[Federal Register Volume 66, Number 82 (Friday, April 27, 2001)]
[Rules and Regulations]
[Pages 21083-21086]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-10463]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-09-AD; Amendment 39-12212; AD 2001-09-07]
RIN 2120-AA64


Airworthiness Directives; Pratt and Whitney PW4000 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule, request for comments.

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SUMMARY: This amendment supersedes an emergency airworthiness directive 
(AD) 2001-08-52 that was sent previously to all known U.S. owners and 
operators of Pratt and Whitney (PW) model PW4050, PW4052, PW4056, 
PW4060, PW4060A, PW4060C, PW4062, PW4152, PW4156, PW4156A, PW4158, 
PW4160, PW4460, PW4462, and PW4650 turbofan engines by individual 
letters. That emergency AD requires limiting the number of PW4000 
engines, listed by serial number (SN) in that AD, with potentially 
reduced stability to no more than one engine on each airplane; removal 
of certain PW4000 engines, listed by SN in this AD, before exceeding 
cyclic limits that are determined by airplane model; removal of certain 
PW4000 engines, listed by SN in this AD, that have a high pressure 
compressor with 1,500 or more cycles-since-overhaul (CSO) greater than 
the high pressure turbine (HPT) CSO; and requires a minimum rebuild 
standard for engines that are returned to service. This amendment 
supersedes emergency AD 2001-08-52 to provide clarifications and 
additions to the compliance and applicability of certain paragraphs of 
AD 2001-08-52. This AD is prompted by a report of a dual-engine surge 
event during take-off on an Airbus Industrie A300 airplane. The actions 
specified by this AD are intended to prevent multiple-engine power 
losses due to high pressure compressor (HPC) surge at a critical phase 
of flight such as takeoff or climb.

DATES: Effective May 14, 2001.
    Comments for inclusion in the Rules Docket must be received on or 
before June 26, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2001-NE-09-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. 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.

FOR FURTHER INFORMATION CONTACT: Peter White, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7128; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On April 13, 2001, the Federal Aviation 
Administration (FAA) issued emergency

[[Page 21084]]

AD 2001-08-52, applicable to PW model PW4050, PW4052, PW4056, PW4060, 
PW4060A, PW4060C, PW4062, PW4152, PW4156, PW4156A, PW4158, PW4160, 
PW4460, PW4462, and PW4650 turbofan engines, which requires:
     Limiting the number of PW4000 engines, listed by serial 
number (SN) in that AD, to no more than one engine with potentially 
reduced stability on each airplane within 10 cycles after receipt of 
that AD. AND
     Removal of certain PW4000 engines, listed by SN in that 
AD, before exceeding cyclic limits that are determined by airplane 
model, or within 100 cycles-in-service (CIS) after the receipt of that 
AD whichever occurs later. AND
     Removal of certain PW4000 engines, listed by SN in that 
AD, within 100 cycles after the receipt of that AD, that have an HPC 
with 1,500 or more CSO greater than the HPT CSO. AND
     A minimum rebuild standard for engines that are returned 
to service. Since AD 2001-08-52 was issued, the FAA has reevaluated 
those requirements, and found that the requirements of that AD need to 
be clarified and changed to meet the original safety intent of the 
emergency AD. This amendment supersedes emergency AD 2001-08-52 to 
provide clarifications and additions to the compliance and 
applicability of certain paragraphs of AD 2001-08-52. Significant 
changes to AD 2001-08-52 include:
     Minor modifications made to engine serial number listings 
in Table 1 and Table 2 of this AD.
     Adding engines with the HPC Cutback Stator (CBS) 
configuration to the installation restrictions of paragraph (c), to be 
consistent with the installation restrictions of paragraph (b) of this 
AD.
     Editing paragraph (f) to clarify applicability to all 
PW4000 series engines defined in the applicability section.
     Modifying paragraph (g) to clarify applicability, and to 
specifically require an HPC overhaul.
     Modifying paragraph (h) to alter applicability to Table 2 
engines only, and to clarify applicability.
     Adding paragraph (i) to clarify requirements for all 
PW4000 engines included in the applicability section of this AD.
     Clarifying the elimination of installation restrictions in 
paragraphs (g) and (h).

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since the unsafe condition described is likely to exist or develop 
on other PW4000 series turbofan engines of the same type design, this 
AD is being issued to prevent multiple-engine power losses due to high 
pressure compressor (HPC) surge at a critical phase of flight such as 
takeoff or climb. This AD requires:
     Limiting the number of PW4000 engines listed by serial 
number (SN) in this AD, to no more than one engine with potentially 
reduced stability on each airplane within 10 cycles after effective 
date of this AD. AND
     Removal of certain PW4000 engines, listed by SN in this 
AD, before exceeding cyclic limits that are determined by airplane 
model, or within 100 cycles-in-service (CIS) after the effective date 
of this AD whichever occurs later. AND
     Removal of certain PW4000 engines, listed by SN in this 
AD, within 100 cycles after the effective date of this AD, that have an 
HPC with 1,500 or more CSO greater than the HPT CSO. AND
     A minimum rebuild standard for engines that are returned 
to service.

Immediate Adoption of This AD

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NE-09-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    This final 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 final rule.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, may 
be obtained from the Rules Docket at the location provided under the 
caption ADDRESSES

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:


[[Page 21085]]


    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

2001-09-07  Pratt and Whitney: Amendment 39-12212. Docket 2001-NE-
09-AD.

    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 Boeing 747, 
Boeing 767, Airbus Industrie A300, Airbus Industrie A310, 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 (k) 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 multiple-engine power losses due to high pressure 
compressor (HPC) surge at a critical phase of flight such as takeoff 
or climb, do the following:
    (a) Within 10 cycles-in-service (CIS) after the effective date 
of this AD, limit the number of engines listed by SN in the 
following Table 1 of this AD, to no more than one per airplane:

               Table 1. Suspected High Surge Rate Engines
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723845, 723934, 723936, 723962, 723966, 723967, 723969, 724012, 724013,
 724016, 724030, 724040, 724041, 724045, 724057, 724073, 724115, 724137,
 724153, 724175, 724195, 724196, 724198, 724200, 724351, 724383, 724501,
 724612, 724615, 724616, 724625, 724629, 724689, 724808, 724827, 724829,
 724830, 724833, 724837, 724838, 724848, 724855, 724857, 724858, 727316,
 727317
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    (b) Engines that are removed in accordance with paragraph (a) of 
this AD may be installed on an airplane if ALL of the following 
conditions are met:
    (1) That airplane does not have any engines with a SN that is 
listed in Table 1 or Table 2 of this AD. AND
    (2) The installed engines meet the requirements of paragraphs 
(d) and (e) of this AD. AND
    (3) The airplane does not have any engines that incorporate the 
HPC Cutback Stator (CBS) configuration, which has been incorporated 
as specified by the following PW service bulletins (SB's) or earlier 
revisions: PW4ENG 72-706, Revision 3, dated July 17, 2000; PW4ENG 
72-711, dated June 13, 2000; or PW4ENG 72-704, dated July 17, 2000.
    (c) After the effective date of this AD, do not install an 
engine with a SN that is listed in the following Table 2 of this AD, 
or an engine incorporating the HPC CBS configuration as defined in 
(b)(3) of this AD, on an airplane that has an engine with a SN that 
is listed in Table 1 of this AD:

 Table 2. Engines Restricted from Installation with Suspected High Surge
                              Rate Engines
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717508, 717710CN, 723859, 723863, 723938, 723963, 724022, 724024,
 724050, 724054, 724080, 724099, 724173, 724179, 724184, 724191, 724205,
 724385, 724386, 724479, 724509, 724566, 724690, 724847, 724861, 724864,
 724870, 724882, 724883, 724893, 727365, 727395, 727421, 727426, 727462,
 727478, 727496, 727500, 727502, 727506, 727521, 727535, 727536, 727537,
 727540, 727543, 727617, 727619, 727747, 733701, (d) Remove engines
 listed by SN in
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    Table 1 of this AD within 100 CIS after the effective date of 
this AD, or before exceeding the cyclic limits listed in the 
following Table 3 of this AD, whichever occurs later:

                           Table 3. High Pressure Compressor Cycle Limits by Airplane
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                      Airplane                                   High pressure compressor (HPC) cycles
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(1) Boeing 767 and 747..............................  2,500 cycles-since-overhaul (CSO).
(2) McDonnell Douglas MD-11.........................  2,500 CSO.
(3) Airbus A300 and A310............................  2,000 CSO.
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    (e) Within 100 CIS after the effective date of this AD, remove 
engines listed by SN in Table 1 of this AD that have an HPC with 
1,500 or more CSO greater than the CSO of the HPT.
    (f) For any engine listed in the applicability of this AD, that 
is inducted into the shop that results in separation of the HPC and 
HPT modules after the effective date of this AD, do not install any 
HPC or HPT modules where the CSO of the HPC will be 1,500 or more 
cycles greater than the CSO of the HPT.
    (g) When engines listed by SN in Table 1 of this AD are removed 
from service in accordance with paragraphs (a), (d), or (e) of this 
AD, they may be returned to service after the accomplishment of an 
HPC overhaul and meeting the requirements of paragraph (h)(1) or 
(h)(2) of this AD without the installation limitations of paragraphs 
(a), (b), (c) and (d) of this AD.
    (h) After the effective date of this AD, an engine listed by SN 
in Table 2 of this AD, that has HPC cycles since overhaul greater 
than those shown in Table 3 of this AD, or that has an HPC with 
1,500 or more CSO greater than the CSO of the HPT may be returned to 
service without the limitations of paragraph (c) of this AD after an 
HPC overhaul is performed and EITHER of the following have been 
done:
    (1) The HPC and HPT have been modified by the following PW SB's, 
or earlier revisions: PW4ENG 72-484, Revision 3, dated July 1, 1997; 
PW4ENG 72-486, Revision 2, dated April 28, 1998; PW4ENG 72-575, 
Revision 2, dated July 29, 1998; and PW4ENG 72-514, Revision 3, 
dated August 10, 1999; OR
    (2) The engine has been converted to the Phase III configuration 
by the following PW SB's or earlier revisions: PW4ENG 72-490, 
Revision 1, dated August 2, 1994; or PW4ENG 72-504, Revision 1, 
dated May 9, 1995; or PW4ENG 72-572, dated June 16, 1995.
    (i) Any engine listed in the applicability of this AD inducted 
into the shop for HPC overhaul after the effective date of this AD 
must meet the requirements of paragraphs (h)(1) or (h)(2) of this AD 
before return to service.

Definitions

    (j) 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

[[Page 21086]]

the applicable fits and clearances section of the engine manual.
    (2) An HPT overhaul is defined as restoration of the HPT module 
stage 1 and 2 blade tip clearances to the limits specified in the 
applicable fits and clearances section of the engine manual.

Alternative Methods of Compliance

    (k) 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 shall submit their requests through an appropriate FAA 
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

    (l) 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 accomplished.

Effective Date

    (m) This amendment becomes effective May 14, 2001.

    Issued in Burlington, Massachusetts on April 20, 2001.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-10463 Filed 4-26-01; 8:45 am]
BILLING CODE 4910-13-P