[Federal Register Volume 81, Number 195 (Friday, October 7, 2016)]
[Rules and Regulations]
[Pages 69663-69666]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-24343]



Federal Aviation Administration

14 CFR Part 23

[Docket No. FAA-2016-9224; Special Conditions No. 23-277-SC]

Special Conditions: Beechcraft, Model A36, Bonanza Airplanes; as 
Modified by Avionics Design Services, Ltd.; Installation of 
Rechargeable Lithium Battery

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.


SUMMARY: These special conditions are issued for the Beechcraft, Model 
A36, Bonanza airplane. This airplane, as modified by Avionics Design 
Services, Ltd., will have a novel or unusual

[[Page 69664]]

design feature associated with the use of a replacement option of a 
lithium battery instead of nickel-cadmium and lead-acid rechargeable 
batteries. 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: The effective date of these special conditions is October 7, 
    We must receive your comments by November 21, 2016.

ADDRESSES: Send comments identified by docket number FAA-2016-9224 
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 of 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://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 the 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: Quentin Coon, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-112, 901 Locust, Room 301, Kansas City, MO; telephone 
(816) 329-4168; facsimile (816) 329-4090.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected aircraft. In addition, the FAA 
has determined, in accordance with 5 U.S. C. 553(b)(3)(B) and 
553(d)(3), that notice and opportunity for prior public comment hereon 
are unnecessary because the substance of these special conditions has 
been subject to the public comment process in several prior instances 
with no substantive comments received. The FAA therefore finds that 
good cause exists for making these special conditions effective upon 

         Special conditions No.               Company/airplane model
23-15-01-SC \1\........................  Kestrel Aircraft Company/Model
23-09-02SC \2\.........................  Cessna Aircraft Company/Model
                                          525C (CJ4).
23-08-05-SC \3\........................  Spectrum Aeronautical, LLC/
                                          Model 40.

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 ask 
that you send us two copies of written comments.

    \1\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/39B156C006EB842E86257EF3004BB13C?OpenDocument&Highlight=installation%20of%20rechargeable%20lithium%20battery.
    \2\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/902232309C19F0D4862575CB0045AC0D?OpenDocument&Highlight=installation%20of%20rechargeable%20lithium%20battery.
    \3\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/28E630294DCC27B986257513005968A3?OpenDocument&Highlight=installation%20of%20rechargeable%20lithium%20battery.

    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.


    On September 17, 2015, Avionics Design Services, Ltd., (Avionics) 
applied for a supplemental type certificate (STC) to install a 
rechargeable lithium battery on the Model A36 Bonanza airplane. The 
Model A36 airplane is a normal category airplane, powered by a single-
piston engine that drives an aircraft propeller, with passenger seating 
up to six (6) and a maximum takeoff weight of 3600 pounds.
    The current regulatory requirements for part 23 airplanes do not 
contain adequate requirements for the application of rechargeable 
lithium batteries in airborne applications. This type of battery 
possesses certain failure and operational characteristics with 
maintenance requirements that differ significantly from that of the 
nickel-cadmium (Ni-Cd) and lead-acid rechargeable batteries currently 
approved in other normal, utility, acrobatic, and commuter category 
airplanes. Therefore, the FAA is proposing this special condition to 
address (1) all characteristics of the rechargeable lithium batteries 
and their installation that could affect safe operation of the modified 
Model A36 airplane, and (2) appropriate Instructions for Continued 
Airworthiness (ICAW) that include maintenance requirements to ensure 
the availability of electrical power from the batteries when needed.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (CFR) 
21.101, Avionics must show that the Model A36 airplane, as changed, 
continues to meet the applicable provisions of the regulations 
incorporated by reference in Type Certificate Data Sheet No. 3A15 \4\ 
or the applicable regulations in effect on the date of application for 
the change.

    \4\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/360C62B668F4C1878625801B0069FB5F?OpenDocument.

    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 23) do not contain adequate or 
appropriate safety standards for the Model A36 airplane because of a 
novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model A36 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 Sec.  11.19, under 
Sec.  11.38 and they become part of the type certification basis under 
Sec.  21.101.
    Special conditions are initially applicable to the models for which 

[[Page 69665]]

are issued. Should the applicant apply for an STC 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.

Novel or Unusual Design Features

    The Beechcraft Model A36 airplane will incorporate the following 
novel or unusual design features:
    The installation of a rechargeable lithium battery as a main or 
engine start aircraft battery.


    The applicable part 23 airworthiness regulations governing the 
installation of batteries in general aviation airplanes, including 
Sec.  23.1353, were derived from Civil Air Regulations (CAR) 3 as part 
of the recodification that established 14 CFR part 23. The battery 
requirements, which are identified in Sec.  23.1353, were a rewording 
of the CAR requirements that did not add any substantive technical 
requirements. An increase in incidents involving battery fires and 
failures that accompanied the increased use of Ni-Cd batteries in 
aircraft resulted in rulemaking activities on the battery requirements 
for small airplanes. These regulations were incorporated into Sec.  
23.1353(f) and (g), which apply only to Ni-Cd battery installations.
    The introduction of lithium batteries into aircraft raises some 
concern about associated battery or cell monitoring systems and the 
impact to the electrical system when monitoring components fail. 
Associated battery or cell monitoring systems (e.g., temperature, state 
of charge, etc.) should be evaluated with respect the expected extremes 
in the aircraft operating environment.
    Lithium batteries typically have different electrical impedance 
characteristics than Ni-Cd or lead-acid batteries. Avionics needs to 
evaluate other components of the aircraft electrical system with 
respect to these characteristics.
    Presently, there is limited experience with use of rechargeable 
lithium batteries and rechargeable lithium battery systems in 
applications involving commercial aviation. However, other users of 
this technology, ranging from personal computers, wireless telephone 
manufacturers to the electric vehicle industry, have noted safety 
problems with rechargeable lithium batteries. These problems include 
overcharging, over-discharging, flammability of cell components, cell 
internal defects, and during exposure to extreme temperatures that are 
described in the following paragraphs.
    1. Overcharging: In general, rechargeable lithium batteries are 
significantly more susceptible than their Ni-Cd or lead-acid 
counterparts to thermal runway, which is an internal failure that can 
result in self-sustaining increases in temperature and pressure. This 
is especially true for overcharging which causes heating and 
destabilization of the components of the cell, leading to the formation 
(by plating) of highly unstable metallic lithium. The metallic lithium 
can ignite, resulting in a self-sustaining fire or explosion. Finally, 
the severity of thermal runaway due to overcharging increases with 
increasing battery capacity due to the higher amount of electrolyte in 
large batteries.
    2. Over-discharging: Discharge of some types of rechargeable 
lithium battery cells beyond the manufacturer's recommended 
specification can cause corrosion of the electrodes of the cell, 
resulting in loss of battery capacity that cannot be reversed by 
recharging. This loss of capacity may not be detected by the simple 
voltage measurements commonly available to flight crews as a means of 
checking battery status--a problem shared with Ni-Cd batteries. In 
addition, over-discharging has the potential to lead to an unsafe 
condition (creation of dendrites that could result in internal short 
circuit during the recharging cycle).
    3. Flammability of Cell Components: Unlike Ni-Cd and lead-acid 
batteries, some types of rechargeable lithium batteries use liquid 
electrolytes that are flammable. The electrolyte can serve as a source 
of fuel for an external fire, if there is a breach of the battery 
    4. Cell Internal Defects: The rechargeable lithium batteries and 
rechargeable battery systems have a history of undetected cell internal 
defects. These defects may or may not be detected during normal 
operational evaluation, test and validation. This may lead to an unsafe 
condition during in service operation.
    5. Extreme Temperatures: Exposure to an extreme temperature 
environment has the potential to create major hazards. Care must be 
taken to ensure that the lithium battery remains within the 
manufacturer's recommended specification.
    These problems experienced by users of lithium batteries raise 
concern about the use of lithium batteries in aviation. The intent of 
the proposed special condition is to establish appropriate 
airworthiness standards for lithium battery installations in the Model 
A36 airplanes and to ensure, as required by Sec. Sec.  23.1309 and 
23.601, that these battery installations are not hazardous or 


    The special conditions are applicable to the Model A36 airplane. 
Should Avionics apply at a later date for an STC to modify any other 
model included on Type Certificate No. 3A15, to incorporate the same 
novel or unusual design feature, the special conditions would apply to 
that model as well.


    This action affects only certain novel or unusual design features 
on the Model A36 airplane. 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 subject contained herein. Therefore, notice and opportunity 
for prior public comment hereon are unnecessary and the FAA finds good 
cause, in accordance with 5 U.S. Code Sec. Sec.  553(b)(3)(B) and 
553(d)(3), making these special conditions effective upon issuance. 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 23

    Aircraft, Aviation safety, Signs and symbols.


The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and 
21.101; and 14 CFR 11.38 and 11.19.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the supplemental type certification basis for Beechcraft, Model A36 
airplanes modified by Avionics Design Services, Ltd.

1. Installation of Lithium Battery

    The FAA adopts that the following special conditions be applied to 
lithium battery installations on the Model A36 airplanes in lieu of the 
requirements Sec.  23.1353(a)(b)(c)(d)(e), amendment 49.

[[Page 69666]]

    Lithium battery installations on the Model A36 airplanes must be 
designed and installed as follows:
    a. Safe cell temperatures and pressures must be maintained during 
any probable charging or discharging condition, or during any failure 
of the charging or battery monitoring system not shown to be extremely 
remote. The lithium battery installation must be designed to preclude 
explosion or fire in the event of those failures.
    b. Lithium batteries must be designed to preclude the occurrence of 
self-sustaining, uncontrolled increases in temperature or pressure.
    c. No explosive or toxic gasses emitted by any lithium battery in 
normal operation or as the result of any failure of the battery 
charging or monitoring system, or battery installation not shown to be 
extremely remote, may accumulate in hazardous quantities within the 
    d. Lithium batteries that contain flammable fluids must comply with 
the flammable fluid fire protection requirements of 14 CFR 23.863(a) 
through (d).
    e. No corrosive fluids or gases that may escape from any lithium 
battery may damage airplane structure or essential equipment.
    f. Each lithium battery installation must have provisions to 
prevent any hazardous effect on structure or essential systems that may 
be caused by the maximum amount of heat the battery can generate during 
a short circuit of the battery or of its individual cells.
    g. Lithium battery installations must have--
    (1) A system to control the charging rate of the battery 
automatically to prevent battery overheating or overcharging, or
    (2) A battery temperature sensing and over-temperature warning 
system with a means for automatically disconnecting the battery from 
its charging source in the event of an over-temperature condition or,
    (3) A battery failure sensing and warning system with a means for 
automatically disconnecting the battery from its charging source in the 
event of battery failure.
    h. Any lithium battery installation functionally required for safe 
operation of the airplane, must incorporate a monitoring and warning 
feature that will provide an indication to the appropriate flight 
crewmembers, whenever the capacity and state of charge of the batteries 
have fallen below levels considered acceptable for dispatch of the 
    i. The ICAW must contain recommended manufacturer's maintenance and 
inspection requirements to ensure that batteries, including single 
cells, meet a functionally safe level essential to the aircraft's 
continued airworthiness.
    (1) The ICAW must contain operating instructions and equipment 
limitations in an installation maintenance manual.
    (2) The ICAW must contain installation procedures and limitations 
in a maintenance manual, sufficient to ensure that cells or batteries, 
when installed according to the installation procedures, still meet 
safety functional levels essential to the aircraft's continued 
airworthiness. The limitations must identify any unique aspects of the 
    (3) The ICAW must contain corrective maintenance procedures to 
check battery capacity at manufacturer's recommended inspection 
    (4) The ICAW must contain scheduled servicing information to 
replace batteries at manufacturer's recommended replacement time.
    (5) The ICAW must contain maintenance and inspection requirements 
how to check visually for battery and charger degradation.
    j. Batteries in a rotating stock (spares) that have degraded charge 
retention capability or other damage due to prolonged storage must be 
checked at manufacturer's recommended inspection intervals.
    k. If the lithium battery application contains software and/or 
complex hardware, in accordance with AC 20-115 \5\ and AC 20-152,\6\ 
they should be developed to the standards of DO-178 for software and 
DO-254 for complex hardware.

    \5\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/E35FBC0060E2159186257BBE00719FB3?OpenDocument&Highlight=ac%2020-115b.
    \6\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/6D4AE0BF1BDE3579862570360055D119?OpenDocument&Highlight=ac%2020-152.

    Compliance with the requirements of this Special Condition must be 
shown by test or analysis, with the concurrence of the New York 
Aircraft Certification Office.

    Issued in Kansas City, Missouri on September 28, 2016.
William Schinstock,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
[FR Doc. 2016-24343 Filed 10-6-16; 8:45 am]