2011-27010. Airworthiness Directives; Learjet Inc. Model 45 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

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 include new or more restrictive life-limits and inspections. This proposed 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. We are proposing 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.

DATES:

We must receive comments on this proposed AD by December 5, 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: [phone].
• 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; phone [phone]; fax [phone]; e-mail [e-mail]; 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.

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: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

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: [phone]; fax: [phone]; e-mail: [e-mail].

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-2011-1069; Directorate Identifier 2011-NM-025-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 have reviewed the design approval holder's changes to the ALS of the maintenance manual, which adds life-limits, revises life-limits, or adds inspections not previously identified. These changes resulted from the design holder's analysis, testing, and in-service history of certain components. We are proposing 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. The corrective action is revising the maintenance program.

Relevant Service Information

We reviewed Chapter 04, Airworthiness Limitations, of the Bombardier Learjet 45 Maintenance Manual MM-104, Revision 53, dated January 10, 2011; and Bombardier Learjet 40 Maintenance Manual MM-105, Revision 21, dated January 10, 2011. This service information describes component and system checks and replacements and includes new or revised life-limits and new inspections.

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 the same type design.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD affects 336 of U.S. registry.

We estimate the following costs to comply with this proposed AD:

Estimated Costs

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

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:

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.

§ 39.13

[Amended]

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

Learjet Inc.: Docket No. FAA-2011-1069; Directorate Identifier 2011-NM-025-AD.

Comments Due Date

(a) We must receive comments by December 5, 2011.

Affected ADs

(b) None

Applicability

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

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 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 Advisory Circular (AC) 25.1529-1A.

Subject

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

Unsafe Condition

(e) 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.

Compliance

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

Maintenance Program Revision

(g) 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 2:

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

Model—	IRN #—	Initial compliance time—	Chapter 04 of these documents—
Model 40, 45	R2710041	Within 10 years after the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness, or within 10 years after the most recent replacement, whichever occurs later	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.
Model 40, 45	Q5510091	Within 600 flight hours after the most recent inspection done in accordance with IRN # Q5510091	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.
Model 40, 45	Q5530011	Before the accumulation of 9,600 total flight hours	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.
Model 40, 45	P3220007	Within 48 months after the most recent inspection done in accordance with IRN # P3220007	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.
Model 40, 45	P3220146	Before the accumulation of 4,800 total landings	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.
Model 40, 45	N3220012, N3220023, N3220035, N3220036, and N3220037	Before the accumulation of 10,000 total landings on the component	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.
Model 40, 45	N3220103, N3220104, N3220105, and N3220106	Before the accumulation of 17,000 total landings on the component	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.
Model 45	N5710147, N5710171, and N5710173	Before the accumulation of 6,500 total flight hours	Bombardier Learjet 45 Maintenance Manual MM-104, Revision 53, dated January 10, 2011.
Model 45	N5710175	Before the accumulation of 6,900 total flight hours	Bombardier Learjet 45 Maintenance Manual MM-104, Revision 53, dated January 10, 2011.
Model 45	N5710177	Before the accumulation of 7,000 total flight hours	Bombardier Learjet 45 Maintenance Manual MM-104, Revision 53, dated January 10, 2011.

No Alternative Intervals

(h) After accomplishing the revisions required by paragraphs (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.

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.

Related Information

(j) For more information about this AD, contact 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: [phone]; fax: [phone]; e-mail: [e-mail].

(k) For service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942; telephone [phone]; fax [phone]; e-mail [e-mail]; 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 October 5, 2011.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.