[Federal Register: April 8, 2009 (Volume 74, Number 66)]
[Rules and Regulations]
[Page 15838-15840]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08ap09-3]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM395; Special Conditions No. 25-379-SC]
Special Conditions: Dassault Falcon 2000 Series Airplanes;
Aircell Airborne Satcom Equipment Consisting of a Wireless Handset and
Associated Base Station, 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 Dassault Falcon
2000 series airplanes. These airplanes, as modified by Aircell LLC,
will have a novel or unusual design feature associated with the Aircell
airborne satcom equipment (ASE) 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: May 8, 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 15, 2007, Aircell LLC, applied for a type design change to
an existing STC (ST01388WI-D), to install additional equipment on
Dassault Falcon 2000 series airplanes. This installation adds
components to the existing airplane installation to include a low power
Wi-Fi handset containing a single cell lithium polymer rechargeable
battery. The battery identified for application in this design is a low
capacity, single cell lithium polymer rechargeable battery, with a
nominal capacity of 1400mAh and a nominal voltage of 3.7V. The battery
has a weight of 26.5 grams. The battery has been Underwriters
Laboratories, Inc. (UL) tested and qualified by DO-160E in the Aircell
handset (P12857). The design is supported by a System Safety
Assessment/Functional Hazard Assessment (SSA/FHA) analysis. The Aircell
Wi-Fi handset, which is a component of the Aircell ASE, consists of a
wireless handset and associated base station (cradle and charging
unit), both with protective circuits and fuse devices which provide
multiple levels of redundant protection from hazards, such as
overcharging or discharging. The lithium battery is installed in the
handset.
A lithium 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 is issuing
these special conditions to require that (1) all characteristics of the
lithium batteries and their installations that could affect safe
operation of the Dassault Falcon 2000 are addressed, and (2)
appropriate continued airworthiness instructions, which include
maintenance requirements, are established to ensure the availability of
electrical power from the batteries when needed. 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
[[Page 15839]]
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 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 the Aircell ASE
on Dassault Falcon 2000 series aircraft 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 Dassault Falcon 2000
series aircraft, modified Aircell LLC., 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, Aircell LLC, must show that
the Dassault Falcon 2000 series airplanes, as changed, continues to
meet the applicable provisions of the regulations incorporated by
reference in Type Certificate No. Type Certificate A50NM, Revision 3,
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 Dassault Falcon 2000, is listed in Type
Certificate A50NM, Revision 3, dated September 21, 2004. In addition,
the certification basis includes certain special conditions and
exemptions that are not relevant to these special conditions. Also, if
the regulations incorporated by reference do not provide adequate
standards with respect to the change, the applicant must comply with
certain regulations in effect on the date of application for the
change.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for Dassault Aviation Falcon 2000 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 Dassault Falcon 2000 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 Aircell LLC. apply for a supplemental type
certificate to modify any other model included on Type Certificate No.
A50NM 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 Dassault Aviation Falcon 2000 series airplanes, as modified by
Aircell LLC., to include the Aircell ASE which will 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 Aircell Access system will include lithium battery
installations. The application of a rechargeable lithium battery is 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 (1) all characteristics of the
lithium battery and its installation that could affect safe operation
of the satellite communication system are addressed, and (2)
appropriate maintenance requirements are established to ensure that
electrical power is available from the batteries when it is needed.
Discussion of Comments
Notice of proposed special conditions No. 25-08-07-SC for the
Dassault Falcon 2000 series airplanes was published in the Federal
Register on November 20, 2008 (73 FR 70286). One comment was received
from Dassault Falcon Jet Corporation.
Comment: Dassault requested that an additional safety requirement
be added to the text of the special conditions as follows: ``Any
equipment/system that embodies a lithium battery shall be designed so
as to ensure that it can only be connected to its own dedicated charger
which has been designed for such equipment/system. This is especially
true when the equipment/system in question has a charger which is
external to such equipment/system. In that case, the equipment/system
must be designed in a way that it is not possible to connect it to a
charger which is used for recharging other aircraft equipment and
systems with a different battery type or brand or a different lithium
technology.''
FAA Disposition: There are many ways to design equipment/systems
that embody a lithium battery power storage system. The batteries could
be either internal or external to the equipment/system. The charging
system could be
[[Page 15840]]
built-in or external to the battery storage system. In addition to the
equipment/system, the battery and the charging system could be self-
contained and designed to comply with the special conditions. The FAA
concurs that the system must be designed to ensure that the recharging
function of the system ensures proper and safe recharging. However, the
commenter's proposal is not practical. It would be onerous to require
that no other system can be connected to the battery. The safety
concern here is mitigated by the other requirements in the special
conditions. In particular, the special conditions require that safe
charging must be ensured (see Special Condition Nos. 1, 3, 7, and 9).
Therefore, we believe the special conditions are adequate. Section
25.1301 also addresses this comment. The special conditions are issued
as proposed.
Applicability
As discussed above, these special conditions are applicable to the
Dassault Aviation 2000 series airplanes as modified by Aircell LLC.
Should Aircell LLC 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 Dassault Aviation 2000 series airplanes as modified by Aircell
LLC. 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.
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 the Dassault Aviation 2000 series
airplanes, modified by Aircell LLC. in lieu of the requirements of
Sec. 25.1353(c)(1) through (c)(4), Amendment 25-113.
Lithium batteries and battery installations on Dassault Aviation
2000 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. The Instructions for Continued
Airworthiness must also contain procedures for the maintenance 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.
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
Aircell LLC. 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 Aircell LLC.
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 March 4, 2009.
Linda Navarro,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-7899 Filed 4-7-09; 8:45 am]
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