AD 2012-08-08

We are adopting a new airworthiness directive (AD) for all Learjet Inc., Model 45 airplanes. This AD was prompted by changes to the Airworthiness Limitations Section (ALS) of the maintenance manual, which adds life-limits, revises life-limits, or adds inspections not previously identified. This AD requires revising the maintenance program to include new or more restrictive life-limits and inspections. We are issuing this AD to limit exposure of flight critical components to corrosion, cracking, or failure due to life-limits, which if not corrected, could result in loss of roll control, fatigue cracking, or loss of structural components.

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):

2012-08-08 Learjet Inc.: Amendment 39-17025; Docket No. FAA-2011- 1069; Directorate Identifier 2011-NM-025-AD.

(a) Effective Date

This AD is effective May 29, 2012.

(b) Affected ADs

None

(c) Applicability

(1) This AD applies to all Learjet Inc., Model 45 airplanes, certificated in any category.
(2) 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 inspections 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. The FAA has provided guidance for this determination in FAA Advisory Circular (AC) 25.1529-1A, dated November 20, 2007. http://rgl.faa.gov/Regulatory-- and--Guidance--Library/rgAdvisoryCircular.nsf/list/AC%2025.1529-1A/ $FILE/AC%2025.1529-1A.pdf.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 05, Periodic Inspections.

(e) Unsafe Condition

This AD was prompted by changes to the Airworthiness Limitations Section (ALS) of the maintenance manual (MM), which adds life- limits, revises life-limits, or adds inspections not previously identified. We are issuing this AD to limit exposure of flight critical components to corrosion, cracking, or failure due to life- limits, which if not corrected, could result in loss of roll control, fatigue cracking, or loss of structural components.

(f) Compliance

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

(g) Maintenance Program Revision

Within 90 days after the effective date of this AD, revise the maintenance program by incorporating the applicable inspection reference number (IRN) tasks identified in table 1 of this AD, as specified in Chapter 04, Airworthiness Limitations, of the Bombardier Learjet 45 Maintenance Manual MM-104, Revision 53, dated January 10, 2011; or Bombardier Learjet 40 Maintenance Manual MM- 105, Revision 21, dated January 10, 2011; as applicable. The initial task compliance time is within 90 days after the effective date of this AD, or the applicable initial compliance time specified in table 1 of this AD, whichever is later.
Note 1 to paragraph (g) of this AD: IRN R2710041 shown in table 1 of this AD is identified as IRN N2710041 in prior revisions of Bombardier Learjet 45 Maintenance Manual MM-104, and Bombardier Learjet 40 Maintenance Manual MM-105.

Table 1--IRN Task Revision ----------------------------------------------------------------------------------------------------------------
Chapter 04 of these
Model-- IRN -- Initial compliance time-- documents-- ---------------------------------------------------------------------------------------------------------------- Model 40, 45...................... R2710041............. Within 10 years after the Bombardier Learjet 45
date of issuance of the Maintenance Manual MM-
original standard 104, Revision 53, dated
airworthiness certificate January 10, 2011; or
or the date of issuance Bombardier Learjet 40
of the original export Maintenance Manual MM-
certificate of 105, Revision 21, dated
airworthiness, or within January 10, 2011; as
10 years after the most applicable.
recent replacement,
whichever occurs later. Model 40, 45...................... Q5510091............. Within 600 flight hours Bombardier Learjet 45
after the most recent Maintenance Manual MM-
inspection done in 104, Revision 53, dated
accordance with IRN January 10, 2011; or
Q5510091. Bombardier Learjet 40
Maintenance Manual MM-
105, Revision 21, dated
January 10, 2011; as
applicable. Model 40, 45...................... Q5530011............. Before the accumulation of Bombardier Learjet 45
9,600 total flight hours. Maintenance Manual MM-
104, Revision 53, dated
January 10, 2011; or
Bombardier Learjet 40
Maintenance Manual MM-
105, Revision 21, dated
January 10, 2011; as
applicable. Model 40, 45...................... P3220007............. Within 48 months after the Bombardier Learjet 45
most recent inspection Maintenance Manual MM-
done in accordance with 104, Revision 53, dated
IRN P3220007. January 10, 2011; or
Bombardier Learjet 40
Maintenance Manual MM-
105, Revision 21, dated
January 10, 2011; as
applicable.

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Model 40, 45...................... P3220146............. Before the accumulation of Bombardier Learjet 45
4,800 total landings. Maintenance Manual MM-
104, Revision 53, dated
January 10, 2011; or
Bombardier Learjet 40
Maintenance Manual MM-
105, Revision 21, dated
January 10, 2011; as
applicable. Model 40, 45...................... N3220012, N3220023, Before the accumulation of Bombardier Learjet 45
N3220035, N3220036, 10,000 total landings on Maintenance Manual MM-
and N3220037. the component. 104, Revision 53, dated
January 10, 2011; or
Bombardier Learjet 40
Maintenance Manual MM-
105, Revision 21, dated
January 10, 2011; as
applicable. Model 40, 45...................... N3220103, N3220104, Before the accumulation of Bombardier Learjet 45
and N3220106. 17,000 total landings on Maintenance Manual MM-
the component. 104, Revision 53, dated
January 10, 2011; or
Bombardier Learjet 40
Maintenance Manual MM-
105, Revision 21, dated
January 10, 2011; as
applicable. Model 45.......................... N5710147, N5710171, Before the accumulation of Bombardier Learjet 45
and N5710173. 6,500 total flight hours. Maintenance Manual MM-
104, Revision 53, dated
January 10, 2011. Model 45.......................... N5710175............. Before the accumulation of Bombardier Learjet 45
6,900 total flight hours. Maintenance Manual MM-
104, Revision 53, dated
January 10, 2011. Model 45.......................... N5710177............. Before the accumulation of Bombardier Learjet 45
7,000 total flight hours. Maintenance Manual MM-
104, Revision 53, dated
January 10, 2011. ----------------------------------------------------------------------------------------------------------------

(h) No Alternative Intervals

After accomplishing the revisions required by paragraph (g) of this AD, no alternative IRN task or IRN task interval may be used unless the IRN task or IRN task interval is approved as an AMOC in accordance with the procedures specified in paragraph (i)(1) 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 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.

(j) Related Information

For more information about this AD, William Griffith, Aerospace Engineer, Airframe Branch, ACE-118W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; phone: 316-946-4116; fax: 316-946- 4107; email: William.E.Griffith@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) of the following service information under 5 U.S.C. 552(a) and 1 CFR part 51:
(i) Chapter 04, Airworthiness Limitations, of the Bombardier Learjet 45 Maintenance Manual MM-104, Revision 53, dated January 10, 2011. Only the title page and record of revisions pages of this document specify the revision level of the document.
(ii) Chapter 04, Airworthiness Limitations, of the Bombardier Learjet 40 Maintenance Manual MM-105, Revision 21, dated January 10, 2011. Only the title page and record of revisions pages of this document specify the revision level of the document.
(2) 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; 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 alsoreview 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 was published in the Federal Register on October 19, 2011 (76 FR 64851). That NPRM proposed to require revising the maintenance program to include new or more restrictive life-limits and inspections.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comment received on the proposal and the FAA's response to the comment.

Request To Revisit Interpretation of the Meaning of the Word ``Current''

Flight Concepts requested we revisit our interpretation of the word ``current'' so that the improper use of the airworthiness directive system would not be needed. This commenter justified its request by providing Webster's definition of the word ``current.''
We infer that the requested change is in reference to an FAA memorandum regarding the legal interpretation of section 91.409(f)(3) of the Federal Aviation Regulations (14 CFR 91.409) and is not specifically applicable to this AD.
We do not agree that the word ``current'' needs to be defined for this AD. The utilization of the word ``current'' is not within the textual body of this AD. This AD requires revising the maintenance program by incorporating certain tasks, which when performed, address unsafe conditions. Operators utilizing earlier versions of manual- specific maintenance programs may not be bound or obligated to follow newer releases or updates to these maintenance programs. The issue of the terminology of the word ``current'' and explanation of the requirement for FAA mandates to newer maintenance actions via the AD process is addressed in an FAA memorandum dated August 13, 2010, from the Office of the Chief Counsel. This AD ensures that those specific tasks covering the unsafe conditions are followed by all operators of this airplane model. We have not changed the AD in this regard.

Explanation of Additional Changes Made to This AD

We have redesignated Note 1 of the NPRM (76 FR 64851, October 19, 2011) as paragraph (c)(2) of this AD, paragraph (c) as paragraph (c)(1) of this AD, and Note 2 of the NPRM as Note 1 to paragraph (g) of this AD.
IRN N3220105 was incorrectly included in table 1 of the NPRM (76 FR 64851, October 19, 2011). We have removed it from the final rule.

Conclusion

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD as proposed, except for minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the NPRM (76 FR 64851, October 19, 2011) for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM (76 FR 64851, October 19, 2011).

Costs of ComplianceWe estimate that this AD affects 336 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs ----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Change ALS in maintenance manual.... 1 work-hour x $85 per $0 $85 $28,560
hour = $85. ----------------------------------------------------------------------------------------------------------------

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

[[Page 24346]]

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.