[Federal Register Volume 73, Number 137 (Wednesday, July 16, 2008)]
[Rules and Regulations]
[Pages 40715-40719]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-15686]



 ========================================================================
 Rules and Regulations
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains regulatory documents 
 having general applicability and legal effect, most of which are keyed 
 to and codified in the Code of Federal Regulations, which is published 
 under 50 titles pursuant to 44 U.S.C. 1510.
 
 The Code of Federal Regulations is sold by the Superintendent of Documents. 
 Prices of new books are listed in the first FEDERAL REGISTER issue of each 
 week.
 
 ========================================================================
 

  Federal Register / Vol. 73, No. 137 / Wednesday, July 16, 2008 / 
Rules and Regulations  

[[Page 40715]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28058; Directorate Identifier 2007-NE-08-AD; 
Amendment 39-15610; AD 2008-14-15]
RIN 2120-AA64


Airworthiness Directives; International Aero Engines AG (IAE) 
V2500 Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for IAE 
V2500-A1, V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-A5, 
V2533-A5, V2525-D5, and V2528-D5 turbofan engines. This AD requires 
removing certain No. 4 bearing oil system components from service at 
the next shop visit or by an end date determined by the engine model. 
This AD results from instances of oil loss from the No. 4 bearing 
compartment. We are issuing this AD to prevent heat damage to high-
pressure turbine (HPT) and low-pressure turbine (LPT) critical life 
limited hardware such as the HPT stage 1-2 airseal. Damage to the HPT 
stage 1-2 airseal could cause uncontained engine failure and damage to 
the airplane.

DATES: This AD becomes effective August 20, 2008.

ADDRESSES: The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, 
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; telephone (781) 238-7758; 
fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to IAE V2500-A1, V2522-A5, 
V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-A5, V2533-A5, V2525-D5, 
and V2528-D5 turbofan engines. We published the proposed AD in the 
Federal Register on July 9, 2007 (72 FR 37126). That action proposed to 
require removing certain No. 4 bearing oil system components from 
service at the next shop visit or by an end date determined by the 
engine model.

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 AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is provided in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Requests To Change Compliance Schedule

    Three commenters, Air Transport Association, United Airlines, and 
Jet Blue Airways ask that we change the compliance:
     To require removing the parts only when they access the 
No. 4 bearing compartment, or
     For engines that don't require access to the No. 4 bearing 
compartment at the next shop visit, to permit them to defer removing 
the parts to the subsequent shop visit, but not later than June 30, 
2011.
    The commenters state that changing the compliance times will avoid 
an undue burden of forcing every engine visit to access the No. 4 
bearing compartment and will avoid aircraft-on-ground situations due to 
lack of spare parts.
    We don't agree. We developed the compliance requirements to 
maintain an acceptable level of safety for the entire V2500 fleet. 
Revising the compliance requirements will result in having to 
accelerate the program in order to maintain the same level of safety. 
That will most likely have an adverse impact on the fleet, due to 
forcing additional engine removals. The engine manufacturer, IAE, has 
also stated that a sufficient supply of spare parts exists to handle 
incorporation within the compliance requirements of the AD, including 
unexpected shop visit situations. However, operators who have special 
conditions may propose alternate compliance schedules, if they can show 
that the alternate compliance schedules provide an acceptable level of 
safety. We didn't change the AD.

Request To Address Design Deficiencies in the HPT Stage 1-2 Airseal

    One commenter, Jet Blue Airways, asks us to revise the AD to 
address design deficiencies in the HPT Stage 1-2 airseal as a 
contributor to HPT distress, rather than attributing the root cause of 
all HPT Stage 1-2 airseal distress to oil in the turbine. The commenter 
states that one of the reported ``confirmed instances of oil loss'' in 
the turbine is inaccurate. One investigation, which was categorized as 
an ``oil in turbine'' event, revealed no substantive evidence of oil 
loss in the turbine, or thermal oil ignition that could have caused the 
dimensional defects in the HPT Stage 1-2 airseal. It is not beyond 
reasonable speculation that, of the remaining 23 events, some 
percentage was incorrectly stated as related to ``No. 4 bearing 
compartment oil loss.''
    We don't agree. We have been involved in the manufacturer's 
Engineering Investigations for each of the subject ``oil in turbine'' 
(OIT) events, and agree with the manufacturer's conclusions. Due to the 
operating conditions surrounding the No. 4 bearing compartment, it can 
be extremely difficult, following engine operation, to detect either 
evidence of oil loss, or thermo oil ignition. The investigation 
concluded that the HPT Stage 1-2 airseal distress experienced is a 
result of thermo oil ignition and not due to design deficiencies in the 
HPT

[[Page 40716]]

Stage 1-2 airseal. The investigation also concluded that measurement of 
specific HPT Stage 1-2 airseal dimensions is a reliable method of 
determining if oil ignition has occurred. We did not change the AD.

Request To Eliminate the Requirement To Incorporate ``OIT Package 2''

    The same commenter, Jet Blue, asks us to revise the AD to eliminate 
the requirement to incorporate the ``OIT Package 2'' for compliance. 
The ``OIT Package 2'' includes mainly external hardware revisions to 
eliminate ``oil traps'' in the oil scavenge tubes for the No. 4 bearing 
compartment that may adversely impact oil scavenge capability. The 
commenter states ``To our knowledge, no V2527-A5 engine incorporating 
the modification standards of `OIT Package' have been found with the 
reported defects or suspected of No. 4 bearing compartment loss.''
    We don't agree. We have reviewed the results of the Engineering 
Investigation of the No. 4 bearing compartment oil loss events, and 
agree with the manufacturer's conclusions that all hardware identified 
in Tables 1, 2, and 3 of this AD contribute to the root cause of 
insufficient oil scavenging from the No. 4 bearing compartment. We 
didn't change the AD.

Request To Revise the NPRM To State a Significant Economic Impact

    The same commenter, Jet Blue, asks us to revise the AD to state 
that the proposed rule would have a significant economic impact. The 
commenter states that the modification would cost more than $8,000,000 
for its fleet.
    We don't agree. In order for us to categorize an AD as a 
``significant economic impact'' to operators, the total cost of the AD 
must exceed $100,000,000 per year. We based our economic assessment for 
this AD on actual hardware replacement cost (using the manufacturer's 
spare parts pricing), the estimated number of work-hours (at $80 per 
hour) required to comply with the AD, and the estimated number of shop 
visits per year. Based on those figures, we estimate the cost of the 
proposed AD to U.S. operators to be $45,037,165 per year, which is 
below the $100,000,000 threshold criterion. We didn't change the AD.

Request To Incorporate IAE Service Bulletin V2500-ENG-72-0541 Into the 
AD

    The same commenter, Jet Blue Airways, requests that we revise the 
AD to incorporate IAE Service Bulletin (SB) V2500-ENG-72-0541 into the 
AD. The commenter states that tracking all of the individual parts 
listed in the AD, especially from parts that are not serialized, is 
cumbersome and beyond reasonable and customary standards.
    We don't agree. Due to the complexity of the various IAE SBs, we 
determined that it would be clearer to list in the AD, only the parts 
that operators must remove from service. We list IAE SB V2500-ENG-72-
0541 in the Related Information section of the AD. That SB provides 
specific instructions and the current replacement part information. 
Listing only the parts that the operators must remove from service also 
provides operators with increased flexibility for installing other 
approved parts not listed in the IAE SB. However, we have added a 
statement in the Compliance section of the AD that states ``If you have 
accomplished IAE Service Bulletin V2500-ENG-72-0541, Revision 4, dated 
March 12, 2008, you have complied with this AD.''

Request To Correct Certain Information in the AD

    One commenter, IAE, asks us to correct certain information in the 
Compliance section of the AD.
    We agree. We have:
     Corrected the part number (P/N) for the Seal Assembly, No. 
4 Bearing, Front, in Table 2 of the AD, from P/N 2A0853 to P/N 2A2055.
     Deleted P/N 2A0830-01, Tube, Scavenge, No. 4 Bearing Assy, 
from Table 2 of the AD.
     Deleted P/N 2A1949-01, Tube, Scavenge, No. 4 Bearing Assy, 
from Table 2 of the AD.
     Deleted P/N 5R8111, Tube A/O Oil, No. 4 Bearing Scav Dif 
Case to Bif Panel, from Table 2 of the AD.
     Added paragraph (j) for V2525-D5 and V2528-D5 engines 
stating that with HPT stage 1 rotor assembly, P/Ns 2A9521-002 and 
2A9621-002, the stage 1 HPT hub metering plug, P/N 2A3182, does not 
need to be removed.
     Replaced IAE Service Bulletin V2500-ENG-72-0541, Revision 
1, dated February 26, 2007, in the Related Information paragraph, with 
IAE Service Bulletin V2500-ENG-72-0541, Revision 4, dated March 12, 
2008.

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 686 engines installed on 
airplanes of U.S. registry. Of those 686 engines, the operators of 
nineteen V2500-A1 engines, thirty -A5 engines and twenty-one -D5 
engines have already complied with the requirements in this AD.

                                  Costs of Compliance per Year by Engine Model
----------------------------------------------------------------------------------------------------------------
                                                              Number of   Total labor   Total parts
                        Engine model                         engines per    cost per     cost per     Total cost
                                                                 year         year         year        per year
----------------------------------------------------------------------------------------------------------------
V2500-A1...................................................           33     $355,080    $7,230,564   $7,585,644
V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-           142    1,368,880    35,790,816   37,159,696
 A5, V2533-A5..............................................
V2525-D5, V2528-D5.........................................            5       15,400       276,425      291,825
----------------------------------------------------------------------------------------------------------------

    Based on these figures, we estimate the total cost of this AD to 
U.S. operators to be $45,037,165 per year.

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

[[Page 40717]]

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, 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:

2008-14-15 International Aero Engines AG (IAE): Amendment 39-15610. 
Docket No. FAA-2007-28058; Directorate Identifier 2007-NE-08-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective August 
20, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to IAE V2500-A1, V2522-A5, V2524-A5, V2527-
A5, V2527E-A5, V2527M-A5, V2530-A5, V2533-A5, V2525-D5, and V2528-D5 
turbofan engines with a part listed by part number (P/N) in this AD 
installed. These engines are installed on, but not limited to, 
Airbus A319, A320, A321, and McDonnell Douglas MD-90 airplanes.

Unsafe Condition

    (d) This AD results from instances of oil loss from the No. 4 
bearing compartment. We are issuing this AD to prevent heat damage 
to high-pressure turbine (HPT) and low-pressure turbine (LPT) 
critical life limited hardware such as the HPT stage 1-2 airseal. 
Damage to the HPT stage 1-2 airseal could cause uncontained engine 
failure and damage to the airplane.

Compliance

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

V2500-A1 Engines

    (f) For V2500-A1 engines, remove the parts listed by P/N in the 
following Table 1 of this AD at the next shop visit after the 
effective date of this AD but not later than November 30, 2008. The 
ATA chapter reference of the IAE V2500-A1 engine manual (E-V2500-
1IA) contains information on removing the parts.

                                                         Table 1.--V2500-A1 Parts To Be Removed
--------------------------------------------------------------------------------------------------------------------------------------------------------
          ATA chapter reference                         P/N                                                Nomenclature
--------------------------------------------------------------------------------------------------------------------------------------------------------
72-42-20.................................  2A0367-01...................  Tube Assy of, Weep, No. 4 Bearing Outer.
72-42-20.................................  2A2873-01...................  Tube Assy of, Weep, No. 4 Bearing Outer.
72-42-20.................................  2A0830-01...................  Tube, Scavenge, No. 4 Bearing Assy.
72-42-20.................................  2A1949-01...................  Tube, Scavenge, No. 4 Bearing Assy.
72-42-20.................................  2A2028-01...................  Tube, Scavenge, No. 4 Bearing Assy.
72-42-20.................................  2A0830-001..................  Tube, Scavenge, No. 4 Bearing Assy.
72-42-20.................................  2A2274-01...................  Tube, Scavenge, No. 4 Bearing Assy.
72-42-33.................................  2A0853......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A2055......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A2834......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A2930......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A3525......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A3538......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A0851......................  Support Assy, No. 4 Bearing Seal.
72-42-33.................................  2A2833......................  Support, No. 4 Bearing, Seal Assy.
72-42-33.................................  2A3537......................  Support, No. 4 Bearing Seal Assy.
72-42-35.................................  2A0892-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Front.
72-42-35.................................  2A2257-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Front.
72-43-20.................................  2A2056......................  Seal Assy, No. 4 Bearing, Rear.
72-43-20.................................  2A2931......................  Seal Assy, No. 4 Bearing, Rear.
72-43-20.................................  2A3526......................  Seal Assy, No. 4 Bearing, Rear.
72-43-20.................................  2A0847......................  Seal Ring Holder.
72-43-20.................................  2A0891-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-43-20.................................  2A1205-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-43-20.................................  2A3078-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-45-11.................................  2A0594......................  Metering Plug, HPT Hub, Stage 1.
72-45-11.................................  2A1040......................  Metering Plug, HPT Hub, Stage 1.
72-45-11.................................  2A2181......................  Metering Plug, HPT Hub, Stage 1.
72-45-13.................................  2A0884......................  Seal Air, HPT Stage 1.
72-45-13.................................  2A1203......................  Seal Air, HPT Stage 1.
72-45-13.................................  2A0884-001..................  Seal Air, HPT Stage 1.
79-22-49.................................  5R8111......................  Tube A/O Oil--No. 4 Brg Scav Dif Case to Bif Panel.
79-22-49.................................  5R8138......................  Tube A/O Oil--No. 4 Brg Scav Dif Case to Bif Panel.
79-22-49.................................  6A5367......................  Tube A/O Oil--No. 4 Brg Scav Dif Case to Bif Panel.

[[Page 40718]]

 
79-22-49.................................  5A9083......................  Tube A/O Oil--No. 4 Brg Discon to Discon.
79-22-49.................................  5A9084......................  Tube A/O Oil--No. 4 Brg Discon to Scav Valve.
79-22-49.................................  5A8573......................  Tube A/O Oil--Press `T' To Pressure Transducer.
79-23-51.................................  1648MK2.....................  Scavenge Valve.
--------------------------------------------------------------------------------------------------------------------------------------------------------

V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-A5, and 
V2533-A5 Engines

    (g) For V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, 
V2530-A5, and V2533-A5 engines, remove the parts listed by P/N in 
the following Table 2 of this AD at the next shop visit after the 
effective date of this AD but not later than June 30, 2011. The ATA 
chapter reference of the IAE V2500-A5 engine manual (E-V2500-1IA) 
contains information on removing the parts.

                        Table 2.--V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, V2530-A5, and V2533-A5 Parts To Be Removed
--------------------------------------------------------------------------------------------------------------------------------------------------------
          ATA chapter reference                         P/N                                                Nomenclature
--------------------------------------------------------------------------------------------------------------------------------------------------------
72-42-20.................................  2A0367-01...................  Tube Assy of, Weep, No. 4 Bearing Outer.
72-42-20.................................  2A2873-01...................  Tube Assy of, Weep, No. 4 Bearing Outer.
72-42-33.................................  2A2055......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A2834......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A2930......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A3525......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A3538......................  Seal Assy, No. 4 Bearing, Front.
72-42-33.................................  2A0851......................  Support Assy, No. 4 Bearing Seal.
72-42-33.................................  2A2833......................  Support, No. 4 Bearing, Seal Assy.
72-42-33.................................  2A3537......................  Support, No. 4 Bearing Seal Assy.
72-42-35.................................  2A0892-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Front.
72-42-35.................................  2A2257-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Front.
72-43-20.................................  2A2056......................  Seal Assy, No. 4 Bearing, Rear.
72-43-20.................................  2A2931......................  Seal Assy, No. 4 Bearing, Rear.
72-43-20.................................  2A3526......................  Seal Assy, No. 4 Bearing, Rear.
72-43-20.................................  2A0847......................  Seal Ring Holder.
72-43-20.................................  2A0891-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-43-20.................................  2A1205-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-43-20.................................  2A3078-01...................  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-45-11.................................  2A0594......................  Metering Plug, HPT Hub, Stage 1.
72-45-11.................................  2A1040......................  Metering Plug, HPT Hub, Stage 1.
72-45-11.................................  2A2354......................  Metering Plug, HPT Hub, Stage 1.
72-45-11.................................  2A3182......................  Metering Plug, HPT Hub, Stage 1.
72-45-13.................................  2A1352......................  Seal Air, HPT Stage 1.
72-45-13.................................  2A3032......................  Seal Air, HPT Stage 1.
79-22-49.................................  5R8138......................  Tube A/O Oil--No. 4 Brg Scav Dif Case to Bif Panel.
79-22-49.................................  6A5367......................  Tube A/O Oil--No. 4 Brg Scav Dif Case to Bif Panel.
79-22-49.................................  5A9083......................  Tube A/O Oil--No. 4 Brg Discon to Discon.
79-22-49.................................  5A9084......................  Tube A/O Oil--No. 4 Brg Discon to Scav Valve.
79-22-49.................................  5A8573......................  Tube A/O Oil--Press `T' To Pressure Transducer.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (h) For V2522-A5, V2524-A5, V2527-A5, V2527E-A5, V2527M-A5, 
V2530-A5, and V2533-A5 engines with HPT stage 1 rotor assembly, P/Ns 
2A9521-002 and 2A9621-002, the stage 1 HPT hub metering plug, P/N 
2A3182, does not need to be removed.

V2525-D5 and V2528-D5 Engines

    (i) For V2525-D5 and V2528-D5 engines, remove the parts listed 
by P/N in the following Table 3 of this AD at the next shop visit 
after the effective date of this AD but not later than June 30, 
2011. The ATA chapter reference of the IAE V2500-D5 engine manual 
(E-V2500-3IA) contains information on removing the parts.

                               Table 3.--V2525-D5 and V2528-D5 Parts To Be Removed
----------------------------------------------------------------------------------------------------------------
     ATA chapter reference             P/N                                  Nomenclature
----------------------------------------------------------------------------------------------------------------
72-42-20......................  2A0367-01........  Tube Assy of, Weep, No. 4 Bearing Outer.
72-42-20......................  2A2873-01........  Tube Assy of, Weep, No. 4 Bearing Outer.
72-42-33......................  2A0851...........  Support Assy, No. 4 Bearing Seal.
72-42-33......................  2A2833...........  Support, No. 4 Bearing, Seal Assy.
72-42-33......................  2A3537...........  Support, No. 4 Bearing Seal Assy.
72-42-33......................  2A2834...........  Seal Assy, No. 4 Bearing, Front.
72-42-33......................  2A2930...........  Seal Assy, No. 4 Bearing, Front.
72-42-33......................  2A3525...........  Seal Assy, No. 4 Bearing, Front.
72-42-33......................  2A3538...........  Seal Assy, No. 4 Bearing, Front.
72-42-35......................  2A2257-01........  Duct Assy, Cooling Air, No. 4 Bearing, Front.

[[Page 40719]]

 
72-43-20......................  2A2056...........  Seal Assy, No. 4 Bearing, Rear.
72-43-20......................  2A2931...........  Seal Assy, No. 4 Bearing, Rear.
72-43-20......................  2A3526...........  Seal Assy, No. 4 Bearing, Rear.
72-43-20......................  2A0847...........  Seal Ring Holder.
72-43-20......................  2A1205-01........  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-43-20......................  2A3078-01........  Duct Assy, Cooling Air, No. 4 Bearing, Rear.
72-45-11......................  2A3182...........  Metering Plug, HPT Hub, Stage 1.
72-45-11......................  2A2354...........  Metering Plug, HPT Hub, Stage 1.
72-45-13......................  2A1352...........  Seal Air, HPT Stage 1.
72-45-13......................  2A3032...........  Seal Air, HPT Stage 1.
----------------------------------------------------------------------------------------------------------------

    (j) For V2525-D5 and V2528-D5 engines with HPT stage 1 rotor 
assembly, P/Ns 2A9521-002 and 2A9621-002, the stage 1 HPT hub 
metering plug, P/N 2A3182, does not need to be removed.

Previous Credit

    (k) If you have accomplished IAE Service Bulletin V2500-ENG-72-
0541, Revision 4, dated March 12, 2008, you have complied with this 
AD.
    (l) After the effective date of this AD, do not install any part 
that has a P/N listed in this AD.

Alternative Methods of Compliance

    (m) 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

    (n) International Aero Engines Service Bulletin No. V2500-ENG-
72-0541, Revision 4, dated March 12, 2008, pertains to the subject 
of this AD.
    (o) Contact Mark Riley, Aerospace Engineer, Engine Certification 
Office, FAA, Engine and Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; telephone (781) 238-7758; fax 
(781) 238-7199, for more information about this AD.

Material Incorporated by Reference

    (p) None.

    Issued in Burlington, Massachusetts, on July 2, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-15686 Filed 7-15-08; 8:45 am]
BILLING CODE 4910-13-P