Airworthiness Directives; Pratt & Whitney PW4077D, PW4084D, PW4090, and PW4090-3 Turbofan Engines

[Federal Register Volume 71, Number 163 (Wednesday, August 23, 2006)]
[Rules and Regulations]
[Pages 49335-49337]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-13909]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24034; Directorate Identifier 2006-NE-05-AD; 
Amendment 39-14729; AD 2006-17-08]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4077D, PW4084D, 
PW4090, and PW4090-3 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 (PW) PW4077D, PW4084D, PW4090, and PW4090-3 turbofan 
engines that were reassembled with certain previously used high 
pressure compressor (HPC) exit brush seal assembly parts and certain 
new or refurbished HPC exit diffuser air seal inner lands. This AD 
requires replacing the HPC exit inner and outer brush seal packs with 
new brush seal packs, or replacing the HPC exit brush seal assembly 
with a new HPC exit brush seal assembly. This AD results from a report 
of oil leaking into the high pressure turbine (HPT) interstage cavity 
and igniting, leading to an engine case penetration and engine in-
flight shutdown. Although liberated engine parts did not penetrate the 
engine nacelle, we are issuing this AD to prevent uncontained engine 
failure, damage to the airplane, and injury to passengers.

DATES: This AD becomes effective September 27, 2006. The Director of 
the Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of September 27, 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 airworthiness directive (AD). The proposed AD applies 
to Pratt & Whitney (PW) PW4077D, PW4084D, PW4090, and PW4090-3 turbofan 
engines that were reassembled with certain previously used HPC exit 
brush seal assembly parts and certain new or refurbished HPC exit 
diffuser air seal

[[Page 49336]]

inner lands. We published the proposed AD in the Federal Register on 
April 19, 2006 (71 FR 20042). That action proposed to require replacing 
the HPC exit inner and outer brush seal packs with new brush seal 
packs, or replacing the HPC exit brush seal assembly with a new HPC 
exit brush seal assembly.

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, 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 More Accurately Describe the Unsafe Condition

    The Boeing Company requests that we more accurately describe the 
unsafe condition. They propose that we state the unsafe condition as 
``This AD results from a report of oil leaking into the high pressure 
turbine (HPT) interstage cavity and igniting, leading to an engine case 
penetration and engine in-flight shutdown. Although liberated engine 
parts did not penetrate the engine nacelle, we are proposing this AD to 
prevent uncontained engine failure, damage to the airplane, and injury 
to passengers.''
    We agree and adopted the suggested language.

Request for Clarification

    Japan Airlines requests clarification of the compliance on whether 
``cycles-since-last-overhaul (CSLO)'' applies to the engine's last shop 
visit or if it applies to overhaul of the HPC diffuser assembly only.
    We agree we need to clarify the compliance. The CSLO applies to 
overhaul of the HPC diffuser assembly only. As a result of the comment, 
we reworded compliance paragraphs (g)(1) and (g)(2) to read as follows:
    ``(1) By 3,000 cycles-in-service (CIS) since a used HPC exit inner 
brush seal pack and a new or refurbished HPC exit diffuser air seal 
land were installed in the engine, or by March 31, 2007, whichever 
occurs later; however
    (2) If on March 31, 2007, the used HPC exit inner brush seal pack 
coupled with a new or refurbished HPC exit diffuser air seal inner land 
assembly has not accumulated 3,000 CIS, then by 3,000 CIS, or December 
31, 2008, whichever occurs first.''

Conclusion

    We have 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 previously. 
We have 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 76 PW PW4077D, PW4084D, 
PW4090, and PW4090-3 turbofan engines installed on airplanes of U.S. 
registry. We also estimate that it will take about 9 work-hours per 
engine to perform the parts replacement, and that the average labor 
rate is $80 per work-hour. Required parts will cost about $100,017 per 
engine. Based on these figures, we estimate the total cost of the AD to 
U.S. operators to be $7,656,012.

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:

2006-17-08 Pratt & Whitney: Amendment 39-14729. Docket No. FAA-2006-
24034; Directorate Identifier 2006-NE-05-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective 
September 27, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) PW4077D, PW4084D, 
PW4090, and PW4090-3 turbofan engines that were:
    (1) Reassembled with a previously used high pressure compressor 
(HPC) exit inner brush seal pack, part number (P/N) 50J894-01; and
    (2) Reassembled with a new or refurbished HPC exit diffuser air 
seal inner land, P/N 55H869.
    (d) These engines are installed on, but not limited to, Boeing 
777 airplanes.

Unsafe Condition

    (e) This AD results from a report of oil leaking into the high 
pressure turbine (HPT) interstage cavity and igniting, leading to an 
engine case penetration and engine in-flight shutdown. Although 
liberated engine parts did not penetrate the engine nacelle, we are

[[Page 49337]]

issuing this AD to prevent uncontained engine failure, damage to the 
airplane, and injury to passengers.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed at the following compliance times, unless the actions 
have already been done.
    (g) Replace the HPC exit inner and outer brush seal packs with 
new HPC exit inner and outer brush seal packs, or replace the HPC 
exit brush seal assembly with a new HPC exit brush seal assembly as 
follows:
    (1) By 3,000 cycles-in-service (CIS) since a used HPC exit inner 
brush seal pack and a new or refurbished HPC exit diffuser air seal 
land were installed in the engine, or by March 31, 2007, whichever 
occurs later; however,
    (2) If on March 31, 2007, the used HPC exit inner brush seal 
pack coupled with a new or refurbished HPC exit diffuser air seal 
inner land assembly has not accumulated 3,000 CIS, then by 3,000 
CIS, or December 31, 2008, whichever occurs first.
    (h) Use the Accomplishment Instructions of PW Service Bulletin 
No. PW4G-112-A72-280, Revision 1, dated March 21, 2006, to do the 
inner and outer brush pack replacements.

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.

Related Information

    (j) None.

Material Incorporated by Reference

    (k) You must use Pratt & Whitney Service Bulletin No. PW4G-112-
A72-280, Revision 1, dated March 21, 2006, to perform the 
replacements 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 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 August 14, 2006.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E6-13909 Filed 8-22-06; 8:45 am]
BILLING CODE 4910-13-P

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