
[Federal Register Volume 76, Number 131 (Friday, July 8, 2011)]
[Proposed Rules]
[Pages 40291-40293]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-17265]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0651; Directorate Identifier 2011-NM-041-AD]
RIN 2120-AA64


Airworthiness Directives; Learjet Inc. Model 45 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed AD would require revising the 
maintenance program to incorporate life limits for the main landing 
gear (MLG) actuator end cap. This proposed AD was prompted by a report 
of the potential for fatigue cracking of the end cap of the MLG prior 
to the published life limitation. We are proposing this AD to prevent 
fatigue cracking of the end cap of the MLG, which could result in the 
failure of the MLG actuator upon landing, and failure of the MLG to 
extend or retract during flight.

DATES: We must receive comments on this proposed AD by August 22, 2011.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942; telephone 
316-946-2000; fax 316-946-2220; e-mail ac.ict@aero.bombardier.com; 
Internet http://www.bombardier.com. You may

[[Page 40292]]

review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at the 
FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Paul Chapman, Aerospace Engineer, 
Aviation Safety, ACE-118W, FAA, Wichita Aircraft Certification Office, 
1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, KS 67209; 
phone: 316-946-4152; fax: 316-946-4107; e-mail: paul.chapman@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2011-0651; 
Directorate Identifier 2011-NM-041-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We received a report from Learjet that indicated the life 
limitation of the main landing gear actuator was determined using 
fatigue testing during the Model 45 certification; however, the 
supplier discovered they had not tested the actuator properly during 
subsequent testing for another application. Learjet identified the 
potential for fatigue cracking of the end cap of the main landing gear 
actuator prior to the published life limitation. This potential for 
fatigue cracking, if not corrected, could result in failure of the main 
landing gear actuator upon landing, and failure of the MLG to extend or 
retract during flight.

Relevant Service Information

    We reviewed Learjet 40 Temporary Revision 4-23, dated January 24, 
2011, to Learjet 40 Maintenance Manual MM-105; and Learjet 45 Temporary 
Revision 4-34, dated January 24, 2011, to Learjet 45 Maintenance Manual 
MM-104. Among other things, the Airworthiness Limitations sections 
contained in Learjet 40 Temporary Revision 4-23 and Learjet 45 
Temporary Revision 4-34 provide new life limits and replacement 
compliance times for the MLG actuator end cap.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

Proposed AD Requirements

    This proposed AD would require revising the maintenance program to 
incorporate life limits for the MLG actuator end cap.

Costs of Compliance

    We estimate that this proposed AD affects 351 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                                                   Cost on U.S.
               Action                      Labor cost        Parts cost      Cost per product       operators
----------------------------------------------------------------------------------------------------------------
Revise maintenance plan............  1 work-hour x $85 per           $0   $85 per revision.....         $29,835
                                      hour = $85 per
                                      revision.
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

[[Page 40293]]

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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Learjet Inc.: Docket No. FAA-2011-0651; Directorate Identifier 2011-
NM-041-AD.

Comments Due Date

    (a) We must receive comments by August 22, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Learjet Inc. Model 45 airplanes, 
certificated in any category; all serial numbers.

    Note 1:  This AD requires revisions to certain operator 
maintenance documents to include new actions (e.g. inspections). 
Compliance with these actions is required by 14 CFR 91.403(c). For 
airplanes that have been previously modified, altered, or repaired 
in the areas addressed by these actions, the operator may not be 
able to accomplish the actions described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance according 
to paragraph (i) of this AD. The request should include a 
description of changes to the required actions that will ensure the 
continued operational safety of the airplane.

Subject

    (d) Air Transport Association (ATA) of America Code 32: Landing 
Gear.

Unsafe Condition

    (e) This AD was prompted by a report of the potential for 
fatigue cracking of the end cap of the main landing gear (MLG) prior 
to the published life limitation. We are issuing this AD to prevent 
fatigue cracking of the end cap of the MLG, which could result in 
the failure of the MLG actuator upon landing, and failure of the MLG 
to extend or retract during flight.

Compliance

    (f) Comply with this AD within the compliance times specified, 
unless already done.

Maintenance Program Revision

    (g) Within 30 days after the effective date of this AD, revise 
the maintenance program by incorporating IRN T3220105 (Main Landing 
Gear Actuator End Cap (P/N 200-0303)) as specified in Learjet 40 
Temporary Revision 4-23, dated January 24, 2011, to Learjet 40 
Maintenance Manual MM-105; or Learjet 45 Temporary Revision 4-34, 
dated January 24, 2011, to Learjet 45 Maintenance Manual MM-104; as 
applicable. The initial compliance for the replacement specified in 
IRN T3220105 is prior to the accumulation of 2,387 total flight 
cycles on the end cap (P/N 200-0303), or within 25 flight cycles 
after the effective date of this AD, whichever occurs later.

No Alternative Actions or Intervals

    (h) After accomplishing the revision required by paragraph (g) 
of this AD, no alternative actions (e.g., replacements) or 
intervals, may be used, unless the actions or intervals are approved 
as an alternative method of compliance (AMOC) in accordance with the 
procedures specified in paragraph (i) of this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Wichita Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office. The AMOC approval letter must specifically 
reference this AD.

Related Information

    (j) For more information about this AD, contact Paul Chapman, 
Aerospace Engineer, Aviation Safety, ACE-118W, FAA, Wichita Aircraft 
Certification Office, 1801 Airport Road, Room 100, Mid-Continent 
Airport, Wichita, KS 67209; phone: 316-946-4152; fax: 316-946-4107; 
e-mail: paul.chapman@faa.gov.
    (k) For service information identified in this AD, contact 
Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942; 
telephone 316-946-2000; fax 316-946-2220; e-mail 
ac.ict@aero.bombardier.com; Internet http://www.bombardier.com. You 
may review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at 
the FAA, call 425-227-1221.

    Issued in Renton, Washington, on June 29, 2011.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-17265 Filed 7-7-11; 8:45 am]
BILLING CODE 4910-13-P


