[Federal Register Volume 87, Number 193 (Thursday, October 6, 2022)]
[Rules and Regulations]
[Pages 60549-60551]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-21663]



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 Rules and Regulations
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  Federal Register / Vol. 87, No. 193 / Thursday, October 6, 2022 / 
Rules and Regulations  

[[Page 60549]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2022-1284; Special Conditions No. 25-834-SC]


Special Conditions: Aerospace Quality Research and Development, 
Textron Aviation Inc. Model 680A Latitude Airplane; Rechargeable 
Lithium Batteries and Battery Systems Installations

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Textron Aviation 
Inc. (Textron) Model 680A Latitude airplane, as modified by Aerospace 
Quality Research and Development (AQRD). These airplanes 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 the installation of two 
rechargeable lithium batteries and battery system that will replace two 
nickel-cadmium batteries previously installed on the airplane. 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 AQRD on October 6, 2022. Send 
comments on or before November 21, 2022.

ADDRESSES: Send comments identified by Docket No. FAA-2022-1284 using 
any of the following methods:
     Federal eRegulations Portal: Go to https://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     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.
     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.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: Except for Confidential Business Information (CBI) as 
described in the following paragraph, and other information as 
described in title 14, Code of Federal Regulations (14 CFR), Sec.  
11.35, the FAA will post all comments received without change to 
https://www.regulations.gov/, including any personal information you 
provide. The FAA will also post a report summarizing each substantive 
verbal contact received about these special conditions.
    Confidential Business Information: Confidential Business 
Information (CBI) is commercial or financial information that is both 
customarily and actually treated as private by its owner. Under the 
Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from 
public disclosure. If your comments responsive to these special 
conditions contain commercial or financial information that is 
customarily treated as private, that you actually treat as private, and 
that is relevant or responsive to these special conditions, it is 
important that you clearly designate the submitted comments as CBI. 
Please mark each page of your submission containing CBI as ``PROPIN.'' 
The FAA will treat such marked submissions as confidential under the 
FOIA, and the indicated comments will not be placed in the public 
docket of these special conditions. Send submissions containing CBI to 
Nazih Khaouly, Aircraft Systems, AIR-623, Technical Innovation Policy 
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]. Comments the FAA receives, which are not 
specifically designated as CBI, will be placed in the public docket for 
these special conditions.
    Docket: Background documents or comments received may be read at 
https://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, Aircraft Systems, AIR-
623, Technical Innovation Policy 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: The substance of these special conditions 
has been published in the Federal Register for public comment in 
several prior instances with no substantive comments received. 
Therefore, the FAA finds, pursuant to Sec.  11.38(b), that new comments 
are unlikely, and notice and comment prior to this publication are 
unnecessary.

Comments Invited

    The FAA invites 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.
    The FAA will consider all comments received by the closing date for 
comments. The FAA may change these special conditions based on the 
comments received.

Background

    On April 26, 2022, AQRD applied for a supplemental type certificate 
to remove two existing nickel-cadmium (NiCad) batteries on Textron 
Model 680A Latitude airplanes and replace the NiCad batteries with two 
Mid-Continent rechargeable lithium batteries and battery system. The 
Textron Model 680A Latitude airplane, approved under Type Certificate 
No. T00012WI, is a twin-engine transport category airplane with a 
maximum seating capacity of 11

[[Page 60550]]

(2 crew plus 9 passenger seats) and has a maximum takeoff weight of 
30,800 pounds.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR), Sec.  21.101, AQRD must show that the Textron Model 680A Latitude 
airplane, as changed, continues to meet the applicable provisions of 
the regulations listed in Type Certificate No. T00012WI 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 (e.g., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Textron Model 680A Latitude 
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 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 Textron Model 680A Latitude 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.  21.101.

Novel or Unusual Design Features

    The Textron Model 680A Latitude airplane, as modified by AQRD, will 
incorporate the following novel or unusual design feature: installation 
of two rechargeable lithium batteries and battery system to replace two 
nickel-cadmium batteries previously installed on the airplane.

Discussion

    Rechargeable lithium batteries and battery systems are considered 
to be a novel or unusual design feature in transport category 
airplanes, with respect to the requirements in 14 CFR 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.
    Special Condition 1 requires that each individual cell within a 
rechargeable lithium battery be designed to maintain safe temperatures 
and pressures. Special Condition 2 addresses these same issues but for 
the entire battery system.
    Special Condition 2 requires the batteries and battery system 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 system 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.
    Special Condition 4 clarifies that the flammable fluid fire-
protection requirements of Sec.  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 and 
battery system 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 and 
battery system 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 and 
battery systems to have ``automatic'' means 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.
    These special conditions apply to all rechargeable lithium 
batteries and battery system 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 will remain in 
effect for other battery installations on these airplanes.
    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 680A Latitude airplane. Should AQRD apply at a later date 
for a supplemental type certificate to modify any other model included 
on Type Certificate No. T00012WI 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 of airplane. It is not a rule of general applicability and 
affects only the applicant who applied to the FAA for approval of this 
feature 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

    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 680A Latitude airplanes, 
as modified by AQRD.

Rechargeable Lithium Battery and Battery System 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, each

[[Page 60551]]

rechargeable lithium battery and battery system 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 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 these special 
conditions, a battery and battery system are referred to as a 
battery.


    Issued in Kansas City, Missouri, on September 30, 2022.
Patrick R. Mullen,
Manager, Technical Innovation Policy Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2022-21663 Filed 10-5-22; 8:45 am]
BILLING CODE 4910-13-P


