not have been
submitted in response to the prior opportunities for comment described
above.
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, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type-certification basis for Boeing 737NG airplanes modified by
Boeing Company to install rechargeable lithium-battery systems on
Boeing 737NG airplanes. These systems 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--
(i) A system to automatically control the charging rate of the
battery, to prevent battery overheating or overcharging, and,
(ii) 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,
(iii) 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 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 Sec. 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 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 lithium batteries, which could result in short-circuit or other
unintentional damage that could result in personal injury or property
damage.
[[Page 18402]]
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(b) in the certification basis of the Boeing 737NG.
These special conditions apply only to rechargeable lithium
batteries and rechargeable lithium-battery system installations. The
requirements of Sec. 25.1353(b) remains in effect for batteries and
battery installations of Boeing 737NG that do not use lithium
batteries.
Boeing must show compliance with the requirements of these special
conditions by test and/or analysis. The aircraft certification office,
or its designees, will find compliance in coordination with the FAA
Transport Standards Staff.
Issued in Renton, Washington, on April 5, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-8218 Filed 4-9-10; 8:45 am]
BILLING CODE 4910-13-P