Airworthiness Directives; Learjet Model 31, 31A, 35, 35A, and 60 Airplanes

[Federal Register Volume 64, Number 220 (Tuesday, November 16, 1999)]
[Rules and Regulations]
[Pages 62108-62109]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-29470]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-15-AD; Amendment 39-11415; AD 99-23-19]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 31, 31A, 35, 35A, and 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 31, 31A, 35, 35A, and 60 airplanes, 
that requires a visual inspection of the spoiler actuators to determine 
the serial number of the spoiler actuators; and replacement of the 
spoiler actuators with new actuators, if necessary. This amendment is 
prompted by failure of a spoiler actuator piston rod during the first 
production flight of a Model 60 airplane due to an incomplete heat 
treatment process. The actions specified by this AD are intended to 
prevent failure of the spoiler actuator, which could result in the 
spoiler panel floating and inducing an uncommanded roll of the 
airplane.

DATES: Effective December 21, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 21, 1999.

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, Small 
Airplane Directorate, 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 31, 31A, 35, 
35A, and 60 airplanes was published in the Federal Register on August 
30, 1999 (64 FR 47148). That action proposed to require a visual 
inspection of the spoiler actuators to determine the serial number of 
the spoiler actuators; and replacement of the spoiler actuators with 
new actuators, if necessary.

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 45 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 37 airplanes of U.S. registry 
will be affected by this AD, that it will take approximately 1 work 
hour per airplane to accomplish the inspection, and that the average 
labor rate is $60 per work hour. Based on these figures, the cost 
impact of this AD on U.S. operators is estimated to be $2,220, or $60 
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:

99-23-19 Learjet, Inc.: Amendment 39-11415. Docket 99-NM-15-AD.
    Applicability: Model 31 and 31A airplanes, serial numbers 31-
033, 31-105, 31-114, 31-126, and 31-150 through 31-161 inclusive; 
Model 35 and 35A airplanes, serial numbers 35-065, 35-242, 35-300, 
35-323, 35-447, 35-622, and 35-670; and Model 60 airplanes, serial 
numbers 60-029, 60-050, 60-120 through 60-139 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

[[Page 62109]]

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 failure of the spoiler actuator, which could result 
in the spoiler panel floating and inducing an uncommanded roll of 
the airplane, accomplish the following:

Inspection and Replacement

    (a) Within 150 flight hours after the effective date of this AD, 
perform a visual inspection to determine the serial number of the 
spoiler actuators, in accordance with Learjet Service Bulletins SB 
31-27-19, dated December 14, 1998 (for Model 31 and 31A airplanes); 
SB 35-27-36, dated December 14, 1998 (for Model 35 and 35A 
airplanes); or SB 60-27-21, dated December 14, 1998 (for Model 60 
airplanes); as applicable.
    (1) If the serial number is not listed in the applicable service 
bulletin, no further action is required by this AD.
    (2) If the serial number is listed in the applicable service 
bulletin, prior to further flight, replace the spoiler actuators 
with new actuators in accordance with the Accomplishment 
Instructions of the applicable service bulletin.

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, Small Airplane Directorate. 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 Learjet Service 
Bulletin SB 31-27-19, dated December 14, 1998, Learjet Service 
Bulletin SB 35-27-36, dated December 14, 1998, or Learjet Service 
Bulletin SB 60-27-21, dated December 14, 1998, 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, Small Airplane Directorate, 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.
    (e) This amendment becomes effective on December 21, 1999.

    Issued in Renton, Washington, on October 28, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-29470 Filed 11-15-99; 8:45 am]
BILLING CODE 4910-13-U

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