Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes

[Federal Register Volume 74, Number 31 (Wednesday, February 18, 2009)]
[Rules and Regulations]
[Pages 7554-7557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-3023]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0054; Directorate Identifier 2008-NM-222-AD; 
Amendment 39-15802; AD 2009-03-01]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 55, 55B, and 55C 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Learjet Model 55, 55B, and 55C airplanes. This AD requires inspecting 
the installation of the forward light

[[Page 7555]]

assembly in the aft lavatory to determine the location of the terminal 
connector; inspecting for damage of the light assembly terminals, 
wires, and oxygen lines; inspecting to determine if the cable nipple is 
installed over the light assembly terminal; and doing corrective 
actions if necessary. This AD also requires installing a clamp to the 
forward side of the frame to maintain a positive distance between the 
light assembly and oxygen line. This AD results from a report of a 
cabin fire in the left-hand upper cabin fuselage above the aft cabin 
window at frame 23. We are issuing this AD to detect and correct 
improper installation of the lavatory light assembly, which could 
result in contact between the electrical terminals of the light 
assembly and an adjacent oxygen supply line, and consequent short 
circuit or fire hazard.

DATES: This AD is effective March 5, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 5, 
2009.
    We must receive comments on this AD by April 20, 2009.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
    <bullet> Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Learjet, 
Inc., One Learjet Way, Wichita, Kansas 67209-2942; telephone 316-946-
2000; fax 316-946-2220; e-mail [email protected]; Internet 
http://www.bombardier.com.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Daniel Hilton, Aerospace Engineer, 
Electrical Systems and Avionics Branch, ACE-119W, FAA, Wichita Aircraft 
Certification Office, 1801 Airport Road, Room 100, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone (316) 946-4173; fax (316) 
946-4107.

SUPPLEMENTARY INFORMATION:

Discussion

    We received a report of a cabin fire in the left-hand upper cabin 
fuselage above the aft cabin window at frame 23 on a Learjet Model 55 
airplane. If installed incorrectly, the power lead terminals of the 
lavatory light assembly have the potential to chafe against the oxygen 
line, causing deterioration of the insulation on the light assembly 
wiring. This condition, if not corrected, could result in contact 
between the electrical terminals of the light assembly and an adjacent 
oxygen supply line, and consequent short circuit or fire hazard.

Relevant Service Information

    We reviewed Bombardier Alert Service Bulletin A55-25-7, dated 
December 17, 2008. The alert service bulletin describes procedures for 
an inspection of the installation of the forward light assembly in the 
aft lavatory to determine the location of the terminal connector (as 
shown in Figure 1, detail A of the alert service bulletin); an 
inspection for damage of the light assembly terminals, wires, and 
oxygen line; an inspection to determine if the cable nipple is 
installed over the light assembly terminal; and corrective actions if 
necessary. The corrective actions include turning the light assembly to 
locate the terminal connector in the forward position; replacing 
damaged light assembly terminals, wires, and oxygen line; and 
installing a new cable nipple. The alert service bulletin also 
describes procedures for installing a clamp to the forward side of the 
frame to maintain a positive distance between the light assembly and 
oxygen line.

FAA's Determination and Requirements of This AD

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the(se) same type 
design(s). This AD requires accomplishing the actions specified in the 
service information described previously, except as discussed under 
``Differences Between the AD and the Service Information.''

Differences Between the AD and the Service Information

    Operators should note that, although the Accomplishment 
Instructions of the Bombardier Alert Service Bulletin A55-25-7, dated 
December 17, 2008, describes procedures for submitting information to 
the manufacturer, this AD does not require that action.
    Bombardier Alert Service Bulletin A55-25-7, dated December 17, 
2008, refers only to doing ``inspections.'' We have determined that the 
procedures in the alert service bulletin should be described as 
``general visual inspections.'' Note 1 has been included in this AD to 
define this type of inspection.

FAA's Justification and Determination of the Effective Date

    This condition has the potential to compromise the integrity of the 
oxygen line due to the chafing between the light assembly terminals and 
oxygen line and has the potential to become an oxygen-fueled ignition 
source. Because of our requirement to promote safe flight of civil 
aircraft and thus the critical need to ensure the risk of fire is 
mitigated by proper installation of the forward light assembly in the 
aft lavatory and proper positive distance maintained between the oxygen 
line and light assembly, and the short compliance time involved with 
this action, this AD must be issued immediately.
    Because an unsafe condition exists that requires the immediate 
adoption of this AD, we find 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

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2009-0054; Directorate Identifier 2008-NM-222-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
AD. We will consider all comments received by the closing date and may 
amend this AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any

[[Page 7556]]

personal information you provide. We will also post a report 
summarizing each substantive verbal contact we receive about this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD 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.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979), and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2009-03-01 Learjet: Amendment 39-15802. Docket No. FAA-2009-0054; 
Directorate Identifier 2008-NM-222-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective March 5, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Learjet Model 55, 55B, and 55C airplanes, 
certificated in any category; serial numbers 002 through 147 
inclusive.

Subject

    (d) Air Transport Association (ATA) of America Code 25: 
Equipment/Furnishings.

Unsafe Condition

    (e) This AD results from a report of a cabin fire in the left-
hand upper cabin fuselage above the aft cabin window at frame 23. We 
are issuing this AD to detect and correct improper installation of 
the lavatory light assembly, which could result in contact between 
the electrical terminals of the light assembly and an adjacent 
oxygen supply line, and consequent short circuit or fire hazard.

Compliance

    (f) Comply with this AD within the compliance times specified, 
unless already done.

Inspections, Corrective Actions, and Installation

    (g) Within 30 days or 25 flight hours after the effective date 
of this AD, whichever occurs first, do the actions specified in 
paragraphs (g)(1) and (g)(2) of this AD. Do the actions in 
accordance with the Accomplishment Instructions of Bombardier Alert 
Service Bulletin A55-25-7, dated December 17, 2008.
    (1) Do a general visual inspection of the installation of the 
forward light assembly in the aft lavatory to determine the location 
of the terminal connector; do a general visual inspection for damage 
of the light assembly terminals, wires, and oxygen lines; do a 
general visual inspection to determine if the cable nipple is 
installed over the light assembly terminal; and do all applicable 
corrective actions. Do all applicable corrective actions before 
further flight.

    Note 1: For the purposes of this AD, a general visual inspection 
is: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
ensure visual access to all surfaces in the inspection area. This 
level of inspection is made under normally available lighting 
conditions such as daylight, hangar lighting, flashlight, or 
droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''

    (2) Install a clamp and hardware to the forward side of the 
frame to maintain the distance specified in Bombardier Alert Service 
Bulletin A55-25-7, dated December 17, 2008, between the light 
assembly and oxygen line.

No Reporting

    (h) Although Bombardier Alert Service Bulletin A55-25-7, dated 
December 17, 2008, specifies to submit certain information to the 
manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Wichita Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. Send information to ATTN: 
Daniel Hilton, Aerospace Engineer, Electrical Systems and Avionics 
Branch, ACE-119W, FAA, Wichita Aircraft Certification Office, 1801 
Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 
67209; telephone (316) 946-4173; fax (316) 946-4107.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office 
(FSDO). The AMOC approval letter must specifically reference this 
AD.

Material Incorporated by Reference

    (j) You must use Bombardier Alert Service Bulletin A55-25-7, 
dated December 17, 2008, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942; 
telephone 316-946-2000; fax 316-946-2220; e-mail 
[email protected]; Internet http://www.bombardier.com.
    (3) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at 
the FAA, call 425-227-1221 or 425-227-1152.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go

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to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on January 21, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-3023 Filed 2-17-09; 8:45 am]
BILLING CODE 4910-13-P

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