
[Federal Register Volume 79, Number 194 (Tuesday, October 7, 2014)]
[Rules and Regulations]
[Pages 60319-60322]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-23887]



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 Rules and Regulations
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  Federal Register / Vol. 79, No. 194 / Tuesday, October 7, 2014 / 
Rules and Regulations  

[[Page 60319]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2014-0706; Special Conditions No. 25-568-SC]


Special Conditions: Hawker Beechcraft, Model 400A Airplane, as 
Modified by Nextant Aerospace; Installed Rechargeable Lithium Batteries 
and Battery Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special condition; request for comments.

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SUMMARY: These special conditions are issued for the Hawker Beechcraft 
Model No. 400A airplane as modified by Nextant Aerospace. This 
modification will have a novel or unusual design feature associated 
with an installed emergency power supply and standby attitude module 
that use rechargeable lithium batteries and battery systems. 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, 
2014. We must receive your comments by November 21, 2014.

ADDRESSES: Send comments identified by docket number FAA-2014-0706 
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 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: Nazih Khaouly, FAA, Airplane and 
Flight Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone 425-227-2432; facsimile 425-227-1149.

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 
aircraft. In addition, 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 
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 November 29, 2012, Nextant Aerospace applied for an amendment to 
supplemental type certificate (STC) ST10959SC to replace the existing 
nickel-cadmium standby power supplies with new rechargeable lithium 
battery emergency power supplies and to install a module that uses a 
rechargeable lithium battery for emergency power back-up on the Hawker 
Beechcraft Model 400A. The Model 400A is a mid-size, nine (9) passenger 
maximum business jet powered by two turbo fan engines.
    The amendment to STC ST10959SC, Rockwell Collins Proline 21 
Instrument Display System, includes the installation of Mid-Continent 
Instrument Co. MD302 Standby Instrument and TS835 Emergency Power 
Supplies. It also includes the installation of a Midcontinent MD302 
Standby Attitude Module for emergency power back-up, all of which use 
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. Because of rapid improvements in airplane 
technology, the applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for this design feature.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Nextant Aerospace must show 
that the Model 400A, as changed,

[[Page 60320]]

continues to meet the applicable provisions of the regulations 
incorporated by reference in STC ST10959SC or the applicable 
regulations in effect on the date of application for the change. The 
regulations incorporated by reference in the STC are commonly referred 
to as the ``original type certification basis.'' The regulations 
incorporated by reference in STC ST10959SC are as follows:
    The certification basis is 14 CFR part 25 effective February 1, 
1965, as amended by 25-1 through 25-40, plus Sec. Sec.  25.1335, 
25.1351(d), 25.1353(c)(5), and 25.1447 at Amendment 25-41; Sec. Sec.  
25.29, 25.255, and 25.1353(c)(6) at Amendment 25-42; Sec. Sec.  
25.361(b) and 25.1329(h) at Amendment 25-46; 14 CFR part 36, effective 
December 1, 1969, as amended by 36-1 through 36-17; SFAR 27 effective 
February 1, 1974, as amended by 27-1 through 27-5; and Special 
Conditions No. 25-ANM-32 dated February 22, 1990, High Altitude 
Operation, and Special Conditions No. 25-ANM-33 dated June 18, 1990, 
Lightning and Radio Frequency Energy Protection.
    In addition, if the regulations incorporated by reference do not 
provide adequate standards regarding the change, the applicant must 
comply with certain regulations in effect on the date of application 
for the change. The FAA has determined that the Model 400A, as modified 
by STC ST10959SC, must also comply with the following section of part 
25 as amended by Amendment 25-1 through 25-123: Sec.  25.1353.
    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 Hawker Beechcraft Model 400A 
because of a novel or unusual design feature, special conditions are 
prescribed under the provisions of 14 CFR 21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the applicant apply for a STC to modify any 
other model included on the same type certificate to incorporate the 
same novel or unusual design feature, the special conditions would also 
apply to the other model.
    In addition to the applicable airworthiness regulations and special 
conditions, the Hawker Beechcraft Model 400A, as modified by STC 
ST10959SC, 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 14 CFR 21.101.

Novel or Unusual Design Features

    The Hawker Beechcraft Model 400A will incorporate the following 
novel or unusual design features: A Mid-Continent TS835 Emergency Power 
Supply and MD302 Standby Attitude Module that use a rechargeable 
lithium batteries and battery systems. Rechargeable lithium batteries 
are a novel or unusual design feature in transport category airplanes 
for which the applicable airworthiness regulations do not contain 
adequate or appropriate safety standards. 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

    The current regulations governing installation of batteries in 
large transport-category airplanes were derived from Civil Air 
Regulations (CAR) part 4b.625(d) as part of the re-codification of CAR 
4b that established 14 CFR part 25 in February 1965. The new battery 
requirements, Sec.  25.1353(c)(1) through (c)(4), basically reworded 
the CAR requirements.
    Increased use of nickel-cadmium batteries in small airplanes 
resulted in increased incidents of battery fires and failures that led 
to additional rulemaking affecting large transport category airplanes 
as well as small airplanes. On September 1, 1977, and March 1, 1978, 
the FAA issued Sec.  25.1353(c)(5) and (c)(6), respectively, governing 
nickel-cadmium battery installations on large transport-category 
airplanes. At Amendment 25-123, effective December 10, 2007, the FAA 
issued a revised Sec.  25.1353, which moved the battery requirements to 
Sec.  25.1353(b)(1) through (b)(6).
    The proposed use of rechargeable lithium batteries for equipment 
and systems on the Model 400A, modified by STC ST10959SC prompted the 
FAA to review the adequacy of these existing regulations. Our review 
indicates that the existing regulations do not adequately address 
several failure, operational, and maintenance characteristics of 
rechargeable lithium batteries that could affect the safety of the 
airplane and its passengers and crew.
    At present, commercial aviation has limited experience with use of 
rechargeable lithium batteries and battery systems in applications 
involving commercial aviation. However, other users of this technology, 
ranging from wireless telephone manufacturers to the electric-vehicle 
industry, have noted potential hazards with rechargeable lithium 
batteries. These problems include overcharging, over-discharging, and 
flammability of cell components.

1. Overcharging

    In general, lithium 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. This condition 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 lithium battery cells beyond a certain 
voltage (typically 2.4 volts), 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 flightcrews as a means of 
checking battery status--a problem shared with nickel-cadmium 
batteries.

3. Flammability of Cell Components

    Unlike nickel-cadmium and lead-acid batteries, some types of 
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 container.
    These problems experienced by users of lithium batteries raise 
concern about the use of these batteries in commercial aviation. The 
intent of the special conditions is to establish appropriate 
airworthiness standards for lithium battery installations in the Hawker 
Beechcraft 400A and to ensure, as required by Sec. Sec.  25.1309 and 
25.601, that these batteries are not hazardous or unreliable.

Applicability

    As discussed above, these special conditions are applicable to STC 
ST10959SC, which modifies the Hawker Beechcraft Model 400A airplane. 
Should Nextant Aerospace apply at a

[[Page 60321]]

later date to amend this STC to incorporate the same novel or unusual 
design feature, the special conditions would apply to that STC as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one airplane model. 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 date for the modification 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 Hawker Beechcraft Model 400A airplanes 
modified by Nextant Aerospace.
Installed Rechargeable Lithium Batteries and Battery Systems
    These special conditions require that (1) All characteristics of 
the rechargeable lithium batteries and battery installation, that could 
affect safe operation of the Hawker Beechcraft 400A airplanes, are 
addressed; and (2) appropriate Instructions for Continued 
Airworthiness, which include maintenance requirements, are established 
to ensure the availability of electrical power, when needed, from the 
batteries.
    In lieu of the requirements of Title 14, Code of Federal 
Regulations (14 CFR) 25.1353(b)(1) through (b)(4) at Amendment 25-123, 
all rechargeable lithium batteries and battery installations on Hawker 
Beechcraft 400A airplanes modified by ST10959SC must be designed and 
installed as follows:
    1. Safe cell temperatures and pressures must be maintained during 
any foreseeable charging or discharging condition and during any 
failure of the charging or battery monitoring system not shown to be 
extremely remote. The rechargeable lithium battery installation must 
preclude explosion in the event of those failures.
    2. Design of the rechargeable lithium batteries and battery systems 
must preclude the occurrence of self-sustaining, uncontrolled increases 
in temperature or pressure.
    3. No explosive or toxic gases emitted by any rechargeable lithium 
battery in normal operation, or as the result of any failure of the 
battery charging system, monitoring system, or battery installation 
which is not shown to be extremely remote, may accumulate in hazardous 
quantities within the airplane.
    4. Installations of rechargeable lithium batteries must meet the 
requirements of Sec.  25.863(a) through (d).
    5. No corrosive fluids or gases that may escape from any 
rechargeable lithium battery may damage surrounding structure or any 
adjacent systems, equipment, or electrical wiring of the airplane in 
such a way as to cause a major or more severe failure condition, in 
accordance with Sec.  25.1309(b) and applicable regulatory guidance.
    6. Each rechargeable lithium battery installation must have 
provisions to prevent any hazardous effect on structure or essential 
systems caused by the maximum amount of heat the battery can generate 
during a short circuit of the battery or of its individual cells.
    7. Rechargeable lithium battery installations must have a system to 
control the charging rate of the battery automatically, so as to 
prevent battery overheating or overcharging, and,
    a. 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,
    b. 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.
    8. Any rechargeable lithium battery installation, the function of 
which is 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 state-of-charge of the 
batteries has fallen below levels considered acceptable for dispatch of 
the airplane.
    9. The Instructions for Continued Airworthiness required by Sec.  
25.1529 must contain maintenance requirements to assure that the 
battery is sufficiently charged at appropriate intervals specified by 
the battery manufacturer and the equipment manufacturer that contain 
the rechargeable lithium battery or rechargeable lithium battery 
system. This is required to ensure that lithium rechargeable batteries 
and lithium rechargeable battery systems will not degrade below 
specified ampere-hour levels sufficient to power the airplane systems 
for intended applications. The Instructions for Continued Airworthiness 
must also contain procedures for the maintenance of batteries in spares 
storage to prevent the replacement of batteries with batteries that 
have experienced degraded charge retention ability or other damage due 
to prolonged storage at a low state of charge. Replacement batteries 
must be of the same manufacturer and part number as approved by the 
FAA. Precautions should be included in the Instructions for Continued 
Airworthiness maintenance instructions to prevent mishandling of the 
rechargeable lithium battery and rechargeable lithium battery systems, 
which could result in short-circuit or other unintentional impact 
damage caused by dropping or other destructive means that could result 
in personal injury or property damage.

    Note 1:  The term ``sufficiently charged'' means that the 
battery will retain enough of a charge, expressed in ampere-hours, 
to ensure that the battery cells will not be damaged. A battery cell 
may be damaged by lowering the charge below a point where the 
battery experiences a reduction in the ability to charge and retain 
a full charge. This reduction would be greater than the reduction 
that may result from normal operational degradation.


    Note 2: These special conditions are not intended to replace 
Sec.  25.1353(b) at Amendment 25-123 in the certification basis of 
airplane Hawker Beechcraft 400A airplanes. These special conditions 
apply only to rechargeable lithium batteries and lithium battery 
systems and their installations. The requirements of Sec.  
25.1353(b) at Amendment 25-123 remain in effect for batteries and 
battery installations on Hawker Beechcraft 400A airplanes that do 
not use lithium batteries.



[[Page 60322]]


     Issued in Renton, Washington, on September 9, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-23887 Filed 10-6-14; 8:45 am]
BILLING CODE 4910-13-P


