[Federal Register Volume 83, Number 15 (Tuesday, January 23, 2018)]
[Rules and Regulations]
[Pages 3062-3064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-01102]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2018-0035; Special Conditions No. 25-714-SC]


Special Conditions: Preferred Improvements, LLC, Boeing Model 
DC3C Airplanes; Rechargeable Lithium Batteries

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for Boeing Model DC3C 
airplanes as modified by Preferred Improvements, LLC. 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 rechargeable lithium ion 
backup battery packs installed on the airplanes. The applicable 
airworthiness regulations do not contain adequate or appropriate

[[Page 3063]]

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 Preferred Improvements, LLC, on 
January 23, 2018. Send your comments by March 9, 2018.

ADDRESSES: Send comments identified by docket number FAA-2018-0035 
using any of the following methods:
     Federal eRegulations Portal: Go to http://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: 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 website, 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).
    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, Airplane & Flight Crew 
Interface Section, AIR-671, Transport Standards Branch, Policy & 
Innovation Division, Aircraft Certification Service, Federal Aviation 
Administration, 1601 Lind Avenue SW, Renton, Washington 98057-3356; 
telephone (425) 227-2432; facsimile (425) 227-1320; email 
[email protected].

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions is 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
airplanes.
    In addition, 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. The FAA, therefore, 
finds it unnecessary to delay the effective date, and finds good cause 
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 February 1, 2017, Preferred Improvements, LLC, applied for a 
supplemental type certificate to install a Saab Grintek Impi II 
tracking system on Boeing Model DC3C airplanes. The tracking system 
sends altitude and speed information to a ground station via a modem, 
which contains a rechargeable lithium ion battery.
    The Boeing Model DC3C airplane is a narrow-body transport category 
airplane powered by twin-turbine/piston wing-mounted engines. The 
airplane has a maximum takeoff weight of 26,900 pounds with seating for 
2 crewmembers and 32 passengers.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Preferred Improvements, LLC, must show that the Boeing 
Model DC3C airplanes, as changed, continue to meet the applicable 
provisions of the regulations listed in Type Certificate No. A669, 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 these airplanes, as modified by 
Preferred Improvements, LLC, 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 models for which 
they are issued. Should the applicant apply for a supplemental type 
certificate to modify any other models included on the same type 
certificates to incorporate the same novel or unusual design feature, 
these special conditions would also apply to the other models under 
Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, Boeing Model DC3C airplanes, as modified by Preferred 
Improvements, LLC, 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

    Boeing Model DC3C airplanes, as modified by Preferred Improvements, 
LLC, will incorporate the following novel or unusual design feature: 
airplane tracking system with a modem containing a rechargeable lithium 
ion battery.
    The 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.

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.

[[Page 3064]]

    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. Special Condition 2 requires 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.
    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 
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 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 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. These 
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 
Boeing Model DC3C airplanes as modified by Preferred Improvements, LLC. 
Should Preferred Improvements, LLC, apply at a later date for a 
supplemental type certificate to modify any other model included on 
Type Certificate No. A699 to incorporate the same novel or unusual 
design feature, these special conditions would apply to those models 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.

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(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 Boeing Model DC3C airplanes as 
modified by Preferred Improvements, LLC.

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, 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 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 flight 
crew if its failure affects safe operation of the airplane.
    8. If its function is required for safe operation of the airplane, 
have a monitoring and warning feature that alerts the flight crew when 
its charge state falls below acceptable levels.
    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 battery system are referred to as a battery.


    Issued in Renton, Washington, on January 17, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy & Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2018-01102 Filed 1-22-18; 8:45 am]
 BILLING CODE 4910-13-P