[Federal Register Volume 68, Number 161 (Wednesday, August 20, 2003)]
[Rules and Regulations]
[Pages 50057-50058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-21155]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-13-AD; Amendment 39-13283; AD 2003-17-08]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 45 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Learjet Model 45 airplanes, that currently 
requires repetitive application of grease to the rotating disk assembly 
of the nose landing gear (NLG) squat switch mechanism. This amendment 
requires replacement of the squat switch camrod of the NLG, which 
terminates the repetitive application; and also reduces the 
applicability of the existing AD. The actions specified by this AD are 
intended to prevent moisture contamination and subsequent formation of 
ice which could cause bending and damage of the squat switch assembly, 
driving the nose wheel to an uncommanded angle against the force of the 
steering system. This condition, if not corrected, could result in the 
airplane departing the runway at high speeds during landing. This 
action is intended to address the identified unsafe condition.

DATES: Effective September 24, 2003.
    The incorporation by reference of Bombardier Service Bulletin SB 
45-32-8, Revision 2, dated March 14, 2001, as listed in the 
regulations, is approved by the Director of the Federal Register as of 
September 24, 2003.
    The incorporation by reference of Bombardier Service Information 
Letter SIL 32-016, dated March 30, 2000, as listed in the regulations, 
was approved previously by the Director of the Federal Register as of 
December 6, 2000 (65 FR 65257, November 1, 2000).

ADDRESSES: 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 Federal Aviation 
Administration (FAA), Transport Airplane Directorate, Rules Docket, 
1601 Lind Avenue, SW., Renton, Washington; or at the 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: Robert Busto, Aerospace Engineer, 
Systems and Equipment Branch, ACE-116W, FAA, Wichita Aircraft 
Certification Office, 1801 Airport Road, Room 100, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone (316) 946-4157; fax (316) 
946-4107.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 2000-22-04, 
amendment 39-11950 (65 FR 65257, November 1, 2000), which is applicable 
to certain Learjet 45 series airplanes, was published in the Federal 
Register on May 29, 2003 (68 FR 31999). The action proposed to require 
repetitive application of grease to the rotating disk assembly of the 
nose landing gear (NLG) squat switch mechanism. The action also 
proposed to require replacement of the squat switch camrod of the NLG, 
which would terminate the repetitive application; and would reduce the 
applicability of the existing AD. That action was prompted by tests 
conducted by the manufacturer that indicated a potential unsafe 
condition exists involving damage or bending of the squat switch 
assembly of the NLG due to moisture contamination and subsequent 
formation of ice.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance (AMOCs). Because we have now included this material in part 
39, only the office authorized to approve AMOCs is identified in each 
individual AD. However, for clarity and consistency in this final rule, 
we have retained the language of the NPRM regarding that material.

Change to Labor Rate Estimate

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, reflects 
this increase in the specified hourly labor rate.

Cost Impact

    There are approximately 110 airplanes of U.S. registry that will be 
affected by this AD.
    The actions that are currently required by AD 2000-22-04 take 
approximately 1 work hour per airplane to accomplish, at an average 
labor rate of $65 per work hour. Based on these figures, the cost 
impact of the previously required actions on U.S. operators is 
estimated to be $7,150, or $65 per airplane.
    The new actions that are required by this new AD will take 
approximately 3 work hours per airplane to accomplish, at an average 
labor rate of $65 per work hour. Required parts will cost approximately 
$205 per airplane. Based on these figures, the cost impact of the new 
requirements of this AD on U.S. operators is estimated to be $44,000, 
or $400 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a

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``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. A final 
evaluation has been prepared for this action and it is contained in the 
Rules Docket. A copy of it 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

0
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

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. Section 39.13 is amended by removing amendment 39-11950 (65 FR 
65257, November 1, 2000), and by adding a new airworthiness directive 
(AD), amendment 39-13283, to read as follows:

2003-17-08 Learjet: Amendment 39-13283. Docket 2002-NM-13-AD. 
Supersedes AD 2000-22-04, Amendment 39-11950.

    Applicability: Model 45 airplanes, certificated in any category; 
serial numbers (S/N) 45-005 through 45-071 inclusive, that have been 
modified per Bombardier Service Bulletin 45-32-3; and S/Ns 45-072 
through 45-114 inclusive.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (c)(1) 
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 moisture contamination and subsequent formation of 
ice which could cause bending and damage of the squat switch 
assembly of the nose landing gear (NLG), driving the nose wheel to 
an uncommanded angle against the force of the steering system, and 
consequently resulting in the airplane departing the runway at high 
speeds during landing, accomplish the following:

Restatement of Requirements of AD 2000-22-04, Amendment 39-11950

Application of Grease

    (a) Within 30 days after December 6, 2000 (the effective date of 
AD 2000-22-04, amendment 39-11950): Apply grease to the rotating 
disk assembly of the squat switch mechanism of the nose wheel in 
accordance with Bombardier Service Information Letter SIL 32-016, 
dated March 30, 2000. Thereafter, repeat this application at 
intervals not to exceed 30 days until the replacement required by 
paragraph (b) of this AD is accomplished.

New Requirements of This AD

Terminating Action

    (b) Within 300 flight hours or 12 months after the effective 
date of this AD, whichever occurs first: Replace the camrod of the 
squat switch assembly of the NLG with a new assembly in accordance 
with the Accomplishment Instructions of Bombardier Service Bulletin 
SB 45-32-8, Revision 2, dated March 14, 2001. Accomplishment of the 
camrod replacement terminates the requirements of this AD.

Alternative Methods of Compliance

    (c)(1) 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2000-22-04, amendment 39-11950, are approved as 
alternative methods of compliance with this AD.

    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

    (d) 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

    (e) The actions shall be done in accordance with Bombardier 
Service Information Letter SIL 32-016, dated March 30, 2000; and 
Bombardier Service Bulletin SB 45-32-8, Revision 2, dated March 14, 
2001; as applicable.
    (1) The incorporation by reference of Bombardier Service 
Bulletin SB 45-32-8, Revision 2, dated March 14, 2001, is approved 
by the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51.
    (2) The incorporation by reference of Bombardier Service 
Information Letter SIL 32-016, dated March 30, 2000, was approved 
previously by the Director of the Federal Register as of December 6, 
2000 (65 FR 65257, November 1, 2000).
    (3) 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 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

    (f) This amendment becomes effective on September 24, 2003.

    Issued in Renton, Washington, on August 13, 2003.
Kyle L. Olsen,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-21155 Filed 8-19-03; 8:45 am]
BILLING CODE 4910-13-P