[Federal Register: April 8, 2009 (Volume 74, Number 66)]
[Rules and Regulations]
[Page 15831-15833]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08ap09-1]
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Rules and Regulations
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[[Page 15831]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM401; Special Conditions No. 25-380-SC]
Special Conditions: Rosemount Aerospace Inc., Modification to
Boeing 737-600, -700, -800, and -900 Series Airplanes: 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, -800, and -900 Series airplanes. These airplanes, as modified by
Rosemount Aerospace Inc., will have a novel or unusual design feature
associated with the installation of lithium 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 March 30,
2009. We must receive your comments by May 26, 2009.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attn: Rules
Docket (ANM-113), Docket No. NM401, 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. NM401. 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 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
On October 4, 2007, Rosemount Aerospace Inc. applied for a
supplemental type certificate for the installation of a Rosemount
Aerospace Inc., 8700A1-3 Series Electronic Flight Bag (EFB) in Boeing
737-600, -700, -800, and -900 Series airplanes.
Type Certification Basis
Under the provisions of Sec. 21.101, Rosemount Aerospace Inc. must
show that the Boeing 737-600, -700, -800, and -900 Series 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 Rosemount Aerospace Inc. EFB
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 Rosemount Aerospace Inc., Boeing 737-600, -700, -800,
and -900 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; and the FAA must issue a finding of
regulatory adequacy under Sec. 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 supplemental type
certificate 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.
[[Page 15832]]
Novel or Unusual Design Features
The Rosemount Aerospace Inc. modification to Boeing 737-600, -700,
-800, and -900 Series airplanes will incorporate the following novel or
unusual design feature: a lithium battery system.
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, 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, the FAA issued 14 CFR 25.1353(c)(5) and (c)(6), respectively,
governing nickel-cadmium battery installations on large, transport-
category airplanes.
The proposed use of lithium batteries for equipment and systems on
Boeing 737-600, -700, -800, and -900 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
lithium-battery installations on Boeing 737-600, -700, -800, and -900
Series airplanes.
At present, the airplane industry has limited experience with the
use of rechargeable lithium batteries in commercial-aviation
applications. However, other users of this technology, including
wireless-telephone manufacturers and 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, 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. 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 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 batteries use flammable liquid electrolytes. The electrolyte
can serve as a source of fuel for an external fire if the battery
container is breached.
These data, recorded by users of lithium batteries, raise concerns
about the use of these batteries in commercial aviation. The intent of
the proposed special condition is to establish appropriate
airworthiness standards for lithium-battery installations in Boeing
737-600, -700, -800, and -900 Series airplanes and to ensure, as
required by 14 CFR 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
Rosemount Aerospace Inc., 8700A1-3 Series Electronic Flight Bag. Should
Rosemount Aerospace Inc. apply at a later date for a supplemental type
certificate 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
on Rosemount Aerospace Inc., 8700A1-3 Series EFBs installed on Boeing
737-600, -700, -800, and -900 Series 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.
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 Boeing 737-600, -700, -800, -900
Series airplanes modified by Rosemount Aerospace Inc. Lithium batteries
and battery installations on Boeing 737-600, -700, -800, and -900
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
14 CFR 25.863(a) through (d).
5. No corrosive fluids or gases that may escape from any lithium
battery
[[Page 15833]]
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-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
automatically control the charging rate of the battery, 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, the function of which is
required for safe operation of the airplane, must incorporate a
monitoring-and-warning feature that provides an indication to the
appropriate flight-crew members when 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 (and 26.11), must contain maintenance steps to:
a. Assure that the lithium battery is sufficiently charged at
appropriate intervals specified by the battery manufacturer.
b. Ensure the integrity 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.
The Instructions for Continued Airworthiness maintenance procedures
must contain precautions to prevent mishandling of the lithium battery,
which could result in short-circuit or other unintentional damage that,
in turn, 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 the battery's
ability to charge and retain a full charge is reduced. 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 14
CFR 25.1353(b) in the certification basis of the Boeing 737-600, -
700, -800, and -900 Series airplanes. These special conditions apply
only to lithium batteries and their installations. The requirements
of 14 CFR 25.1353(b) remain in effect for batteries and battery
installations in Boeing 737-600, -700, -800, and -900 Series
airplanes that do not use lithium batteries.
Compliance with the requirements of these special conditions must
be shown by test, or analysis by the Aircraft Certification Office, or
its designees, with the concurrence of the FAA Transport Airplane
Directorate.
Issued in Renton, Washington, on March 30, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-7907 Filed 4-7-09; 8:45 am]
BILLING CODE 4910-13-P