DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
14 CFR Part 39
[Docket No. FAA-2009-0495; Directorate Identifier 2009-NM-049-AD] RIN
2120-AA64
AIRWORTHINESS DIRECTIVES; Learjet Model 60 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
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, Mechanic-
al 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 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 Proc-
edures (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.
SEC. 39.13 [AMENDED]
2. The FAA amends Sec. 39.13 by adding the following new AD: