[Federal Register Volume 72, Number 82 (Monday, April 30, 2007)]
[Proposed Rules]
[Pages 21162-21164]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-8186]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM375 Special Conditions No. 25-07-10-SC]
Special Conditions: Boeing Model 787-8 Airplane; Lithium Ion
Battery Installation
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This notice proposes special conditions for the Boeing Model
787-8 airplane. This airplane will have novel or unusual design
features when compared to the state of technology envisioned in the
airworthiness standards for transport category airplanes. The Boeing
Model 787-8 airplanes will use high capacity lithium ion battery
technology in on-board systems. For this design feature, the applicable
airworthiness regulations do not contain adequate or appropriate safety
standards. 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. Additional special conditions will be
issued for other novel or unusual design features of the Boeing Model
787-8 airplanes.
DATES: Comments must be received on or before June 14, 2007.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Transport Airplane Directorate,
Attention: Rules Docket (ANM-113), Docket No. NM375, 1601 Lind Avenue,
SW., Renton, Washington 98057-3356; or delivered in duplicate to the
Transport Airplane Directorate at the above address. All comments must
be marked Docket No. NM375. Comments may be inspected 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 & 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:
Comments Invited
The FAA invites interested persons to participate in this
rulemaking by submitting 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 proposed special conditions. The docket is available
for public inspection 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 notice 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 the
proposed special conditions based on comments we receive.
If you want the FAA to acknowledge receipt of your comments on this
proposal, include with your comments 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 28, 2003, Boeing applied for an FAA type certificate for
its new Boeing Model 787-8 passenger airplane. The Boeing Model 787-8
airplane will be an all-new, two-engine jet transport airplane with a
two-aisle cabin. The maximum takeoff weight will be 476,000 pounds,
with a maximum passenger count of 381 passengers.
Type Certification Basis
Under provisions of 14 CFR 21.17, Boeing must show that Boeing
Model 787-8 airplanes (hereafter referred to as ``the 787'') meet the
applicable provisions of 14 CFR part 25, as amended by Amendments 25-1
through 25-117, except Sec. Sec. 25.809(a) and 25.812, which will
remain at Amendment 25-115. If the Administrator finds that the
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for the 787 because of a novel or unusual
design feature, special conditions are prescribed under provisions of
14 CFR 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the 787 must comply with the fuel vent and exhaust emission
requirements of 14 CFR part 34 and the noise certification requirements
of part 36. In addition, the FAA must issue a finding of regulatory
adequacy pursuant to section 611 of Public Law 92-574, the ``Noise
Control Act of 1972.''
Special conditions, as defined in Sec. 11.19, are issued in
accordance with Sec. 11.38 and become part of the type certification
basis in accordance with Sec. 21.17(a)(2).
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same or similar
novel or unusual design feature, the special conditions would also
apply to the other model under the provisions of Sec. 21.101.
Novel or Unusual Design Features
The 787 will incorporate a number of novel or unusual design
features. Because of rapid improvements in airplane technology, the
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for these design features. These proposed
special conditions for the 787 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 787 design includes planned use of lithium ion batteries for
the following applications:
Main and Auxiliary Power Unit (APU) Battery/Battery
Charger System
Flight Control Electronics
Emergency Lighting System
Recorder Independent Power Supply
Large, high capacity, rechargeable lithium ion 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
[[Page 21163]]
installation on large transport category airplanes. The FAA is
proposing this special condition to require that (1) All
characteristics of the lithium ion battery and its installation that
could affect safe operation of the 787 are addressed, and (2)
appropriate maintenance requirements are established to ensure the
availability of electrical power from the batteries when needed.
Background
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. This 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 14 CFR 25.1353c(5) and c(6), governing
nickel-cadmium battery installations on large transport category
airplanes.
The proposed use of lithium ion batteries for the emergency
lighting system on the 787 has prompted the FAA to review the adequacy
of these existing regulations. Our review indicates that existing
regulations do not adequately address several failure, operational, and
maintenance characteristics of lithium ion batteries that could affect
the safety and reliability of the 787's lithium ion battery
installation.
At present, there is limited experience with use of rechargeable
lithium ion batteries in applications involving commercial aviation.
However, other users of this technology, ranging from wireless
telephone manufacturing to the electric vehicle industry, have noted
safety problems with lithium ion batteries. These problems include
overcharging, over-discharging, and flammability of cell components.
1. Overcharging
In general, lithium ion batteries are significantly more
susceptible to internal failures that can result in self-sustaining
increases in temperature and pressure (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 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 from overcharging increases with increasing battery
capacity, because of the higher amount of electrolytes in large
batteries.
2. Over-Discharging
Discharge of some types of lithium ion 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. This is a problem shared with nickel-cadmium
batteries.
3. Flammability of Cell Components
Unlike nickel-cadmium and lead-acid batteries, some types of
lithium ion batteries use liquid electrolytes that are flammable. The
electrolytes 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 ion batteries raise
concern about use of these batteries in commercial aviation. The intent
of these proposed special conditions is to establish appropriate
airworthiness standards for lithium ion battery installations in the
787 and to ensure, as required by 14 CFR 25.601, that these battery
installations are not hazardous or unreliable. To address these
concerns, these proposed special conditions adopt the following
requirements:
Those sections of 14 CFR 25.1353 that are applicable to
lithium ion batteries.
The flammable fluid fire protection requirements of 14 CFR
25.863. In the past, this rule 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 ion batteries.
New maintenance requirements to ensure that batteries used
as spares are maintained in an appropriate state of charge.
These proposed special conditions are similar to special conditions
adopted for the Airbus A380 (71 FR 74755); December 13, 2006).
Applicability
As discussed above, these proposed special conditions are
applicable to the 787. Should Boeing apply at a later date for a change
to the type certificate to include another model incorporating the same
novel or unusual design features, these proposed special conditions
would apply to that model as well under the provisions of Sec. 21.101.
Conclusion
This action would affect only certain novel or unusual design
features of the 787. It is not a rule of general applicability, and it
would affect only the applicant that 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 Administrator of the Federal Aviation
Administration (FAA) proposes the following special conditions as part
of the type certification basis for the Boeing Model 787-8 airplane.
In lieu of the requirements of 14 CFR 25.1353(c)(1) through
(c)(4), the following special conditions apply. Lithium ion
batteries on the Boeing Model 787-8 airplane 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 ion battery installation must
preclude explosion in the event of those failures.
(2) Design of the lithium ion batteries must preclude the
occurrence of self-sustaining, uncontrolled increases in temperature
or pressure.
(3) No explosive or toxic gases emitted by any lithium ion
battery in normal operation, or as the result of any failure of the
battery charging system, monitoring system, or battery installation
not shown to be extremely remote, may accumulate in hazardous
quantities within the airplane.
(4) Installations of lithium ion 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 ion 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 14 CFR 25.1309(b) and applicable regulatory
guidance.
[[Page 21164]]
(6) Each lithium ion 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 ion battery installations must have a system to
control the charging rate of the battery automatically, so as to
prevent battery overheating or overcharging, and,
(i) 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,
(ii) 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 ion 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 14
CFR 25.1529 must contain maintenance requirements for measurements
of battery capacity at appropriate intervals to ensure that
batteries whose function is required for safe operation of the
airplane will perform their intended function as long as the battery
is installed in the airplane. The Instructions for Continued
Airworthiness must also contain procedures for the maintenance of
lithium ion 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.
Note: These special conditions are not intended to replace 14
CFR 25.1353(c) in the certification basis of the Boeing 787-8
airplane. These special conditions apply only to lithium ion
batteries and their installations. The requirements of 14 CFR
25.1353(c) remain in effect for batteries and battery installations
of the Boeing 787-8 airplane that do not use lithium ion batteries.
Issued in Renton, Washington, on April 23, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-8186 Filed 4-27-07; 8:45 am]
BILLING CODE 4910-13-P