[Federal Register Volume 84, Number 196 (Wednesday, October 9, 2019)]
[Rules and Regulations]
[Pages 53995-53997]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-21794]
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Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
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Federal Register / Vol. 84 , No. 196 / Wednesday, October 9, 2019 /
Rules and Regulations
[[Page 53995]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2019-0488; Special Conditions No. 25-756-SC]
Special Conditions: Voyageur Aerotech Inc., Bombardier DHC-8-100,
DHC-8-200, DHC-8-300 and DHC-8-400 Series Airplanes; Installed
Rechargeable Lithium Batteries
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the Bombardier Model
No. DHC-8-100, DHC-8-200, DHC-8-300, and DHC-8-400 series airplanes.
These airplanes, as modified by Voyageur Aerotech Inc. (Voyageur), will
have novel or unusual design features when compared to the state of
technology envisioned in the airworthiness standards for transport
category airplanes. This design feature is a rechargeable lithium
battery pack inside the Emergency Backup Power Supply. 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 October 9, 2019.
FOR FURTHER INFORMATION CONTACT: Nazih Khaouly, Airplane and Flight
Crew Interface Section, AIR-671, Transport Standards Branch, Policy and
Innovation Division, Aircraft Certification Service, Federal Aviation
Administration, 2200 South 216th Street, Des Moines, Washington 98198;
telephone and fax 206-231-3160; email [email protected].
SUPPLEMENTARY INFORMATION:
Background
On September 10, 2018, Voyageur applied for a supplemental type
certificate for a rechargeable lithium battery pack inside the
Emergency Backup Power Supply in the Model DHC-8-100, DHC-8-200, DHC-8-
300, and DHC-8-400 series airplanes. The Bombardier Model DHC-8-100,
DHC-8-200, DHC-8-300, and DHC-8-400 series airplanes are twin engine
powered airplanes with standard seating provisions for up to 86
passengers, depending on model, and a maximum takeoff weight of between
33,000 lbs. and 65,200 lbs., depending on series model.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.101, Voyageur must show that the Model DHC-8-100, DHC-8-200,
DHC-8-300, and DHC-8-400 series airplanes, as changed, continue to meet
the applicable provisions of the regulations listed in Type Certificate
No. A13NM or the applicable regulations in effect on the date of
application for the change, except for earlier amendments as agreed
upon by the FAA.
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 Bombardier Model DHC-8-100, DHC-8-
200, DHC-8-300, and DHC-8-400 series airplanes 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 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,
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 Bombardier Model DHC-8-100, DHC-8-200, DHC-8-300, and
DHC-8-400 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, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The Bombardier Model DHC-8-100, DHC-8-200, DHC-8-300, and DHC-8-400
series airplanes will incorporate the following novel or unusual design
feature:
The installation of a rechargeable lithium battery pack inside the
Emergency Backup Power Supply. Known uses of rechargeable and non-
rechargeable lithium batteries on airplanes include:
Flightdeck and avionics systems such as displays, global
positioning systems, cockpit voice recorders, flight data recorders,
underwater-locator-beacons, navigation computers, integrated avionics
computers, satellite network/communication systems, communication
management units, and remote monitor electronic line replaceable units;
Cabin safety, entertainment and communications equipment
including emergency locator transmitters, life rafts, escape slides,
seat belt air bags, cabin management systems, Ethernet switches,
routers and media servers, wireless systems, internet/in-flight
entertainment systems, satellite televisions, remotes and handsets; and
Systems in cargo areas including door controls, sensors,
video surveillance equipment and security systems.
Discussion
Rechargeable lithium batteries are considered to be a novel or
unusual design feature in transport category airplanes, with respect to
the requirements in Sec. 25.1353. 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 transport
category airplanes. These 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 introduces failure modes that require unique design
considerations, such as provisions for thermal management.
These special conditions are substantively similar to special
conditions the FAA has released in the
[[Page 53996]]
past. The special conditions have been drafted into a plain English
format, reorganized for clarity, and provide more prescriptive
instructions than previously released special conditions.
Special Condition 1 requires that each individual cell within a
battery be designed to maintain safe temperatures and pressures.
Special Condition 2 addresses these same issues but for the entire
battery. Special Condition 2 requires that the battery be designed to
prevent propagation of a thermal event, such as self-sustained,
uncontrolled increases in temperature or pressure from one cell to
adjacent cells.
Special Conditions 1 and 2 are intended to ensure that the cells
and battery 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 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, and the FAA
does not provide further explanation for them at this time.
Special Condition 4 clarifies that the flammable-fluid fire-
protection requirements of 14 CFR 25.863 apply to rechargeable lithium
battery installations. Section 25.863 is applicable to areas of the
airplane that could be exposed to flammable fluid leakage from airplane
systems. Rechargeable lithium batteries contain electrolyte that is a
flammable fluid.
Special Condition 5 requires each rechargeable lithium battery
installation to 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. Special Condition 6 requires each rechargeable lithium
battery installation to 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. The
means of meeting special conditions 5 and 6 may be the same, but they
are independent requirements addressing different hazards. Special
Condition 5 addresses corrosive fluids and gases, whereas special
condition 6 addresses heat.
Special Condition 9 requires rechargeable lithium batteries to have
automatic means, for charge rate and disconnect, due to the fast acting
nature of lithium battery chemical reactions. Manual intervention would
not be timely or effective in mitigating the hazards associated with
these batteries.
Although these special conditions require specific functionalities
and capabilities, and address certain critical failure modes of
rechargeable lithium batteries and their installations, the applicant
must also meet the requirements of Sec. Sec. 25.1301, 25.1309, and
25.1709, when applicable, in addition to these special conditions. To
date, in-service experience has shown that rechargeable lithium battery
thermal/pressure runaway conditions are not extremely improbable.
Applicants must assume such failures could occur sometime during the
life of the battery installation when demonstrating compliance with
Sec. 25.1309.
If an applicant proposes to install a rechargeable lithium battery
in a rotor burst zone, the applicant must assess the rotor burst
induced damage to the battery to show compliance with Sec.
25.903(d)(1) in conjunction with showing compliance with the
rechargeable lithium battery special condition.
These special conditions apply to all rechargeable lithium battery
installations in lieu of Sec. 25.1353(b)(1) through (4) at amendment
25-123 or Sec. 25.1353(c)(1) through (4) at earlier amendments. Those
regulations 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 Notice of Proposed Special Conditions No. 25-19-09-
SC for the Bombardier Model No. DHC-8-100, DHC-8-200, DHC-8-300, and
DHC-8-400 series airplanes, which was published in the Federal Register
on July 22, 2019 (84 FR 35041). No comments were received, and the
special conditions are adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to the
Bombardier Model DHC-8-100, DHC-8-200, DHC-8-300, and DHC-8-400 series
airplanes. Should Voyageur apply at a later date for a supplemental
type certificate to modify any other model included on Type Certificate
No. A13NM to incorporate the same novel or unusual design feature,
these special conditions would apply to that model as well.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register. However, as the certification date for the Bombardier
Model DHC-8-100, DHC-8-200, DHC-8-300, and DHC-8-400 series airplanes
is imminent, the FAA finds that good cause exists to make these special
conditions effective upon publication.
Conclusion
This action affects only certain novel or unusual design features
on Model DHC-8-100, DHC-8-200, DHC-8-300, and DHC-8-400 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.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
Authority Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(f), 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 Bombardier Model DHC-8-100, DHC-8-200,
DHC-8-300, and DHC-8-400 series airplanes, as modified by Voyageur
Aerotech Inc.
In lieu of title 14, Code of Federal Regulations (14 CFR)
25.1353(b)(1) through (4) at amendment 25-123 or Sec. 25.1353(c)(1)
through (4) at earlier amendments, each rechargeable lithium 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, and automatically
control the charge rate of each cell to protect against adverse
operating conditions, such as cell imbalance, back charging,
overcharging, and overheating.
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
[[Page 53997]]
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 monitoring and warning feature that alerts the flightcrew
when its charge state falls below acceptable levels if its function is
required for safe operation of the airplane.
9. Have a means to automatically disconnect from its charging
source in the event of an over-temperature condition, cell failure or
battery failure.
Note: A battery system consists of the battery, battery charger
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 this special condition,
a battery and the battery system is referred to as a battery.
Issued in Des Moines, Washington, on September 27, 2019.
James Wilborn,
Acting Manager, Transport Standards Branch, Policy and Innovation
Division, Aircraft Certification Service.
[FR Doc. 2019-21794 Filed 10-8-19; 8:45 am]
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