[Federal Register Volume 67, Number 141 (Tuesday, July 23, 2002)]
[Proposed Rules]
[Pages 48059-48064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-18332]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NE-47-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt and Whitney PW4000 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The Federal Aviation Administration (FAA) proposes to 
supersede an existing airworthiness directive (AD), that is applicable 
to Pratt and Whitney (PW) model PW4000 series turbofan engines. That AD 
currently requires the number of PW4000 engines with potentially 
reduced stability margin to be limited to no more than one engine on 
each airplane, and removing engines that exceed high pressure 
compressor (HPC) cycles-since-overhaul (CSO) or cycles-since-new (CSN) 
from service based on the engine's configuration and category. That AD 
also requires establishing a minimum build standard for engines that 
are returned to service, and performing cool-engine fuel spike testing 
(Testing-21) on engines to be returned to service after having exceeded 
HPC cyclic limits or after shop maintenance.
    This proposal would establish requirements similar to those in the 
existing AD, and would introduce a rules-based criterion to determine 
the engine category classification for engines installed on Airbus A300 
airplanes. This proposal would also add new requirements to manage the 
engine configurations installed on Boeing 747 airplanes, and would 
require repetitive Testing-21 to be performed on certain configuration 
engines. This proposal would also establish criteria which would 
require Testing-21 on certain engines with Phase 0 or Phase 1, FB2T or 
FB2B fan blade configurations. In addition, this proposal would re-
establish high pressure compressor (HPC)-to-high pressure turbine (HPT) 
cycles-since-overhaul (CSO) cyclic mismatch criteria, and add criteria 
to address engine installation changes, engine transfers, and thrust 
rating changes. Also, this proposal would establish criteria to allow 
engine stagger without performing Testing-21 for engines over their 
respective limits. This proposal is prompted by investigation and 
evaluation of PW4000 series turbofan engines surge data, and continuing 
reports of surges in the PW4000 fleet. The actions specified by this AD 
are intended to prevent engine takeoff power losses due to HPC surge.

DATES: Comments must be received by August 22, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2000-NE-47-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by appointment, between 8:00 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. Comments may also be sent via 
the Internet using the following address: ``[email protected]''. 
Comments sent via the Internet must contain the docket number in the 
subject line.
    The service information referenced in the proposed rule may be 
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108, 
telephone (860) 565-6600; fax (860) 565-4503. This information may be 
examined, by appointment, at the FAA, New England Region, Office of the 
Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Diane Cook, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park; telephone (781) 238-7133; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NE-47-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 2000-NE-47-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On December 12, 2001, the Federal Aviation Administration (FAA) 
issued AD 2001-25-11, Amendment 39-12564 (67 FR 1, January 2, 2002) 
which applies to PW model PW4000 series turbofan engines. That AD was 
issued as an interim action to address the engine takeoff power loss 
events while investigation continued. AD 2001-25-11 requires:
     Limiting the number of engines with the HPC cut-back 
stator (CBS) configuration to one on each airplane before further 
flight after the effective date of that AD.
     Limiting the number of PW4000 engines with potentially 
reduced stability margin, to no more than one engine on each airplane.

[[Page 48060]]

     Removing engines that exceed HPC cycles-since-overhaul or 
cycles-since-new (CSN) from service based on the engine's 
configuration.
     Performing a cool-engine fuel spike test (Testing-21) on 
engines that experience a certain type of surge.
     Establishing a minimum build standard for engines that are 
returned to service.
     Performing Testing-21 on engines to be returned to service 
after having exceeded HPC cyclic limits or after shop maintenance.
     AD 2001-25-11 also establishes reporting requirements for 
Testing-21 data. That AD was prompted by reports of surges during 
takeoff on airplanes equipped with PW4000 series turbofan engines.
    Based on continued investigation and evaluation of the PW4000 HPC 
surge data, the field management plan has been refined to better 
address engine takeoff surges and minimize the risk of dual engine 
surges. The FAA has also reviewed the comments received in response to 
AD 2001-25-11. This proposal would require similar requirements as 
compared to AD 2001-25-11, and would also:
     Use a rules-based criterion to determine the engine 
category classification for engines installed on Airbus A300 airplanes 
instead of the list of engine serial numbers used in AD 2001-25-11.
     Add new requirements to manage the engine configurations 
installed on Boeing 747 airplanes. This engine and airplane combination 
would allow, for certain engine configurations, one of the four 
installed engines to remain on-wing until the HPC has accumulated up to 
2,600 CSN or CSO before Testing-21 or an HPC overhaul is required.
     Require configuration F engines to repeat Testing-21 every 
800 HPC cycles since passing Testing-21 (CST).
     Establish criteria, based on the requirements of AD 2001-
01-10, AD 2001-09-05, and AD 2001-09-10, which would require Testing-21 
on engines with Phase 0 or Phase 1, FB2T or FB2B fan blade 
configurations.
     Re-establish the HPC-to-HPT CSO cyclic mismatch criteria 
and would add new criteria to address engine installation changes, 
engine transfers, and thrust rating changes.
     Establish criteria to allow an engine to be removed from 
service and reinstalled on an airplane, without requiring Testing 21, 
if this engine is the unmanaged engine for that airplane.
    The actions specified by the proposed AD are intended to prevent 
engine takeoff power losses due to HPC surge.

Manufacturer's Service Information

    The FAA has reviewed and approved the technical contents of the 
following Pratt & Whitney service information:
     Service Bulletin PW4ENG72-714, Revision 1, dated November 
8, 2001.
     Internal Engineering Notice IEN 96KC973D, dated October 
12, 2001.
     Temporary Revision (TR) TR 71-0018, dated November 14, 
2001.
     TR 71-0026, dated November 14, 2001.
     TR 71 71-0035, dated November 14, 2001.
     Cleaning, Inspection, and Repair (CIR) procedure CIR 
51A357, Section 72-35-68, Inspection/Check-04, Indexes 8-11, dated 
September 15, 2001.
     CIR 51A357, Section 72-35-68, Repair 16, dated June 15, 
1996.
     PW4000 PW engine manual (EM) 50A443, 71-00-00, TESTING-21, 
dated November 14, 2001.
     PW4000 PW EM 50A822, 71-00-00, TESTING-21, dated November 
14, 2001.
     PW 4000 PW EM 50A605, 71-00-00, TESTING-21, dated November 
14, 2001.
    This service information describes procedures for inspections 
required by the proposed AD.

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Pratt & Whitney PW4000 series turbofan 
engines of this same type design, the proposed AD would be issued to 
prevent engine takeoff power losses due to HPC surges, and would 
supersede AD 2001-25-11 to require:
     Establishing requirements similar to those in the existing 
AD, and use of a rules-based criterion to determine the engine category 
classification for engines installed on Airbus A300 airplanes.
     Adding new requirements to manage the engine 
configurations installed on Boeing 747 airplanes. This engine and 
airplane combination would allow, for certain engine configurations, 
one of the four installed engines to remain on-wing until the HPC has 
accumulated up to 2,600 CSN or CSO before Testing-21 or until an HPC 
overhaul is required.
     Configuration F engines to repeat Testing-21 every 800 
CST.
     Establishing criteria which would require Testing-21 on 
engines with Phase 0 or Phase 1, FB2T or FB2B fan blade configurations 
complying with the requirements of AD 2001-09-05, (66 FR 22908, May 7, 
2001); AD 2001-09-10, (66 FR 21853, May 2, 2001), or AD 2001-01-10, (66 
FR 6449, January 22, 2001).
     Re-establishing HPC-to-HPT CSO cyclic mismatch criteria.
     Establishing criteria to address engine installation 
changes, engine transfers, and thrust rating changes.
     Establishing criteria to allow an engine to be removed 
from service and reinstalled on an airplane, without requiring Testing-
21, if this engine is the unmanaged engine for that airplane.
    The actions are required to be done in accordance with the service 
information described previously. This proposal has been coordinated 
with the Transport Airplane Directorate.

Economic Analysis

    There are approximately 2,100 engines of the affected design in the 
worldwide fleet. The FAA estimates that 625 engines installed on 
airplanes of U.S. registry would be affected by this proposed AD. The 
FAA also estimates that, on average, approximately 100 test cell 
stability tests and 36 HPC overhauls will be required annually. It is 
estimated that the cost to industry of a test cell stability test will 
average $15,000 and an HPC overhaul will cost approximately $400,000. 
Based on these figures, the total average annual cost of the proposed 
AD to U.S. operators is estimated to be $15,900,000.

Regulatory Analysis

    This proposed rule does not have federalism implications, as 
defined in Executive Order 13132, because it 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. 
Accordingly, the FAA has not consulted with state authorities prior to 
publication of this proposed rule.
    For the reasons discussed above, I certify that 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 Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

[[Page 48061]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by removing Amendment 39-12564, (67 FR 
1, January 2, 2002), and by adding a new airworthiness directive:

Pratt & Whitney: Docket No. 2000-NE-47-AD. Supersedes AD 2001-25-11, 
Amendment 39-12564.

Applicability

    This airworthiness directive (AD) is applicable to Pratt and 
Whitney (PW) model PW4050, PW4052, PW4056, PW4060, PW4060A, PW4060C, 
PW4062, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4460, PW4462, and 
PW4650 turbofan engines. These engines are installed on, but not 
limited to, certain models of Airbus Industrie A300, Airbus 
Industrie A310, Boeing 747, Boeing 767, and McDonnell Douglas MD-11 
series airplanes.

    Note 1: This AD applies to each engine identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For engines that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (t) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

Compliance

    Compliance with this AD is required as indicated, unless already 
done.
    To prevent engine takeoff power losses due to HPC surges, do the 
following:
    (a) When complying with this AD, determine the configuration of 
each engine on each airplane using the following Table 1:

                 Table 1.--Engine Configuration Listing
------------------------------------------------------------------------
                         Configuration
   Configuration           Designator                Description
------------------------------------------------------------------------
(1) Phase 1 without  A                      Engines that did not
 high pressure                               incorporate the Phase 3
 turbine (HPT) 1st                           configuration at the time
 turbine vane cut                            they were originally
 back (1TVCB)                                manufactured, or have not
                                             been converted to Phase 3
                                             configuration; and have not
                                             incorporated HPT 1TVCB
                                             using any revision of
                                             service bulletin (SB)
                                             PW4ENG 72-514.
------------------------------------------------------------------------
(2) Phase 1 with     B                      Same as configuration
 1TVCB                                       designator (A) except that
                                             HPT 1TVCB has been
                                             incorporated using any
                                             revision of SB PW4ENG 72-
                                             514.
------------------------------------------------------------------------
(3) Phase 3, 2nd     C                      Engines that incorporated
 Run                                         the Phase 3 configuration
                                             at the time they were
                                             originally manufactured, or
                                             have been converted to the
                                             Phase 3 configuration
                                             during service; and that
                                             have had at least one high
                                             pressure compressor (HPC)
                                             overhaul since new.
------------------------------------------------------------------------
(4) Phase 3, 1st     D                      Same as configuration
 Run                                         designator (C) except that
                                             the engine has not had an
                                             HPC overhaul since new.
------------------------------------------------------------------------
(5) HPC Cutback      E                      Engines that currently
 Stator                                      incorporate any revision of
 Configuration                               SB's PW4ENG72-706, PW4ENG72-
 Engines                                     704, or PW4ENG72-711.
------------------------------------------------------------------------
(6) Engines that     F                      Engines which have
 have passed                                 successfully passed that
 Testing-21                                  have passed Testing-21
                                             performed in accordance
                                             with paragraph (h) of this
                                             AD. Once an engine has
                                             passed a Testing-21, it
                                             will remain a Configuration
                                             F engine until the HPC is
                                             overhauled, or is replaced
                                             with a new or overhauled
                                             HPC.
------------------------------------------------------------------------

Engines Installed on Boeing 767 and MD-11 Airplanes

    (b) For engines installed on Boeing 767 and MD-11 airplanes, 
except as provided in paragraph (c) of this AD, within 50 airplane 
cycles after the effective date of this AD, limit the number of 
engines that exceed the HPC cycles-since-new (CSN), HPC cycles-
since-overhaul (CSO), or HPC cycles since passing Testing-21 (CST) 
limits listed in the following Table 2, to not more than one engine 
per airplane. Thereafter, ensure that no more than one engine per 
airplane exceeds the HPC CSN, CSO, or CST limit listed in Table 2 of 
this AD. See paragraph (h) of this AD for return to service 
requirements.

Table 2 follows:

[[Page 48062]]



                              Table 2.--Engine Stagger Limits for Boeing Airplanes
----------------------------------------------------------------------------------------------------------------
                                                                                B767--PW4060,
    Configuration        B747--PW4056       B767--PW4052      B767--PW4056        PW4060A,       MD-11, PW4460,
     designator                                                                PW4060C, PW4062       PW4462
----------------------------------------------------------------------------------------------------------------
A...................  1,400 CSN or CSO   3,000 CSN or CSO.  1,600 CSN or CSO  900 CSN or CSO..  800 CSN or CSO.
----------------------------------------------------------------------------------------------------------------
B...................  2,100 CSN or CSO   4,400 CSN or CSO.  2,800 CSN or CSO  2,000 CSN or CSO  1,200 CSN or
                                                                                                 CSO.
----------------------------------------------------------------------------------------------------------------
C...................  2,100 CSO          4,400 CSO          2,800 CSO         2,000 CSO         1,300 CSO.
----------------------------------------------------------------------------------------------------------------
D...................  2,600 CSN........  4,400 CSN          3,000 CSN         2,200 CSN         2,000 CSN.
----------------------------------------------------------------------------------------------------------------
E...................  750 CSN or CSO     750 CSN or CSO     750 CSN or CSO..  750 CSN or CSO..  750 CSN or CSO.
----------------------------------------------------------------------------------------------------------------
F...................  800 CST..........  800 CST            800 CST           800 CST           800 CST.
----------------------------------------------------------------------------------------------------------------

Configuration E Engines Installed on Boeing 747, 767, and MD-11 
Airplanes

    (c) For configuration E engines, do the following:
    (1) Before further flight, limit the number of engines with 
configuration E as described in Table 1 of this AD, to one on each 
airplane.
    (2) Remove all engines with configuration E from service before 
accumulating 1,300 CSN or cycles-since-conversion to configuration 
E, whichever is later.

Engines Installed on Boeing 747 Airplanes

    (d) Except as provided in paragraph (c) of this AD, within 50 
airplane cycles after the effective date of this AD, and thereafter, 
manage the engine configurations installed on Boeing 747 airplanes 
as follows:
    (1) Limit the number of configuration A, B, C, or E engines that 
exceed the HPC CSN or HPC CSO limits listed in Table 2 of this AD, 
to not more than one engine per airplane.
    (2) The one configuration A, B, C, or E engine per airplane that 
exceeds the HPC CSN or CSO limits listed in Table 2 of this AD, must 
be limited to 2,600 HPC CSN or CSO for configuration A, B or C 
engines, or 1,300 HPC CSN or cycles-since-conversion to 
configuration E, whichever is later, for configuration E engines.
    (3) Remove from service configuration D engines before 
accumulating 2,600 CSN.
    (4) Remove from service configuration F engines before 
accumulating 800 CST.
    (5) Configuration A, B, C, D, and F engines may be returned to 
service after completing paragraph (h) of this AD.

Engines Installed on Airbus A300 and A310 Airplanes

    (e) Use the following paragraphs (e)(1) through (e)(9) to 
determine which Airbus A300 PW4158 engine category 1, 2, or 3 limits 
of the following Table 3 of this AD apply to your engine fleet:

          Table 3.--Engine Stagger Limits for Airbus Airplanes
------------------------------------------------------------------------
                        A300 PW4158    A300 PW4158 A300
   Configuration      category 1, and   PW4158 category    A300 PW4158
     designator       A310 PW4156 and     2, and A310       category 3
                          PW4156A           PW4152
------------------------------------------------------------------------
A..................  900 CSN or CSO..  1,850 CSN or CSO  500 CSN or CSO.
------------------------------------------------------------------------
B..................  2,200 CSN or CSO  4,400 CSN or CSO  1,600 CSN or
                                                          CSO.
------------------------------------------------------------------------
C..................  2,200 CSO.......  4,400 CSO.......  1,600 CSO.
------------------------------------------------------------------------
D..................  4,400 CSN.......  4,400 CSN.......  4,400 CSN.
------------------------------------------------------------------------
E..................  Not Applicable..  Not Applicable..  Not Applicable.
------------------------------------------------------------------------
F..................  800 CST.........  800 CST.........  800 CST.
------------------------------------------------------------------------

    (1) Determine the number of Group 3 takeoff surges experienced 
by engines in your fleet before April 13, 2001. Count surge events 
for engines that had an HPC overhaul and incorporated either SB PW 
4ENG 72-484 or SB PW4ENG 72-575 at the time of overhaul. Do not 
count surge events for engines that did not have the HPC overhauled 
(i.e. 1st run engine) or had the HPC overhauled but did not 
incorporate either SB PW4ENG 72-484 or SB PW4ENG 72-575. See 
paragraph (s)(5) of this AD for a definition of a Group 3 takeoff 
surge.
    (2) Determine the number of cumulative HPC CSO accrued by 
engines in your fleet before April 13, 2001. Count HPC CSO for 
engines that had an HPC overhaul and incorporated either SB PW4ENG 
72-484 or SB PW4ENG 72-575 at the time of overhaul. Do not count HPC 
CSO accrued on your engines while operating outside your fleet.
    (3) Calculate the surge rate by dividing the number of Group 3 
takeoff surges determined in paragraph (e)(1) of this AD, by the 
number of cumulative HPC CSO determined in paragraph (e)(2) of this 
AD, and then multiply by 1,000.
    (4) If the surge rate calculated in paragraph (e)(3) of this AD 
is less than 0.005, go to paragraph (e)(5) of this AD. If the surge 
rate calculated in paragraph (e)(3) of this AD is greater than or 
equal to 0.005, go to paragraph (e)(6) of this AD.
    (5) If the cumulative HPC CSO determined in paragraph (e)(2) of 
this AD is greater than or equal to 200,000 cycles, use A300 PW4158 
Category 2 limits of Table 3 of this AD. If less than 200,000 
cycles, go to paragraph (e)(7) of this AD.
    (6) If the surge rate calculated in paragraph (e)(3) of this AD 
is greater than 0.035, use A300 PW 4158 Category 3 limits of Table 3 
of this AD. If less than or equal to 0.035, go to paragraph (e)(7) 
of this AD.
    (7) Determine the percent of takeoffs with greater than a 1.45 
Takeoff engine pressure ratio (EPR) data for engines operating in 
your

[[Page 48063]]

fleet. Count takeoffs from a random sample of at least 700 airplane 
takeoffs that has occurred over at least a 3-month time period, for 
a period beginning no earlier than 23 months prior to the effective 
date of this AD. See paragraph (s)(6) of this AD for definition of 
Takeoff EPR data.
    (8) If there is insufficient data to satisfy the criteria of 
paragraph (e)(7) of this AD, use A300 PW4158 Category 3 limits of 
Table 3 of this AD.
    (9) If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (e)(7) of this AD is 
greater than 27%, use A300 PW 4158 Category 3 limits listed in Table 
3 of this AD. If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (e)(7) of this AD is less 
than or equal to 27%, use A300 PW 4158 Category 1 limits listed in 
Table 3 of this AD.
    (f) For engines installed on Airbus A300 or A310 airplanes, 
within 50 airplane cycles after the effective date of this AD, limit 
the number of engines that exceed the CSN, CSO, or CST limits listed 
in Table 3 of this AD, to no more than one engine per airplane. 
Thereafter, ensure that no more than one engine per airplane exceeds 
the HPC CSN, CSO, or CST limits listed in Table 3 of this AD. See 
paragraph (h) of this AD for return to service requirements.
    (g) For Airbus A300 PW4158 engine operators, except those 
operators whose engine fleets are determined to be Category 3 
classification based on surge rate in accordance with paragraph 
(e)(6) of this AD, re-evaluate your fleet category within 6 months 
from the effective date of this AD, and thereafter, at intervals not 
to exceed 6 months, using the following criteria:
    (1) For operators whose engine fleets are initially classified 
as Category 1 or 3 in accordance with paragraph (e) of this AD, 
determine the percent of takeoffs with greater than a 1.45 Takeoff 
EPR data for engines operating in your fleet. Count takeoffs from a 
sample of at least 200 takeoffs that occurred over the most recent 
six month time period since the last categorization was determined, 
or the total number of takeoffs accumulated over 6 months if less 
than 200 takeoffs. See paragraph (s)(6) of this AD for definition of 
takeoff EPR data.
    (i) If there is insufficient data to satisfy the criteria of 
paragraph (g)(1) of this AD, use A300 PW4158 Category 3 limits 
listed in Table 3 of this AD.
    (ii) If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (g)(1) of this AD is 
greater than 27%, use A300 PW4158 Category 3 limits listed in Table 
3 of this AD.
    (iii) If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (g)(1) of this AD is less 
than or equal to 27%, use A300 PW4158 Category 1 limits listed in 
Table 3 of this AD.
    (2) For operators whose engine fleets are initially classified 
as Category 2 in accordance with paragraph (e) of this AD, determine 
the percent of takeoffs with greater than a 1.45 Takeoff EPR data 
for engines operating in your fleet. Count takeoffs from a sample of 
at least 200 takeoffs that occurred over the most recent six month 
time period since the last categorization was determined, or the 
total number of takeoffs accumulated over 6 months if less than 200 
takeoffs. See paragraph (s)(6) of this AD for definition of takeoff 
EPR data.
    (i) If there is insufficient data to satisfy the criteria of 
paragraph (g)(1) of this AD, use A300 PW4158 Category 3 limits 
listed in Table 3 of this AD.
    (ii) If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (g)(1) of this AD is 
greater than 37%, use A300 PW4158 Category 3 limits listed in Table 
3 of this AD.
    (iii) If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (g)(1) of this AD is 
greater than or equal to 13% and less than or equal to 37%, use A300 
PW4158 Category 1 limits listed in Table 3 of this AD.
    (iv) If the percentage of takeoffs with greater than a 1.45 
Takeoff EPR data determined in paragraph (g)(1) of this AD is less 
than 13%, use A300 PW4158 Category 2 limits listed in Table 3 of 
this AD.

Return To Service Requirements for All Engines

    (h) Engines removed from service in accordance with paragraph 
(b), (d), or (f) of this AD may be returned to service under the 
following conditions:
    (1) After passing a cool-engine fuel spike stability test 
(Testing-21) that has been done in accordance with one of the 
following PW4000 Engine Manuals (EM) as applicable, except for 
engines configured with Configuration E, or engines that have 
experienced a Group 3 takeoff surge:
    (i) PW4000 PW EM 50A443, 71-00-00, TESTING-21, dated November 
14, 2001.
    (ii) PW4000 PW EM 50A822, 71-00-00, TESTING-21, dated November 
14, 2001.
    (iii) PW 4000 PW EM 50A605, 71-00-00, TESTING-21, dated November 
14, 2001; or
    (2) Engines tested before the effective date of this AD, in 
accordance with any of the following PW4000 EM Temporary Revisions, 
meet the requirements of Testing-21:
    (i) PW4000 EM 50A443, Temporary Revision No. 71-0026, dated 
November 14, 2001.
    (ii) PW4000 EM50A822, Temporary Revision No. 71-0018, dated 
November 14, 2001.
    (iii) PW4000 EM50A605, Temporary Revision No. 71-0035, dated 
November 14, 2001; or
    (3) Engines tested before the effective date of this AD, in 
accordance with PW IEN 96KC973D, dated October 12, 2001, meet the 
requirements of Testing-21; or
    (4) The engine HPC was replaced with an HPC that is new from 
production with no time in service; or
    (5) The engine HPC has been overhauled, or the engine HPC 
replaced with an overhauled HPC with zero cycles since overhaul; or
    (6) An engine that is either below or exceeding the limits of 
Table 2 or Table 3 of this AD may be removed and installed on 
another airplane without Testing-21 as long as the requirements of 
paragraph (b), (d) or (f) AD are met at the time of engine 
installation.

Phase 0 or Phase 1, FB2T or FB2B Fan Blade Configurations

    (i) For engines with Phase 0 or Phase 1, FB2T or FB2B fan blade 
configurations complying with the requirements of AD 2001-09-05, (66 
FR 22908, May 5, 2001), AD 2001-09-10, (66 FR 21853, May 2, 2001), 
or AD 2001-01-10, (66 FR 6449, January 22, 2001), do the following:
    (1) Operators complying with the AD's listed in paragraph (i) of 
this AD using the weight restriction compliance method, must perform 
Testing-21 in accordance with paragraph (h)(1) of this AD whenever 
any quantity of fan blades are replaced with new fan blades, 
overhauled fan blades, or with fan blades having the leading edges 
recontoured after the effective date of this AD, if during the shop 
visit the HPC is not overhauled and separation of a major engine 
flange, located between ``A'' flange and ``T'' flange, does not 
occur.
    (2) Testing-21 in accordance with paragraph (h)(1) of this AD is 
required if an operator changes from the weight restriction 
compliance method to the fan blade leading edge recontouring method, 
each time fan blade leading edge recontouring is done after the 
effective date of this AD, if the fan blades accumulate more than 
450 cycles since new or since fan blade overhaul, or since the last 
time the fan blade leading edges were recontoured.

Minimum Build Standard

    (j) After the effective date of this AD, do not install an 
engine with HPC and HPT modules where the CSO of the HPC is 1,500 
cycles or greater than the CSN or CSO of the HPT.
    (k) For any engine that undergoes an HPC overhaul after the 
effective date of this AD, do the following:
    (1) Inspect the HPC mid hook and rear hook of the HPC inner case 
for wear in accordance with PW4000 Clean, Inspect and Repair (CIR) 
Manual PN 51A357, Section 72-35-68 Inspection/Check-04, Indexes 8-
11, dated September 15, 2001. If the HPC rear hook is worn beyond 
serviceable limits, replace the HPC inner case rear hook with an 
improved durability hook in accordance with PW SB PW4ENG72-714, 
Revision 1, dated November 8, 2001, or Chromalloy Florida Repair 
Procedure 00-CFL-039-0. If the HPC inner case mid hook is worn 
beyond serviceable limits, repair the HPC inner case mid hook in 
accordance with PW4000 CIR PN 51A357 Section 72-35-68, Repair-16.
    (2) After the effective date of this AD, any engine that 
undergoes an HPC overhaul may not be returned to service unless it 
meets the build standard of PW SB PW4ENG 72-484, PW4ENG 72-486, 
PW4ENG 72-514, and PW4ENG 72-575. Engines that incorporate the Phase 
3 configuration already meet the build standard defined by PW SB 
PW4ENG 72-514.
    (l) After the effective date of this AD, any engine that 
undergoes separation of the HPC and HPT modules must not be 
installed on an airplane unless it meets the build standard of PW SB 
PW4ENG 72-514. Engines that incorporate the Phase 3 configuration 
already meet the build standard defined by PW SB PW4ENG 72-514.

[[Page 48064]]

Stability Testing Requirements

    (m) After the effective date of this AD, Testing-21 must be 
performed in accordance with paragraph (h)(1) of this AD, before an 
engine can be returned to service after having undergone maintenance 
in the shop, except under any of the following conditions:
    (1) The engine HPC was overhauled, or replaced with an 
overhauled HPC with zero cycles since overhaul; or
    (2) The engine HPC was replaced with an HPC that is new from 
production with no time in service; or
    (3) The shop visit did not result in the separation of a major 
engine flange located between ``A'' flange and ``T'' flange.

Thrust Rating Changes, Installation Changes, and Engine Transfers

    (n) When a thrust rating change has been made by using the 
Electronic Engine Control (EEC) programming plug, or an installation 
change has been made during an HPC overhaul period, use the lowest 
cyclic limit of Table 2 or Table 3 of this AD, associated with any 
engine thrust rating change or with any installation change made 
during the affected HPC overhaul period. See paragraph (s)(2) for 
definition of HPC overhaul period.
    (o) When a PW4158 engine is transferred to another PW4158 engine 
operator whose engine fleet has a different category, use the lowest 
cyclic limit in Table 3 of this AD that was used or will be used 
during the affected HPC overhaul period.
    (p) When a PW 4158 engine operator whose engine fleet changes 
category in accordance with paragraph (g) of this AD, use the lowest 
cyclic limits in Table 3 of this AD that were used during the 
affected HPC overhaul period.
    (q) Engines with an HPC having zero CSN or CSO at the time of 
thrust rating change, or installation change, or engine transfer 
between PW4158 engine operators, or subsequent change in operator 
engine fleet category in accordance with paragraph (g) of this AD in 
the direction of lower to higher Table 3 limits, are exempt from the 
lowest cyclic limit requirement in paragraphs (n), (o), and (p) of 
this AD.

Engines That Surge

    (r) For engines that experience a surge, and after 
troubleshooting procedures are completed for airplane-level surge 
during forward or reverse thrust, do the following:
    (1) For engines that experience a Group 3 takeoff surge, remove 
the engine from service before further flight and perform an HPC 
overhaul.
    (2) For any engine that experiences a forward or reverse thrust 
surge at EPR's greater than 1.25 that is not a Group 3 takeoff 
surge, do the following:
    (i) For configuration A, B, C, D, and F engines, remove engine 
from service within 25 CIS or before further flight if airplane-
level troubleshooting procedures require immediate engine removal, 
and perform Testing-21 in accordance with paragraph (h)(1) of this 
AD.
    (ii) For configuration E engines, remove engine from service 
within 25 CIS or before further flight if airplane-level 
troubleshooting procedures require immediate engine removal.

Definitions

    (s) For the purposes of this AD, the following definitions 
apply:
    (1) An HPC overhaul is defined as restoration of the HPC stages 
5 through 15 blade tip clearances to the limits specified in the 
applicable fits and clearances section of the engine manual.
    (2) An HPC overhaul period is defined as the time period between 
HPC overhauls.
    (3) An HPT overhaul is defined as restoration of the HPT stage 1 
and 2 blade tip clearances to the limits specified in the applicable 
fits and clearances section of the engine manual.
    (4) A Phase 3 engine is identified by a (-3) suffix after the 
engine model number on the data plate if incorporated at original 
manufacture, or a ``CN'' suffix after the engine serial number if 
the engine was converted using PW SB's PW4ENG 72-490, PW4ENG 72-504, 
or PW4ENG 72-572 after original manufacture.
    (5) A Group 3 takeoff surge is defined as the occurrence of any 
of the following engine symptoms during an attempted airplane 
takeoff operation (either at reduced, derated or full rated takeoff 
power setting) after takeoff power set, which can be attributed to 
no specific and correctable fault condition after following 
airplane-level surge during forward thrust troubleshooting 
procedures:
    (i) Engine noises, including rumblings and loud ``bang(s).''
    (ii) Unstable engine parameters (EPR, N1, N2, and fuel flow) at 
a fixed thrust setting.
    (iii) Exhaust gas temperature (EGT) increase.
    (iv) Flames from the inlet, the exhaust, or both.
    (6) Takeoff EPR data is defined as Maximum Takeoff EPR if 
takeoff with Takeoff-Go-Around (TOGA) is selected or Flex Takeoff 
EPR if takeoff with Flex Takeoff (FLXTO) is selected. Maximum 
Takeoff EPR or Flex Takeoff EPR may be recorded using any of the 
following methods:
    (i) Manually recorded by the flight crew read from the Takeoff 
EPR power management table during flight preparation (see Aircraft 
Flight Manual (AFM) chapter 5.02.00 and 6.02.01, or Flight Crew 
Operation Manual (FCOM) chapter 2.09.20) and then adjusted by adding 
0.010 to the EPR value recorded; or
    (ii) Automatically recorded during Takeoff at 0.18 Mach Number 
(Mn) (between 0.15 and 0.20 Mn is acceptable) using an aircraft 
automatic data recording system and then adjusted by subtracting 
0.010 from the EPR value recorded; or
    (iii) Automatically recorded during takeoff at maximum EGT, 
which typically occurs at 0.25 `` 0.30 Mn, using an aircraft 
automatic data recording system.

Alternative Methods of Compliance

    (t) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Engine Certification Office (ECO). 
Operators must submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Special Flight Permits

    (u) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be done.

Testing-21 Reports

    (v) Within 60 days of test date, report the results of the cool-
engine fuel spike stability assessment tests (Testing-21) to the 
ANE-142 Branch Manager, Engine Certification Office, 12 New England 
Executive Park, Burlington, MA 01803-5299, or by electronic mail to 
[email protected]. Reporting requirements have been 
approved by the Office of Management and Budget and assigned OMB 
control number 2120-0056. Be sure to include the following 
information:
    (1) Engine serial number.
    (2) Engine configuration designation per Table 1 of this AD.
    (3) Date of the cool-engine fuel spike stability test.
    (4) HPC Serial Number, and HPC time and cycles-since-new and 
since-compressor-overhaul at the time of the test.
    (5) Results of the test (Pass or Fail).

    Issued in Burlington Massachusetts, on July 15, 2002.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 02-18332 Filed 7-22-02; 8:45 am]
BILLING CODE 4910-13-P