[Federal Register Volume 61, Number 168 (Wednesday, August 28, 1996)]
[Rules and Regulations]
[Pages 44156-44157]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21742]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-240-AD; Amendment 39-9725; AD 96-18-01]
RIN 2120-AA64


Airworthiness Directives; Learjet 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 60 airplanes, that requires 
modification of the aft core cowl nozzle of the engine nacelles. This 
amendment is prompted by a report that the sealant material in the aft 
core cowl nozzle of the engine nacelle was found to extend higher than 
the nozzle's forward flange, which can allow it to interfere with the 
proper operation of the emergency fuel shutoff actuating mechanism. The 
actions specified by this AD are intended to prevent physical 
interference of the emergency fuel shutoff actuating mechanism and 
resultant engine shutdown.

DATES: Effective October 2, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 2, 1996.

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, Small Airplane Directorate, 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: Jeffrey Janusz, Aerospace Engineer, 
Systems and Propulsion Branch, ACE-116W, FAA, Small Airplane 
Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, 
Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 
946-4148; 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 60 airplanes 
was published in the Federal Register on May 30, 1996 (61 FR 27030). 
That action proposed to require modification of the aft core cowl 
nozzle of the engine nacelles.

Comments

    No comments were submitted in response to the proposal or the FAA's 
determination of the cost to the public. The FAA has determined that 
air safety and the public interest require the adoption of the rule as 
proposed.

Cost Impact

    There are approximately 39 Learjet Model 60 airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 26 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 44 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $60 per work hour. 
Required parts will be supplied by the manufacturer at no cost to the 
operators. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $68,640, or $2,640 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.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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:

96-18-01  Learjet: Amendment 39-9725. Docket 95-NM-240-AD.

    Applicability: Model 60 airplanes, as listed in Learjet Service 
Bulletin SB 60-71-2, dated May 12, 1995; certificated in any 
category.

    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 (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 sealant material in the aft core cowl nozzle of 
the engine nacelles from interfering with the lever of the emergency 
fuel shutoff actuating mechanism, which could result in the failure 
of the emergency fuel shutoff actuating mechanism and resultant 
engine shutdown, accomplish the following:
    (a) Within 90 days after the effective date of this AD, modify 
the aft core cowl nozzle of the engine nacelles in accordance with 
Learjet Service Bulletin SB 60-71-2, dated May 12, 1995.
    (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, Small Airplane Directorate. Operators shall

[[Page 44157]]

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.

    (c) 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.
    (d) The modification shall be done in accordance with Learjet 
Service Bulletin SB 60-71-2, dated May 12, 1995, which includes 
Nordam Service Bulletin PW300L71-1, dated April 26, 1995. 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, 
Small Airplane Directorate, 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.
    (e) This amendment becomes effective on October 2, 1996.

    Issued in Renton, Washington, on August 20, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-21742 Filed 8-27-96; 8:45 am]
BILLING CODE 4910-13-U