[Federal Register: November 2, 2006 (Volume 71, Number 212)]
[Rules and Regulations]
[Page 64441-64443]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02no06-2]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-24487; Directorate Identifier 2006-NE-13-AD;
Amendment 39-14810; AD 2006-22-13]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney PW4074, PW4074D,
PW4077, PW4077D, PW4084D, PW4090, PW4090-3, and PW4098 Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090,
PW4090-3, and PW4098 turbofan engines, with certain front turbine hub
part numbers installed. This AD requires a onetime visual inspection of
the anti-rotation slots in the front turbine hub, for a machining
nonconformance, and its replacement if the inspection failed. This AD
results from a report of a crack found in an anti-rotation slot of a
front turbine hub, during overhaul shop inspection. The anti-rotation
slot geometry was not machined in conformance with the design drawing
during manufacture. We are issuing this AD to prevent uncontained
engine failure, damage to the airplane, and injury to passengers.
DATES: This AD becomes effective December 7, 2006. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in the regulations as of December 7, 2006.
ADDRESSES: You can get the service information identified in this AD
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone
(860) 565-8770; fax (860) 565-4503.
You may examine the AD docket on the Internet at http://dms.dot.gov
or in Room PL-401 on the plaza level of the Nassif Building, 400
Seventh Street, SW., Washington, DC.
FOR FURTHER INFORMATION CONTACT: Antonio Cancelliere, Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803;
telephone (781) 238-7751; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with a proposed AD. The proposed AD applies to Pratt & Whitney PW4074,
PW4074D, PW4077, PW4077D, PW4084D, PW4090, PW4090-3, and PW4098
turbofan engines, with certain front turbine hub part numbers
installed. We published the proposed AD in the Federal Register on June
9, 2006 (71 FR 33412). That action proposed to require a onetime visual
inspection of the anti-rotation slots in the front turbine hub, for a
machining nonconformance, and its replacement if the inspection failed.
Examining the AD Docket
You may examine the docket that contains the AD, any comments
received, and any final disposition in person at the Docket Management
Facility Docket Office between 9 a.m. and 5 p.m., Monday through
Friday,
[[Page 64442]]
except Federal holidays. The Docket Office (telephone (800) 647-5227)
is located on the plaza level of the Department of Transportation
Nassif Building at the street address stated in ADDRESSES. Comments
will be available in the AD docket shortly after the DMS receives them.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Request To Allow Use of Electro-Chemical Etch
United Airlines requests that we allow using the electro-chemical
etch method for marking parts in this AD, as an alternate marking
method. The commenter states that the electro-chemical etch method is
better because it leaves no raised metal to wear on other mating parts.
We agree, provided that the electro-chemical etch instructions from
Pratt & Whitney are followed. Those instructions can be found in Pratt
& Whitney's Cleaning, Inspection, and Repair Manual, part number
51A750, and in their Standard Practices Manual, part number 585005.
Because the marking instructions are part of the service bulletin
paragraphs that we incorporated by reference, we did not change the AD.
Request To Eliminate Reporting Requirement
United Airlines requests that we eliminate the reporting
requirement of inspection findings, from the AD. The commenter states
that the reporting will not enhance airworthiness. We agree. However,
our proposed AD incorporates by reference paragraphs 1.A. through
1.C.(2) of the Accomplishment Instructions of Pratt & Whitney Service
Bulletin No. PW4G-112-72-282, Revision 1, dated March 3, 2006, which do
not require reporting. We did not change the AD.
Request To Change Compliance Paragraph (e)
Pratt & Whitney requests that we change compliance paragraph (e),
which states that you are responsible for having the actions required
by this AD performed at the next exposure of the rear side of the front
turbine hub after the effective date of this AD, unless the actions
have already been done. They state that this could be interpreted to
mean that the engine must be disassembled and inspected because the
front turbine hub is not at piece-part level.
We agree. We changed paragraph (e) in the AD to read ``you are
responsible for having the actions required by this AD performed at the
next disassembly at piece-part level of the front turbine hub after the
effective date of this AD, unless the actions have already been done.''
Conclusion
We carefully reviewed the available data, including the comments
received, and determined that air safety and the public interest
require adopting the AD with the changes described. We determined that
these changes will neither increase the economic burden on any operator
nor increase the scope of the AD.
Costs of Compliance
We estimate that this AD will affect 117 Pratt & Whitney PW4074,
PW4074D, PW4077, PW4077D, PW4084D, PW4090, PW4090-3, and PW4098
turbofan engines installed on airplanes of U.S. registry. We also
estimate that it will take one work-hour per engine to perform the
actions, and that the average labor rate is $80 per work-hour. A
replacement front turbine hub will cost about $253,000 for a PW4074,
PW4074D, PW4077, PW4077D, or PW4084D engine, and about $283,000 for a
PW4090, PW4090-3, or PW4098 engine. To date, the failure rate of
inspected front turbine hubs is ten per cent. Therefore, we expect the
cost of the AD to U.S. operators to be $3,144,960.
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 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); 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.
We prepared a summary of the costs to comply with this AD and
placed it in the AD Docket. 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, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the Federal Aviation Administration 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:
2006-22-13 Pratt & Whitney: Amendment 39-14810. Docket No. FAA-2006-
24487; Directorate Identifier 2006-NE-13-AD.
Effective Date
(a) This airworthiness directive (AD) becomes effective December
7, 2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Pratt & Whitney PW4074, PW4074D, PW4077,
PW4077D, PW4084D, PW4090, PW4090-3, and PW4098 turbofan engines,
with front turbine hub part numbers 50L761, 52L701, 55L221, 52L901,
53L121, 55L521, and 53L021, installed. These engines are installed
on, but not limited to, Boeing 777 airplanes.
Unsafe Condition
(d) This AD results from a report of a crack found in an anti-
rotation slot of a front turbine hub, during overhaul shop
[[Page 64443]]
inspection. The anti-rotation slot geometry was not machined in
conformance with the design drawing during manufacture. We are
issuing this AD to prevent uncontained engine failure, damage to the
airplane, and injury to passengers.
Compliance
(e) You are responsible for having the actions required by this
AD performed at the next disassembly at piece-part level of the
front turbine hub after the effective date of this AD, unless the
actions have already been done.
Onetime Visual Inspection
(f) For front turbine hubs listed by part number and serial
number in Table 1, Table 2, and Table 3 of Pratt & Whitney Service
Bulletin (SB) No. PW4G-112-72-282, Revision 1, dated March 3, 2006,
do the following:
(1) Perform a onetime visual inspection for extra fillet radii
in the anti-rotation slots.
(2) Use paragraphs 1.A. through 1.C.(2) of the Accomplishment
Instructions of Pratt & Whitney SB No. PW4G-112-72-282, Revision 1,
dated March 3, 2006, to do the inspection.
(3) Remove from service any front turbine hub that has extra
fillet radii in the anti-rotation slots and install a serviceable
front turbine hub.
Prohibition of Front Turbine Hubs That Have Extra Fillet Radii in the
Anti-Rotation Slots
(g) After the effective date of this AD, do not install any
front turbine hub that has extra fillet radii in the anti-rotation
slots, onto any engine.
Previous Credit
(h) Previous credit is allowed for front turbine hubs inspected
using Pratt & Whitney SB No. PW4G-112-72-282, dated February 27,
2006, or Revision 1, dated March 3, 2006, before the effective date
of this AD.
Alternative Methods of Compliance
(i) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance for this AD if
requested using the procedures found in 14 CFR 39.19.
Material Incorporated by Reference
(j) You must use Pratt & Whitney Service Bulletin No. PW4G-112-
72-282, Revision 1, dated March 3, 2006, to perform the actions
required by this AD. The Director of the Federal Register approved
the incorporation by reference of this service bulletin in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Pratt &
Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-
8770; fax (860) 565-4503, for a copy of this service information.
You may review copies at the FAA, New England Region, Office of the
Regional Counsel, 12 New England Executive Park, Burlington, MA; or
at the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call 202-
741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html
.
Issued in Burlington, Massachusetts, on October 24, 2006.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E6-18368 Filed 11-1-06; 8:45 am]
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