AD 2011-25-03

We are adopting a new airworthiness directive (AD) for all Learjet Inc. Model 45 airplanes. 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. This AD requires revising the maintenance program to incorporate life limits for the MLG actuator end cap. 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.

Final rule.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0 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]

0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): 2011-25-03 Learjet Inc.: Amendment 39-16879; Docket No. FAA-2011- 0651; Directorate Identifier 2011-NM-041-AD.

(a) Effective Date

This AD is effective January 23, 2012.

(b) Affected ADs

None.

(c) Applicability

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.

(d) Subject

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

(e) Unsafe Condition

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.

(f) Compliance

Comply with thisAD within the compliance times specified, unless already done.

(g) Maintenance Program Revision

Within 30 days after the effective date of this AD, revise the maintenance program by incorporating inspection reference number (IRN) T3220105 (Main Landing Gear Actuator End Cap (part number (P/ N) 200-0303)), as specified in Learjet 40 Temporary Revision 4-23, dated January 24, 2011, to Learjet 40 Maintenance Manual; or Learjet 45 Temporary Revision 4-34, dated January 24, 2011, to Learjet 45 Maintenance Manual; as applicable. The initial compliance time 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.

(h) No Alternative Actions or Intervals

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.

(i) Alternative Methods of Compliance (AMOCs)

(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 FR 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.

(j) Related Information

For more information about this AD, contact Paul Chapman, Aerospace Engineer, Airframe and Services Branch, ACE-118W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, KS 67209; phone: (316) 946-4152; fax: (316) 946-4129; email: paul.chapman@faa.gov.

(k) Material Incorporated by Reference

(1) You must use the following service information to do the actions required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51 of the following service information on the date specified:
(i) Learjet 40 Temporary Revision 4-23, dated January 24, 2011, to Learjet 40 Maintenance Manual, approved for IBR January 23, 2012.
(ii) Learjet 45 Temporary Revision 4-34, dated January 24, 2011, to Learjet 45 Maintenance Manual, approved for IBR January 23, 2012.
(2) For Learjet service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942; telephone (316) 946-2000; fax (316) 946-2220; email ac.ict@aero.bombardier.com; Internet http://www.bombardier.com.
(3) 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.
(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM published in the Federal Register on July 8, 2011 (76 FR 40291). That NPRM proposed to require revising the maintenance program to incorporate life limits for the MLG actuator end cap.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (76 FR 40291, July 8, 2011) or on the determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and the public interest require adopting the AD as proposed.

Costs of Compliance

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

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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

This AD will not have federalism implications under Executive Order 13132. This AD 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.
For the reasons discussed above, I certify that this AD:
(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),
(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.