[Federal Register Volume 74, Number 66 (Wednesday, April 8, 2009)]
[Rules and Regulations]
[Pages 15838-15840]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-7899]


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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:
    <bullet> Those provisions of Sec.  25.1353 which are applicable to 
lithium batteries.
    <bullet> 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.
    <bullet> New requirements to address the hazards of overcharging 
and over-discharging that are unique to lithium batteries.
    <bullet> 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]
BILLING CODE 4910-13-P