DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
14 CFR Part 39
[Docket No. FAA-2008-0264; Directorate Identifier 2008-NE-07-AD] RIN 2120
-AA64
AIRWORTHINESS DIRECTIVES; Honeywell International Inc. TFE731-4, -4R, -5,
-5AR, -5BR, and -5R Series Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), Department of Transportat-
ion (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for
Honeywell International Inc. TFE731-4, -4R, -5, -5AR, -5BR, and -5R series
turbofan engines, with interstage turbine transition (ITT) duct, part
number (P/N) 3075292-1; 3075292-3; 3074766-1; 3077063-1; 3075655-1;
3075655-2; 30756599-1; or 30756599-3, installed. This proposed AD would
require replacing the affected ITT duct with a serviceable and redesigned
ITT duct. This proposed AD results from reports of 49 low pressure turbine
(LPT) blade separations. Six of those events resulted in circumferential
failure of the LPT2 or LPT3 nozzle assembly, leading to deformation of the
ITT duct and uncontainment of the turbine blades and fragments of the LPT
nozzle assembly. We are proposing this AD to prevent uncontainment of
turbine blades and fragments of the LPT nozzle assembly, which could
result in damage to the airplane.
DATES: We must receive any comments on this proposed AD by June 3, 2008.
ADDRESSES: Use one of the following addresses to comment on this proposed
AD.
Federal eRulemaking Portal: Go to http://www.regulations.gov and follow
the instructions for sending your comments electronically.
Mail: Docket Management Facility, U.S. Department of Transportation, 1200
New Jersey Avenue, SE., West Building Ground Floor, Room W12-140,
Washington, DC 20590-0001.
Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: (202) 493-2251.
You can get the service information identified in this proposed AD from
Honeywell Engines and Systems Technical Publications and Distribution, M/S
2101-201, P.O. Box 52170, Phoenix, AZ 85072-2170, telephone: (602) 365
-2493 (General Aviation), (602) 365-5535 (Commercial Aviation), fax: (602)
365-5577 (General Aviation and Commercial Aviation).
FOR FURTHER INFORMATION CONTACT: Joseph Costa, Aerospace Engineer, Los
Angeles Aircraft Certification Office, FAA, Transport Airplane
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail:
joseph.costa@faa.gov; telephone: (562) 627-5246; fax: (562) 627-5210.
SUPPLEMENTARY INFORMATION:
COMMENTS INVITED
We invite you to send us any written relevant data, views, or arguments
regarding this proposal. Send your comments to an address listed under
ADDRESSES. Include "Docket No. FAA-2008-0264; Directorate Identifier 2008
-NE-07-AD" in the subject line of your comments. We specifically invite
comments on the overall regulatory, economic, environmental, and energy
aspects of the proposed AD. We will consider all comments received by the
closing date and may amend the proposed AD in light 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 with
FAA personnel concerning this proposed AD. Using the search function of
the Web site, anyone can find and read the comments in any of our dockets,
including, if provided, the name of the individual who sent the comment
(or signed the comment on behalf of an association, business, labor union,
etc.). You may review the DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78).
EXAMINING THE AD DOCKET
You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 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
Operations office (telephone (800) 647-5527) is the same as the Mail
address provided in the ADDRESSES section. Comments will be available in
the AD docket shortly after receipt.
DISCUSSION
In July 2006, we started receiving reports of LPT blade separations, which
resulted in circumferential failure of the LPT2 or LPT3 nozzle assembly.
To date, we have received reports of 49 LPT blade separations of which 6
of those events caused spinning of the LPT2 or LPT3 nozzle assembly. The
spinning can lead to deformation of the ITT duct and uncontainment of the
turbine blades and fragments of the LPT nozzle assembly. This condition,
if not corrected, could result in uncontainment of turbine blades and
fragments of the LPT nozzle assembly, leading to damage to the airplane.
FAA'S DETERMINATION AND REQUIREMENTS OF THE PROPOSED AD
We have evaluated all pertinent information and identified an unsafe
condition that is likely to exist or develop on other products of this
same type design. We are proposing this AD, which would require replacing
the affected ITT duct with a serviceable and redesigned ITT duct at the
next Major Periodic Inspection of the engine or at next access of the ITT
duct, whichever occurs first, but not to exceed 2,600 hours time-in
-service after the effective date of the proposed AD. The serviceable and
redesigned ITT duct will minimize the potential for uncontained events.
COSTS OF COMPLIANCE
We estimate that this proposed AD would affect 1,500 engines installed on
airplanes of U.S. registry. We also estimate that it would take about 4
work-hours per engine to perform the proposed actions, and that the
average labor rate is $80 per work-hour. Reworked ITT ducts to the
redesign would cost about $25,000 per engine. New ITT ducts that are
redesigned would cost about $127,000. We estimate that 30 engines would
require new ITT ducts. Based on these figures, we estimate the total cost
of the proposed AD to U.S. operators to be $41,040,000.
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 have 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 that the proposed AD:
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. Would not have a significant economic impact, positive or negative, on
a substantial number of small entities under the criteria of the
Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to comply with
this proposed AD. You may get a copy of this summary at the address listed
under ADDRESSES.
LIST OF SUBJECTS IN 14 CFR PART 39
Air transportation, Aircraft, Aviation safety, Safety.
THE PROPOSED AMENDMENT
Under the authority delegated to me by the Administrator, the Federal
Aviation Administration 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 airworthiness
directive: