[Federal Register Volume 87, Number 46 (Wednesday, March 9, 2022)]
[Rules and Regulations]
[Pages 13127-13129]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-04935]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2017-1141; Special Conditions No. 25-710A-SC]


Special Conditions: Dassault Aviation Model Falcon 6X Airplanes; 
Non-Rechargeable Lithium-Ion Battery Installations

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions, amendment.

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SUMMARY: These amended special conditions are issued for non-
rechargeable lithium-ion battery installations on the Dassault Aviation 
(Dassault) Model Falcon 6X airplane. Non-rechargeable lithium-ion 
batteries are a novel or unusual design feature when compared to the 
state of technology envisioned in the airworthiness standards for 
transport-category airplanes. 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: This action is effective on Dassault on March 9, 2022.

FOR FURTHER INFORMATION CONTACT: Nazih Khaouly, AIR-623, Aircraft 
Systems Section, Technical Innovation Policy Branch, Policy and 
Innovation Division, Federal Aviation Administration, 2200 S 216th 
Street, Des Moines, Washington, 98198; telephone and fax 206-231-3171, 
email [email protected].

SUPPLEMENTARY INFORMATION:

Background

    On July 1, 2012, Dassault applied for special conditions for non-
rechargeable lithium-ion batteries installed in the Model Falcon 5X 
airplane. Special conditions were issued for that design on January 16, 
2018 (83 FR 2032). However, Dassault has decided not to release an 
airplane under the model designation Falcon 5X, instead choosing to 
change that model designation to Falcon 6X.
    In February of 2018, due to engine supplier issues, Dassault 
extended the type certificate application date for its Model Falcon 5X 
airplane under new Model Falcon 6X. This amendment to the original 
special conditions reflects the model-name change. This airplane is a 
twin-engine business jet with seating for 19 passengers and a maximum 
takeoff weight of 77,460 pounds. The Dassault Model Falcon 6X airplane 
design remains unchanged from the Model Falcon 5X in all material 
respects other than different engines.
    The FAA is issuing these special conditions for non-rechargeable 
lithium-ion battery installations on the Dassault Model Falcon 6X 
airplane. The FAA's design standards in title 14, Code of Federal 
Regulations (14 CFR) part 25 are inadequate for addressing an airplane 
with non-rechargeable lithium-ion batteries.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Dassault must show that the 
Model Falcon 6X airplane meets the applicable provisions of part 25, as 
amended by Amendments 25-1 through 25-146.
    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 Dassault Model Falcon 6X airplane 
because of a novel or unusual design feature, special conditions are 
prescribed under the provisions of Sec.  21.16.
    Special conditions are initially applicable to the airplane 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 
novel or unusual design feature, these special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Dassault Model Falcon 6X airplane 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, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17.

Novel or Unusual Design Feature

    The Dassault Model Falcon 6X airplane will incorporate the 
following novel or unusual design feature: Installation of non-
rechargeable lithium-ion batteries.
    For the purpose of these special conditions, the FAA refers to a 
battery and battery system as a battery. A battery system consists of 
the battery and any protective, monitoring, and alerting circuitry or 
hardware inside or

[[Page 13128]]

outside of the battery. It also includes vents (where necessary) and 
packaging.

Discussion

    The FAA derived the current regulations governing installation of 
batteries in transport-category airplanes from Civil Air Regulations 
(CAR) 4b.625(d) as part of the recodification of CAR 4b that 
established 14 CFR part 25 in February 1965. This recodification 
basically reworded the CAR 4b battery requirements, which are currently 
in Sec.  25.1353(b)(1) through (4). Non-rechargeable lithium-ion 
batteries are novel and unusual with respect to the state of technology 
considered when these requirements were codified. Non-rechargeable 
lithium-ion batteries introduce higher energy levels into airplane 
systems through new chemical compositions in various battery cell sizes 
and construction. Interconnection of these cells in battery packs 
introduce failure modes that require unique design considerations, such 
as provisions for thermal management.
    In January 2013, two independent events involving rechargeable 
lithium-ion batteries revealed unanticipated failure modes. A National 
Transportation Safety Board (NTSB) letter to the FAA, dated May 22, 
2014, which is available at https://www.ntsb.gov, filename A-14-032-
036.pdf, describes these events.
    On July 12, 2013, an event involving a non-rechargeable lithium-ion 
battery in an emergency-locator transmitter installation demonstrated 
unanticipated failure modes. The United Kingdom's Air Accidents 
Investigation Branch Bulletin S5/2013 describes this event. These 
events involving rechargeable and non-rechargeable lithium-ion 
batteries prompted the FAA to initiate a broad evaluation of these 
energy-storage technologies.
    On April 22, 2016, the FAA published special conditions no. 25-612-
SC, in the Federal Register (81 FR 23573), applicable to Gulfstream 
Aerospace Corporation for the Model GVI airplane. Those were the first 
special conditions the FAA issued for non-rechargeable lithium-ion 
battery installations. In that document, the FAA explained its decision 
to make those special conditions effective on April 22, 2017, one year 
after publication in the Federal Register. In those special conditions, 
the FAA stated its intention to apply non-rechargeable lithium-ion 
battery special conditions to design changes on other airplane makes 
and models applied for after this same date.
    Special condition no. 1 of these special conditions requires that 
each individual cell within a non-rechargeable lithium-ion battery be 
designed to maintain safe temperatures and pressures. Special condition 
no. 2 addresses these same issues but for the entire battery. Special 
condition no. 2 requires the battery be designed to prevent propagation 
of a thermal event, such as self-sustained, uncontrollable increases in 
temperature or pressure from one cell to adjacent cells.
    Special condition nos. 1 and 2 are intended to ensure that the non-
rechargeable lithium-ion battery and its cells are designed to 
eliminate the potential for uncontrollable failures. However, a certain 
number of failures will occur due to various factors beyond the control 
of the battery designer. Therefore, other special conditions are 
intended to protect the airplane and its occupants if failure occurs.
    Special conditions 3, 7, and 8 are self-explanatory.
    Special condition no. 4 makes it clear that the flammable-fluid 
fire-protection requirements of Sec.  25.863 apply to non-rechargeable 
lithium-ion battery installations. Section 25.863 is applicable to 
areas of the airplane that could be exposed to flammable-fluid leakage 
from airplane systems. Non-rechargeable lithium-ion batteries contain 
an electrolyte that is a flammable fluid.
    Special condition no. 5 requires that each non-rechargeable 
lithium-ion battery installation not damage surrounding structure or 
adjacent systems, equipment, or electrical wiring from corrosive fluids 
or gases that may escape in such a way as to cause a major or more 
severe failure condition.
    While special condition no. 5 addresses corrosive fluids and gases, 
special condition no. 6 addresses heat. Special condition no. 6 
requires that each non-rechargeable lithium-ion battery installation 
have provisions to prevent any hazardous effect on airplane structure 
or systems caused by the maximum amount of heat the battery 
installation can generate due to any failure of it or its individual 
cells. The means of meeting special conditions nos. 5 and 6 may be the 
same, but the requirements are independent and address different 
hazards.
    These special conditions apply to all non-rechargeable lithium-ion 
battery installations in lieu of Sec.  25.1353(b)(1) through (4) at 
Amendment 25-123. Sections 25.1353(b)(1) through (4) at Amendment 25-
123 remain in effect for other battery installations.
    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.

Discussion of Comments

    The FAA issued Final Special Conditions, Request for Comment 
Special Conditions No. 25-710-SC for the Dassault Model Falcon 5X 
airplane, which was published in the Federal Register on January 16, 
2018 (83 FR 2032). No comments were received, and the special 
conditions are adopted as proposed, with amendments.

Applicability

    These special conditions are applicable to the Dassault Model 
Falcon 6X airplane. Should Dassault apply at a later date for a change 
to the type certificate to include another model incorporating the same 
novel or unusual design feature, these special conditions would apply 
to that model as well.
    These special conditions are only applicable to design changes 
applied for after the effective date.
    These special conditions are not applicable to changes to 
previously certified non-rechargeable lithium-ion battery installations 
where the only change is either cosmetic or to relocate the 
installation to improve the safety of the airplane and occupants. 
Previously certified non-rechargeable lithium-ion battery 
installations, as used in this paragraph, are those installations 
approved for certification projects applied for on or before the 
effective date of these special conditions. A cosmetic change is a 
change in appearance only, and does not change any function or safety 
characteristic of the battery installation. These special conditions 
also are not applicable to unchanged, previously certified non-
rechargeable lithium-ion battery installations that are affected by a 
change in a manner that improves the safety of its installation. The 
FAA determined that these exclusions are in the public interest because 
the need to meet all of the special conditions might otherwise deter 
these design changes that improve safety.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model of airplane. It is not a rule of general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and record keeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

[[Page 13129]]

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 the Dassault Aviation Model Falcon 6X 
airplane.

Non-Rechargeable Lithium-Ion Battery Installations

    In lieu of Sec.  25.1353(b)(1) through (4) at Amendment 25-123, 
each non-rechargeable lithium-ion battery installation must:
    1. Be designed to maintain safe cell temperatures and pressures 
under all foreseeable operating conditions to prevent fire and 
explosion.
    2. Be designed to prevent the occurrence of self-sustaining, 
uncontrollable increases in temperature or pressure.
    3. Not emit explosive or toxic gases, either in normal operation or 
as a result of its failure, that may accumulate in hazardous quantities 
within the airplane.
    4. Meet the requirements of Sec.  25.863.
    5. Not damage surrounding structure or adjacent systems, equipment, 
or electrical wiring from corrosive fluids or gases that may escape in 
such a way as to cause a major or more severe failure condition.
    6. Have provisions to prevent any hazardous effect on airplane 
structure or systems caused by the maximum amount of heat it can 
generate due to any failure of it or its individual cells.
    7. Have a failure-sensing-and-warning system to alert the 
flightcrew if its failure affects safe operation of the airplane.
    8. Have a means for the flightcrew or maintenance personnel to 
determine the battery charge state if the battery's function is 
required for safe operation of the airplane.

    Note: A battery system consists of the battery and any 
protective, monitoring, and alerting circuitry or hardware inside or 
outside of the battery. It also includes vents (where necessary) and 
packaging. For the purpose of these special conditions, a 
``battery'' and ``battery system'' are referred to as a battery.


    Issued in Kansas City, Missouri, on March 3, 2022.
Patrick R. Mullen,
Manager, Technical Innovation Policy Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2022-04935 Filed 3-8-22; 8:45 am]
BILLING CODE 4910-13-P


