[Federal Register Volume 70, Number 232 (Monday, December 5, 2005)]
[Rules and Regulations]
[Pages 72358-72360]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23510]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-23144; Directorate Identifier 2005-NM-218-AD; 
Amendment 39-14393; AD 2005-24-13]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 45 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Learjet Model 45 airplanes. This AD requires modifying the 
electrical wire bundle for the alternator on the left-hand engine, 
inspecting for clearance between wire harnesses and engine tubing for 
each engine, and corrective actions if necessary. For certain 
airplanes, this AD also requires replacing the fuses for the hydraulic 
shutoff valves with fuses having higher amperage. This AD results from 
a report of a fire in the left-hand engine nacelle. We are issuing this 
AD to prevent chafing between the wire bundle for the alternator on 
each engine and the hydraulic lines, which could result in a fire in 
the engine nacelle.

DATES: This AD becomes effective December 20, 2005.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of December 20, 
2005.
    We must receive comments on this AD by February 3, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.

[[Page 72359]]

     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942, 
for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: James P. Galstad, Aerospace Engineer, 
Systems and Propulsion Branch, ACE-116W, FAA, Wichita Aircraft 
Certification Office, 1801 Airport Road, Room 100, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone (316) 946-4135; fax (316) 
946-4107.

SUPPLEMENTARY INFORMATION:

Discussion

    We have received a report of a fire in the left-hand engine nacelle 
on a Learjet Model 45 airplane. Investigation revealed that an 
electrical wire bundle for the engine alternator had chafed a hole in a 
hydraulic line. This condition, if not corrected, could result in a 
fire in the engine nacelle.

Relevant Service Information

    We have reviewed Bombardier Alert Service Bulletin SB A40-71-01, 
dated September 29, 2005 (for Learjet Model 45 airplanes with serial 
numbers (S/Ns) 45-2001 through 45-2029 inclusive); and Bombardier Alert 
Service Bulletin SB A45-71-4, dated September 29, 2005 (for Learjet 
Model 45 airplanes with S/Ns 45-005 through 45-273 inclusive). These 
service bulletins describe procedures for modifying the electrical wire 
bundle for the alternator on the left-hand engine to separate the 
wiring from the hydraulic pump lines and to protect the wiring; 
inspecting the left and right engines to make sure that the proper 
clearances are maintained between all wiring harnesses and engine 
tubing; and correcting improper clearances if necessary. The service 
bulletins also specify sending a compliance report to the manufacturer.
    We have also reviewed Bombardier Service Bulletin SB 40-24-01, 
dated April 22, 2005 (for Learjet Model 45 airplanes with S/Ns 45-2001 
through 45-2015 inclusive); and Bombardier Service Bulletin SB 45-24-6, 
dated April 22, 2005 (for Learjet Model 45 airplanes with serial 
numbers 45-005 through 45-254 inclusive). The actions in these service 
bulletins must be accomplished before or concurrently with Bombardier 
Alert Service Bulletins SB A40-71-01 and SB A45-71-4. Bombardier 
Service Bulletin SB 40-24-01 and SB 45-24-6 describe procedures for 
replacing the fuses for the hydraulic shutoff valves with fuses having 
higher amperage.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to prevent chafing between the wire bundle for the 
alternator on each engine and the hydraulic lines, which could result 
in a fire in the engine nacelle. This AD requires accomplishing the 
actions specified in the applicable service information described 
previously, except as discussed under ``Difference Between the AD and 
Bombardier Alert Service Bulletins SB A40-71-01 and SB A45-71-4.''

Difference Between the AD and Bombardier Alert Service Bulletins SB 
A40-71-01 and SB A45-71-4

    Although Bombardier Alert Service Bulletins SB A40-71-01 and SB 
A45-71-4 specify sending a compliance report to the manufacturer, this 
AD does not include that requirement.

Clarification of Inspection Terminology

    In this AD, the ``inspecting for proper clearance'' specified in 
Bombardier Alert Service Bulletins SB A40-71-01 and SB A45-71-4, is 
referred to as a ``general visual inspection.'' We have included the 
definition for this inspection in a note in the AD.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists to make this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2005-
23144; Directorate Identifier 2005-NM-218-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of that Web 
site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.

Examining the Dockets

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

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

[[Page 72360]]

products identified in this rulemaking action.

Regulatory Findings

    We have determined that 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 the regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2005-24-13 Learjet: Amendment 39-14393. Docket No. FAA-2005-23144; 
Directorate Identifier 2005-NM-218-AD.

Effective Date

    (a) This AD becomes effective December 20, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Learjet Model 45 airplanes, certificated 
in any category; serial numbers (S/Ns) 45-005 through 45-273 
inclusive, and 45-2001 through 45-2029 inclusive.

Unsafe Condition

    (d) This AD results from a report of a fire in the left-hand 
engine nacelle. We are issuing this AD to prevent chafing between 
the wire bundle for the alternator on each engine and the hydraulic 
lines, which could result in a fire in the engine nacelle.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Modification

    (f) Within 50 flight hours after the effective date of this AD: 
Modify the electrical wire bundle for the alternator on the left-
hand engine; and do a general visual inspection of the left and 
right engines to make sure that the proper clearances are maintained 
between all wiring harnesses and engine tubing. Correct improper 
clearances before further flight. Do all actions in accordance with 
the Accomplishment Instructions of the applicable service bulletin 
in paragraph (f)(1) or (f)(2) of this AD.
    (1) For Learjet Model 45 airplanes with S/Ns 45-2001 through 45-
2029 inclusive: Bombardier Alert Service Bulletin SB A40-71-01, 
dated September 29, 2005.
    (2) For Learjet Model 45 airplanes with S/Ns 45-005 through 45-
273 inclusive: Bombardier Alert Service Bulletin SB A45-71-4, dated 
September 29, 2005.

    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.''

Concurrent Requirement

    (g) For airplanes with S/Ns identified in paragraphs (g)(1) and 
(g)(2) of this AD: Before or concurrently with the modification 
required by paragraph (f) of this AD, replace the fuses for the 
hydraulic shutoff valves with fuses having higher amperage in 
accordance with the Accomplishment Instructions of the applicable 
service bulletin in paragraph (g)(1) or (g)(2) of this AD.
    (1) For Learjet Model 45 airplanes with S/Ns 45-2001 through 45-
2015 inclusive: Bombardier Service Bulletin SB 40-24-01, dated April 
22, 2005.
    (2) For Learjet Model 45 airplanes with S/Ns 45-005 through 45-
254 inclusive: Bombardier Service Bulletin SB 45-24-6, dated April 
22, 2005.

No Reporting Requirement

    (h) Although Bombardier Alert Service Bulletin SB A40-71-01, 
dated September 29, 2005; and Bombardier Alert Service Bulletin SB 
A45-71-4, dated September 29, 2005; specify sending a compliance 
report to the manufacturer, this AD does not include that 
requirement.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Wichita Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Material Incorporated by Reference

    (j) You must use the service information listed in Table 1 of 
this AD to perform the actions that are required by this AD, unless 
the AD specifies otherwise. The Director of the Federal Register 
approved the incorporation by reference of these documents in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Learjet, 
Inc., One Learjet Way, Wichita, Kansas 67209-2942, for a copy of 
this service information. You may review copies at the Docket 
Management Facility, U.S. Department of Transportation, 400 Seventh 
Street SW., room PL-401, Nassif Building, Washington, DC; on the 
Internet at http://dms.dot.gov; or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

              Table 1.--Material Incorporated by Reference
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     Bombardier service bulletin                      Date
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Alert Service Bulletin SB A40-71-01..  September 29, 2005.
Alert Service Bulletin SB A45-71-4...  September 29, 2005.
Service Bulletin SB 40-24-01.........  April 22, 2005.
Service Bulletin SB 45-24-6..........  April 22, 2005.
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    Issued in Renton, Washington, on November 18, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-23510 Filed 12-2-05; 8:45 am]
BILLING CODE 4910-13-P