Airworthiness Directives; Learjet Model 55 Series Airplanes and Model 60 Airplanes

[Federal Register Volume 66, Number 114 (Wednesday, June 13, 2001)]
[Rules and Regulations]
[Pages 31837-31839]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-14530]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-128-AD; Amendment 39-12257; AD 2001-12-02]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 55 Series Airplanes and 
Model 60 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 55 series airplanes and Model 60 
airplanes, that requires replacement of the brake valve adjustment 
screw with a new improved screw, and for certain airplanes, it would 
also require installation of a new brake valve lever stop. The actions 
specified by this AD are intended to prevent bottoming of the valve 
components before contact of the brake valve lever with the stop, which

[[Page 31838]]

could result in loss of all hydraulic fluid and consequent loss of 
normal braking. This action is intended to address the identified 
unsafe condition.

DATES: Effective July 18, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 18, 2001.

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 Propulsion Branch, ACE-116W, FAA, 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 55 series 
airplanes and Model 60 airplanes was published in the Federal Register 
on March 19, 2001 (66 FR 15362). That action proposed to require 
replacement of the brake valve adjustment screw with a new improved 
screw; and for certain airplanes, that action also proposed to require 
installation of a new brake valve lever stop.

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.

Cost Impact

    There are approximately 331 Model 55 series airplanes and Model 60 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 285 airplanes of U.S. registry will be affected by this 
AD, that it will take approximately 16 work hours per airplane to 
accomplish the required actions, and that the average labor rate is $60 
per work hour. Required parts will cost approximately $2,368 per 
airplane. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $948,480, or $3,328 per airplane.
    The cost impact figure discussed above is 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 ``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:

2001-12-02  Learjet: Amendment 39-12257. Docket 2000-NM-128-AD.

    Applicability: Model 55 series airplanes, serial numbers 55-003 
through 55-147 inclusive, and Model 60 airplanes, serial numbers 60-
002 through 60-189 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 bottoming of the valve components before contact of 
the brake valve lever with the stop, which could result in loss of 
all hydraulic fluid and consequent loss of normal braking; 
accomplish the following:

Replacement of Brake Valve Lever Stop Switch

    (a) Within 300 flight hours or one year after the effective date 
of this AD, whichever occurs first, accomplish the actions specified 
in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable.
    (1) For Learjet Model 60 airplanes having serial numbers 60-002 
through 60-093 inclusive, and 60-095 through 60-188 inclusive: 
Replace the existing brake valve lever stop switch with a new brake 
valve lever stop switch, and replace the brake valve adjustment 
screws with new improved screws, per Bombardier Service Bulletin 60-
32-10, Revision 1, dated June 22, 2000.
    (2) For Learjet Model 60 airplanes having serial number 60-094 
or 60-189: Replace the brake valve adjustment screws with new 
improved screws, per Bombardier Service Bulletin 60-32-10, Revision 
1, dated June 22, 2000.
    (3) For Learjet Model 55 series airplanes having serial numbers 
55-003 through 55-147 inclusive: Replace the existing brake valve 
lever stop with a new brake valve lever stop, and replace the brake 
valve adjustment screws with new improved screws, per Bombardier 
Service Bulletin 55-32-14, dated November 9, 1999.

[[Page 31839]]

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, 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 
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 actions shall be done in accordance with Bombardier 
Service Bulletin 60-32-10, Revision 1, dated June 22, 2000; and 
Bombardier Service Bulletin 55-32-14, dated November 9, 1999; as 
applicable. 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 July 18, 2001.

    Issued in Renton, Washington, on June 4, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-14530 Filed 6-12-01; 8:45 am]
BILLING CODE 4910-13-P

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