[Federal Register Volume 61, Number 102 (Friday, May 24, 1996)]
[Rules and Regulations]
[Pages 26090-26091]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12730]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-197-AD; Amendment 39-9632; AD 96-11-07]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 31 and 35A 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 and 35A airplanes, that requires 
replacement of two segments of 16 American Wire Gauge (AWG) wire with 8 
AWG wire at the connector that is connected to the auxiliary cabin 
heater relay box. This amendment is prompted by a report that two 
segments of the 16 AWG wire in the auxiliary cabin heater that were 
spliced during production do not provide adequate current-carrying 
capacity. The actions specified by this AD are intended to prevent 
electrical arcing and a subsequent fire hazard that could result from 
wiring with inadequate current-carrying capacity.

DATES: Effective June 28, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 28, 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: Dale Bleakney, Aerospace Engineer, 
Flight Test Branch, ACE-117W, FAA, Small Airplane Directorate, Wichita 
Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-
Continent Airport, Wichita, Kansas; telephone (316) 946-4135; 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 and 35A 
airplanes was published in the Federal Register on March 7, 1996 (61 FR 
9119). That action proposed to require replacement of two segments of 
16 AWG wire with 8 AWG wire at the P190 connector that is connected to 
the E33 auxiliary cabin heater relay box.
    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 52 Learjet Model 31 and 35A airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 44 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 4 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 $10,560, or $240 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

[[Page 26091]]

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:

96-11-07  Learjet, Inc.: Amendment 39-9632. Docket 95-NM-197-AD.

    Applicability: Model 31 airplanes having serial numbers 31-002 
through 31-029 inclusive, and Model 35A airplanes having serial 
numbers 35-647 through 35-670 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 electrical arcing and subsequent fire hazard, 
accomplish the following:
    (a) Within 6 months after the effective date of this AD, replace 
two segments of 16 American Wire Gauge (AWG) wire with 8 AWG wire at 
the P190 connector that is connected to the E33 auxiliary cabin 
heater relay box, in accordance with Learjet Service Bulletin SB 31-
21-10, dated August 11, 1995 (for Model 31 airplanes), or Learjet 
Service Bulletin SB 35-21-24, dated August 11, 1995 (for Model 35A 
airplanes), as applicable.
    (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.

    (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 replacement shall be done in accordance with Learjet 
Service Bulletin SB 31-21-10, dated August 11, 1995, or Learjet 
Service Bulletin SB 35-21-24, dated August 11, 1995, 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, 
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 June 28, 1996.

    Issued in Renton, Washington, on May 15, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12730 Filed 5-23-96; 8:45 am]
BILLING CODE 4910-13-U