Airworthiness Directives; Learjet Model 45 Series Airplanes

[Federal Register Volume 65, Number 212 (Wednesday, November 1, 2000)]
[Rules and Regulations]
[Pages 65257-65258]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-27630]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-132-AD; Amendment 39-11950; AD 2000-22-04]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 45 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Learjet Model 45 series airplanes, that requires 
repetitive application of grease to the rotating disk assembly of the 
nose landing gear squat switch mechanism. Application of grease to the 
squat switch assembly is necessary to prevent moisture contamination 
and subsequent formation of ice. Such ice formation could result in 
bending or damaging of the nose landing gear squat switch assembly, 
which could drive 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 from the runway at high speeds during 
landing.

DATES: Effective December 6, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 6, 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 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: Shane Bertish, Aerospace Engineer, 
Systems and Equipment Branch, ACE-116W, FAA, Small Airplane 
Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, 
Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 
946-4156; fax (316) 946-4407.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Learjet Model 45 series 
airplanes was published in the Federal Register on June 27, 2000 (65 FR 
39578). That action proposed to require repetitive application of 
grease to the rotating disk assembly of the nose landing gear squat 
switch mechanism.

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.

Interim Action

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

Cost Impact

    There are approximately 69 Learjet Model 45 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 45 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 1 work hour per airplane to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the cost impact of the AD on U.S. operators is estimated 
to be $2,700, or $60 per airplane, per application.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of

[[Page 65258]]

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 ``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

    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:

2000-22-04 Learjet: Amendment 39-11950. Docket 2000-NM-132-AD.

    Applicability: Model 45 series airplanes, serial numbers 45-001 
through 45-114 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 the airplane from departing the runway at high speeds 
during landing due to bending and damage to the squat switch 
assembly of the nose landing gear, accomplish the following:

Application of Grease

    (a) Within 30 days after the effective date of this AD, apply 
grease to the rotating disk assembly of the squat switch mechanism 
of the nose wheel in accordance with Bombardier Aerospace Service 
Information Letter SIL 32-016, dated March 30, 2000. Thereafter, 
repeat this application at intervals not to exceed 30 days.

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 Permit

    (c) Special flight permits may be issued in accordance with 
Secs. 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 application of grease shall be done in accordance with 
Bombardier Aerospace Service Information Letter SIL 32-016, dated 
March 30, 2000. 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 December 6, 2000.

    Issued in Renton, Washington, on October 23, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-27630 Filed 10-31-00; 8:45 am]
BILLING CODE 4910-13-P

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