[Federal Register Volume 82, Number 51 (Friday, March 17, 2017)]
[Rules and Regulations]
[Pages 14119-14122]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-05334]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2016-9401; Special Conditions No. 25-651-SC]


Special Conditions: Avionics Design Services Ltd., Textron Model 
550/S550/560/560XL Airplanes; Rechargeable Lithium Batteries and 
Battery Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Textron Model 550/
S550/560/560XL airplanes. These airplanes, as modified by Avionics 
Design Services Ltd., will have a novel or unusual design feature when 
compared to the state of technology envisioned in the airworthiness 
standards for transport-category airplanes. This design feature is 
rechargeable lithium batteries and battery systems installed in the 
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 Textron on March 17, 2017. We must 
receive your comments by May 1, 2017.

ADDRESSES: Send comments identified by docket number FAA-2016-9401 
using any of the following methods:
    [squ] Federal eRegulations Portal: Go to http://www.regulations.gov/and follow

[[Page 14120]]

the online instructions for sending your comments electronically.
    [squ] Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC, 20590-0001.
    [squ] Hand Delivery or Courier: Take comments to Docket Operations 
in Room W12-140 of the West Building Ground Floor at 1200 New Jersey 
Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays.
    [squ] Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov/, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov/ at any time. Follow the online instructions 
for accessing the docket or go to Docket Operations in Room W12-140 of 
the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Nazih Khaouly, FAA, Airplane and 
Flightcrew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone 425-227-2432; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: 
    The substance of these special conditions has been subject to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, because a delay would 
significantly affect the certification of the airplane, the FAA has 
determined that prior public notice and comment are unnecessary and 
impracticable, and good cause exists for making these special 
conditions effective upon publication in the Federal Register.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending 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 will consider all comments we receive by the closing date for 
comments. We may change these special conditions based on the comments 
we receive.

Background

    On July 9, 2015, Avionics Design Services Ltd. applied for a 
supplemental type certificate for rechargeable lithium batteries and 
battery systems installed in Textron Model 550/S550/560/560XL 
airplanes. These airplanes are twin-engine, transport-category business 
jets with a maximum capacity of 8 (Models 550 and 560) or 9 (Models 
S550 and 560XL) passengers, and maximum takeoff weights of 15,100 lbs. 
(Models 550 and S550), 16,300 lbs. (Model 560), and 20,200 lbs. (Model 
560XL).

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.101, Avionics Design Services Ltd. must show that the Textron 
Model 550/S550/560/560XL airplanes, as changed, continue to meet the 
applicable provisions of the regulations listed in Type Certificate No. 
A22CE, 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 Textron Model 550/S550/560/560XL 
airplanes, as modified by Avionics Design Services Ltd., 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 Model 550/S550/560/560XL airplanes, as modified by 
Avionics Design Services Ltd., 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 Textron Model 550/S550/560/560XL airplanes, as modified by 
Avionics Design Services Ltd., will incorporate the following novel or 
unusual design feature:
    Installed rechargeable lithium batteries and battery systems.
    Rechargeable lithium 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 installation on 
transport-category airplanes.

Discussion

    Rechargeable lithium batteries are novel and unusual with respect 
to the state of technology considered when these requirements were 
codified. 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.
    Recent events involving rechargeable and non-rechargeable lithium 
batteries prompted the FAA to initiate a broad evaluation of these 
energy-storage technologies. In January 2013, two independent events 
involving rechargeable lithium-ion batteries demonstrated unanticipated 
failure modes. These events are described in a National Transportation 
Safety Board letter to the FAA, dated May 22, 2014, which is available 
at: http://www.ntsb.gov/doclib/recletters/2014/A-14-032-036.pdf.
    On July 12, 2013, an event involving a non-rechargeable lithium 
battery in an emergency-locator transmitter installation demonstrated 
unanticipated failure modes. This event is described in Air Accident 
Investigations Branch Bulletin S5/2013, available at: http://www.aaib.gov.uk/cms_resources.cfm?file=/S5-2013%20ET-AOP.pdf.

[[Page 14121]]

    Some other known uses of rechargeable and non-rechargeable lithium 
batteries on airplanes include:
    [squ] Flight deck 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 
(LRU);
    [squ] Cabin safety, entertainment and communications equipment 
including life rafts, escape slides, seatbelt air bags, cabin-
management systems, Ethernet switches, routers and media servers, 
wireless systems, internet and in-flight entertainment systems, 
satellite televisions, and remote controls and handsets; and,
    [squ] Systems in cargo areas including door controls, sensors, 
video surveillance equipment and security systems.
    Some known potential hazards and failure modes associated with 
rechargeable lithium batteries are:
    [squ] Internal failures. In general, these 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. The 
metallic lithium can ignite, resulting in a self-sustaining fire or 
explosion.
    [squ] Fast or imbalanced discharging. Fast discharging, or an 
imbalanced discharge of one cell of a multi-cell battery, may create an 
overheating condition that results in an uncontrollable venting 
condition which, in turn, leads to a thermal event or an explosion.
    [squ] Flammability. Unlike nickel-cadmium and lead-acid batteries, 
these batteries use higher energy and current in an electrochemical 
system that can be configured to maximize energy storage of lithium, 
and use liquid electrolytes that can be extremely flammable. The 
electrolyte, as well as the electrodes, can serve as a source of fuel 
for an external fire if the battery casing is breached.
    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.

Applicability

    As discussed above, these special conditions are applicable to the 
Textron Model 550/S550/560/560XL airplanes as modified by Avionics 
Design Services Ltd. Should Avionics Design Services Ltd. apply at a 
later date for a supplemental type certificate to modify any other 
model included on Type Certificate No. A22CE to incorporate the same 
novel or unusual design feature, these special conditions would apply 
to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model series of 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.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, because a delay would 
significantly affect the certification of the airplane, the FAA has 
determined that prior public notice and comment are unnecessary and 
impracticable, and good cause exists for adopting these special 
conditions upon publication in the Federal Register. The FAA is 
requesting comments to allow interested persons to submit views that 
may not have been submitted in response to the prior opportunities for 
comment described above.

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 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 Textron Model 550/S550/560/560XL 
airplanes modified by Avionics Design Services Ltd.
    Each rechargeable lithium battery installation must:
    1. Be designed so that safe cell temperatures and pressures are 
maintained under all foreseeable operating conditions to preclude fire 
and explosion.
    2. Be designed to preclude the occurrence of self-sustaining, 
uncontrolled increases in temperature or pressure.
    3. Not emit explosive or toxic gases in normal operation, or as a 
result of its failure, that may accumulate in hazardous quantities 
within the airplane.
    4. Meet the requirements of Title 14, Code of Federal Regulations 
25.863.
    5. Not damage surrounding structure or adjacent systems, equipment, 
or electrical wiring from corrosive fluids or gases that may escape.
    6. Have provisions to prevent any hazardous effect on airplane 
structure or systems caused by the maximum amount of heat the 
installation can generate due to any failure of it or its individual 
cells.
    7. Be capable of automatically controlling the charge rate of each 
cell to prevent cell imbalance, back charging, overcharging, 
overheating, and uncontrollable temperature and pressure.
    8. Have a means to be automatically disconnected from its charging 
source in the event of an over-temperature condition, cell failure, or 
battery failure.
    9. Have a failure sensing and warning system to alert the 
flightcrew if the installation's failure affects safe operation of the 
airplane.
    10. If its function is required for safe operation of the airplane, 
the installment must have a monitoring and warning feature that alerts 
the flightcrew when its charge state falls below acceptable levels.

    Note 1: 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 these special 
conditions, a battery and battery system are referred to as a 
battery.


    Note 2: These special conditions apply to all rechargeable 
lithium battery installations in lieu of Title 14, Code of Federal 
Regulations 25.1353(c)(1) through (c)(4) at Amendment 25-42. Section 
25.1353(c)(1) through (c)(4) at Amendment 25-42 remains in effect 
for other battery installations.


    Note 3: 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. The FAA includes special condition 4 to make it 
clear to applicants that the flammable-fluid fire-protection 
requirements of Sec.  25.863 apply to rechargeable lithium battery 
installations.


    Note 4: Special conditions 7 and 8 require 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.



[[Page 14122]]


    Issued in Renton, Washington, on February 23, 2017.
Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. 2017-05334 Filed 3-16-17; 8:45 am]
 BILLING CODE 4910-13-P