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[Federal Register Volume 80, Number 169 (Tuesday, September 1, 2015)]
[Rules and Regulations]
[Pages 52615-52617]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-21626]

[[Page 52615]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2015-3653; Special Conditions No. 25-591-SC]

Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and 
BD-500-1A11 Series Airplanes; Installed 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 Bombardier 
Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. 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 batteries and battery systems that have 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 large transport category 
airplanes. The applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for these design features. 
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 Bombardier Aerospace on September 1, 
2015. We must receive your comments by October 1, 2015.

ADDRESSES: Send comments identified by docket number FAA-2015-3653 
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/ 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 airplanes. 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 December 10, 2009, Bombardier Aerospace applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes (hereafter collectively referred to as ``CSeries''). The 
CSeries airplanes are swept-wing monoplanes with an aluminum alloy 
fuselage, sized for 5-abreast seating. Passenger capacity is designated 
as 110 for the Model BD-500-1A10 and 125 for the Model BD-500-1A11. 
Maximum takeoff weight is 131,000 pounds for the Model BD-500-1A10 and 
144,000 pounds for the Model BD-500-1A11. The CSeries airplanes will 
use rechargeable lithium batteries and battery systems for equipment 
and systems.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Bombardier Aerospace must show that the CSeries airplanes 
meet the applicable provisions of 14 CFR part 25 as amended by 
Amendments 25-1 through 25-129.
    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 CSeries airplanes 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 type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
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 CSeries airplanes 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, and the FAA must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    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.  21.17(a)(2).

Novel or Unusual Design Features

    The CSeries will incorporate the following novel or unusual design 
feature: Installed rechargeable lithium batteries and battery systems 
that have certain failure, operational, and maintenance characteristics 
that differ

[[Page 52616]]

significantly from those of the nickel-cadmium and lead-acid 
rechargeable batteries currently approved for installation on large 
transport-category 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.

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 recodified 
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, 
with Amendments 25-41 and 25-42 respectively, the FAA added paragraphs 
(c)(5) and (c)(6) to Sec.  25.1353 governing nickel-cadmium battery 
installations on large, transport-category airplanes. On December 10, 
2007, Amendment 25-123 moved the contents of paragraph (b) in Sec.  
25.1353 to the new subpart H, resulting in the relocation of the 
regulations governing the installation of batteries in Sec.  25.1353 
from paragraph (c) to paragraph (b).
    The proposed use of rechargeable lithium batteries for equipment 
and systems 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 lithium batteries that could affect the safety and 
reliability of the lithium battery installations.
    At present, there is limited experience with the use of lithium 
batteries in applications involving commercial aviation. However, other 
users of this technology, ranging from wireless telephone manufacturers 
to the electric vehicle industry, have noted safety problems 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 these special conditions is to establish appropriate 
airworthiness standards for lithium battery installations in the 
CSeries airplanes and to ensure, as required by Sec. Sec.  25.601 and 
25. 1309, that these battery installations are not hazardous or 
unreliable.

Applicability

    As discussed above, these special conditions are applicable to the 
Models BD-500-1A10 and BD-500-1A11 series airplanes. Should Bombardier 
Aerospace apply at a later date for a change to the type certificate to 
include another model incorporating the same novel or unusual design 
feature, the special conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on two model series of airplanes. It is not a rule of general 
applicability.
    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, 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.

0
The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

0
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 Bombardier BD-500-1A10 and BD-500-1A11 
series airplanes.
    In lieu of the requirements of Title 14 Code of Federal Regulations 
(14 CFR) 25.1353(b)(1) through (b)(4) at Amendment 25.129 for 
rechargeable lithium batteries and battery systems, all installations 
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 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).

[[Page 52617]]

    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. 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 aircraft system, 
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 there is 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 25-129 in the certification basis of 
BD-500-1A10 and BD-500-1A11 series 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 25-129 remain in effect for batteries and 
battery installations on BD-500-1A10 and BD-500-1A11 series 
airplanes that do not use lithium batteries.

Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-21626 Filed 8-31-15; 8:45 am]
BILLING CODE 4910-13-P
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