Airworthiness Directives; Learjet Model 45 Airplanes

[Federal Register Volume 67, Number 167 (Wednesday, August 28, 2002)]
[Rules and Regulations]
[Pages 55106-55108]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-21707]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-167-AD; Amendment 39-12866; AD 2002-17-01]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 45 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Learjet Model 45 airplanes. This action 
requires pulling the FOOT WARM circuit breaker located on the copilot's 
circuit breaker panel, and installing a collar on that circuit breaker. 
This action is necessary to prevent an electrical short circuit between 
the pilot's and copilot's foot warmers and the composite floorboards, 
which could result in outgassing of the faceply material of the 
composite floorboards, and consequent smoke in the cockpit. This action 
is intended to address the identified unsafe condition.

DATES: Effective September 12, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 12, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before October 28, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-167-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-167-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in this AD may be obtained from 
Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Wichita 
Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-
Continent Airport, Wichita, Kansas; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jose R. Flores, Aerospace Engineer, 
ACE-116W, FAA, Wichita Aircraft Certification Office, 1801 Airport 
Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone 
(316) 946-4133; fax (316) 946-4407.

SUPPLEMENTARY INFORMATION: The FAA has received reports of smoke in the 
cockpit caused by electrical short circuits between the pilot's and 
copilot's foot warmers and the composite floorboards. A short circuit 
in a foot warmer causes electrical current to flow through the metal 
heelplate of the foot warmer to the composite floorboards. Due to the 
high resistance of the composite floorboards, the circuit

[[Page 55107]]

breaker may not open, or the opening could be significantly delayed.
    After the first incident, that occurred on an older design of the 
foot warmer, the manufacturer re-designed the foot warmer to minimize 
the potential for this failure mode. After the latest incident, the re-
designed foot warmer was evaluated, and was found to have the same 
potential for an electrical short circuit. This condition, if not 
corrected, could result in outgassing of the faceply material of the 
composite floorboard, and consequent smoke in the cockpit.

Explanation of Relevant Service Information

    We have reviewed and approved Learjet Alert Service Bulletin SB 
A45-21-14, dated May 3, 2002, which describes procedures for pulling 
the FOOT WARM circuit breaker located on the copilot's circuit breaker 
panel. The alert service bulletin also describes procedures for 
installation of a collar on the foot warmer circuit breaker to prevent 
the FOOT WARM circuit breaker from being activated.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to prevent an electrical short circuit in the pilot's and 
copilot's foot warmers, which could result in outgassing of the faceply 
material of the composite floorboard, and consequent smoke in the 
flightdeck. This AD requires pulling the FOOT WARM circuit breaker 
located on the copilot's circuit breaker panel, and installing a collar 
on that circuit breaker. The actions are required to be accomplished in 
accordance with the alert service bulletin described previously.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently is developing a modification that will 
address the unsafe condition addressed by this AD. Once this 
modification is developed, approved, and available, we may consider 
additional rulemaking.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the AD is 
being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-167-AD.'' The postcard will be date stamped 
and returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect on the States, on the relationship between the national 
Government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

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


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

2002-17-01  Learjet: Amendment 39-12866. Docket 2002-NM-167-AD.

    Applicability: Model 45 airplanes, serial numbers 45-005 through 
45-213 inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent an electrical short circuit between the pilot's and 
copilot's foot

[[Page 55108]]

warmers and the composite floor boards, which could result in 
outgassing of the faceply material of the composite floorboards, and 
consequent smoke in the cockpit, accomplish the following:

Circuit Breaker Deactivation and Collar Installation

    (a) Within 25 flight hours after the effective date of this AD, 
pull the FOOT WARM circuit breaker located on the copilot's circuit 
breaker panel, and install a collar on the FOOT WARM circuit 
breaker, per Learjet Alert Service Bulletin SB A45-21-14, dated May 
3, 2002.

Alternative Methods of Compliance

    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Wichita Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Wichita ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Wichita ACO.

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (d) The actions shall be done in accordance with Learjet Alert 
Service Bulletin SB A45-21-14, dated May 3, 2002. This incorporation 
by reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-
2942. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 
100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

Effective Date

    (e) This amendment becomes effective on September 12, 2002.

    Issued in Renton, Washington, on August 20, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-21707 Filed 8-27-02; 8:45 am]
BILLING CODE 4910-13-P

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