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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2009-0495; Directorate Identifier 2009-NM-049-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Learjet Model 60 airplanes. This proposed AD would require revising the Tire-Servicing section of the airplane maintenance manual and revising the Tires Limitation section of the airplane flight manual to incorporate revised procedures for servicing tires and checking for proper tire inflation. This proposed AD results from a report of the main landing gear tires blowing out during a takeoff roll. We are proposing this AD to prevent tire failure, which could result in failures of the braking and thrust reverser systems. In a critical phase of operation such as takeoff, loss of airplane control may result.

# DATES:

We must receive comments on this proposed AD by July 13, 2009.

# 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:                          U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, 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 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 or 425-227-1152.                    

## 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 (telephone 800-647-5527) is in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after receipt.                

# FOR FURTHER INFORMATION CONTACT:

Don Ristow, Aerospace Engineer, Mechanical Systems and Propulsion Branch, ACE-116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4120; fax (316) 946-4107.

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the                     **ADDRESSES**                     section. Include “Docket No. FAA-2009-0495; Directorate Identifier 2009-NM-049-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                           ( print page 25683)                        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 of all four of the main landing gear tires blowing out during a takeoff roll of a Learjet Model 60 airplane. The airplane overran the end of the runway, ultimately stopping when it struck an embankment, and was destroyed by fire. Investigation of the tire fragments indicates that, in all four tires, there was evidence of internal heat damage consistent with under-inflation, over-loading, or a combination of both; damage to a tire under these conditions is cumulative. Tires that have been rolled or taxied at lower-than-specified tire pressure settings may fail. We are proposing this AD to prevent tire failure, which could result in failures of the braking and thrust reverser systems. In a critical phase of operation such as takeoff, loss of airplane control may result.

## Relevant Service Information

We have reviewed Learjet 60 Temporary Revision (TR) 12-16, dated March 18, 2009, to the Learjet 60 Maintenance Manual; and Learjet 60 Temporary Flight Manual Change (TFMC) 2009-03, dated March 9, 2009, to the Learjet 60 Airplane Flight Manual (AFM) and Learjet 60XR AFM. Learjet 60 TR 12-16 describes the procedures to use when checking for and maintaining proper tire inflation. Learjet 60 TFMC 2009-03 describes procedures to use when checking for proper tire inflation within 96 hours (4 days) prior to takeoff.

## FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the(se) same type design(s). This proposed AD would require accomplishing the actions specified in the service information described previously.

## Costs of Compliance

We estimate that this proposed AD would affect 240 airplanes of U.S. registry. We also estimate that it would take about 1 work-hour per product to comply with this proposed AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $19,200, or $80 per product.

## 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), 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

# 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 

2. The FAA amends § 39.13 by adding the following new AD:

**Learjet:**                                 Docket No. FAA-2009-0495; Directorate Identifier 2009-NM-049-AD.                            

## Comments Due Date

(a) We must receive comments by July 13, 2009.

## Affected ADs

(b) None.

## Applicability

(c) This AD applies to Learjet Model 60 airplanes, certificated in any category, serial numbers 60-002 through 60-369 inclusive.

## Subject

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

## Unsafe Condition

(e) This AD results from a report of the main landing gear tires blowing out during a takeoff roll. The Federal Aviation Administration is issuing this AD to prevent tire failure, which could result in failures of the braking and thrust reverser systems. In a critical phase of operation such as takeoff, loss of airplane control may result.

## Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

## Revise the Maintenance Manual (MM)

(g) Within 14 days after the effective date of this AD, revise the Tire-Servicing section of Learjet 60 MM to include the information in Learjet 60 Temporary Revision (TR) 12-16, dated March 18, 2009.

# Note 1:

 The actions required by paragraph (g) of this AD may be done by inserting a copy of Learjet 60 TR 12-16, dated March 18, 2009, into the Learjet 60 MM. When Learjet 60 TR 12-16 has been included in general revisions of the Learjet 60 MM, the general revisions may be inserted in the MM, provided the relevant information in the general revision is identical to that in the TR.

## Revise the Airplane Flight Manual (AFM)

(h) Within 14 days after the effective date of this AD, revise the Tires Limitations section of the Learjet 60 AFM or Learjet 60XR AFM, as applicable, to include the information in the Learjet 60 Temporary Flight Manual Change (TFMC) 2009-03, dated March 9, 2009. Thereafter, operate the airplane according to the limitations and procedures in the TFMC.

# Note 2:

                                     The actions required by paragraph (h) of this AD may be done by inserting a copy of Learjet 60 TFMC 2009-03, dated March 9, 2009, into the Learjet 60 or 60XR                                           ( print page 25684)                                        AFM, as applicable. When Learjet 60 TFMC 2009-03 has been included in general revisions of the applicable AFM, the general revisions may be inserted in the applicable AFM, provided the relevant information in the general revision is identical to that in Learjet 60 TFMC 2009-03.                                

## Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Wichita Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Don Ristow, Aerospace Engineer, Mechanical Systems and Propulsion Branch, ACE-116W, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4120; fax (316) 946-4107.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

Issued in Renton, Washington, on May 18, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. E9-12522 Filed 5-28-09; 8:45 am]

BILLING CODE 4910-13-P