[Federal Register Volume 67, Number 10 (Tuesday, January 15, 2002)]
[Proposed Rules]
[Pages 1913-1915]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-905]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NE-49-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & 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 & Whitney PW4000 series turbofan engines. That AD currently 
requires operators to perform initial and repetitive inspections for 
cracking of high pressure compressor (HPC) front drum rotors based on 
cycle usage. That AD also requires the removal from service of any 
cracked HPC front drum rotors. This proposal clarifies inspection 
requirements for cracking of high pressure compressor (HPC) front drum 
rotors that have fewer than 1,000 cycles-since-new (CSN). This proposal 
is prompted by comments from operators seeking more clarity about the 
inspection requirements of paragraph (a)(1) of the current AD. The 
actions specified in the proposed AD are intended to prevent HPC drum 
rotor failure from cracks that could result in an uncontained engine 
failure and damage to the airplane.

DATES: Comments must be received by February 14, 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-49-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 Street, East Hartford, CT 
06108. 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: Tara Goodman, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington MA 01803-5299; telephone: 781-
238-7130, 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-49-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-49-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On October 12, 2001, the FAA issued AD 2001-20-13, Amendment 39-
12461

[[Page 1914]]

(66 FR 52023, October 12, 2001), to require operators to perform 
initial and repetitive inspections for cracking of HPC front drum 
rotors based on cycle usage. That amendment also requires the removal 
from service of any cracked HPC front drum rotors. That action was 
prompted by reports that 11 HPC front drum rotors have been found 
cracked on the spacer surface between the sixth and seventh stage 
disks. That condition, if not corrected, could result in HPC front drum 
rotor failure that could result in an uncontained engine failure and 
damage to the airplane.
    Since that AD was issued, the FAA received three comments from 
operators stating that the inspection requirements stated in paragraph 
(a)(1) are inconsistent with the alert service bulletin. The FAA agreed 
with these comments and paragraph (a)(1) has been changed to clarify 
inspection requirements for cracking of HPC front drum rotors that have 
fewer than 1,000 CSN.

Manufacturer's Service Information

    The FAA has reviewed and approved the technical contents of Pratt & 
Whitney Alert Service Bulletin (ASB) PW4ENG A72-722, dated September 
29, 2000 and (ASB) PW4ENG A72-722, Revision 1, dated June 7, 2001 that 
describe procedures for initial and repetitive inspections for cracking 
of HPC front drum rotors based on cycle usage and the removal from 
service of any cracked HPC front drum rotors.

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, products of this same type design, the proposed AD would 
supersede AD 2001-20-13 to clarify inspection requirements for front 
drum rotors that have fewer than 1,000 cycles-since-new. The actions 
are required to be done in accordance with the service bulletins 
described previously.

Economic Analysis

    The FAA estimates that there will be no additional costs 
attributable to this proposed supersedure.

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.

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 39-12461, (66 FR 
52023, October 12, 2001), and by adding a new airworthiness directive:

Pratt & Whitney: Docket No. 2000-NE-49-AD. Supersedes AD 2001-20-13, 
Amendment 39-12461.

Applicability

    This airworthiness directive (AD) applies to Pratt & Whitney 
(PW) models PW4052, PW4056, PW4060, PW4062, PW4152, PW4156A, PW4158, 
PW4460, and PW4462 turbofan engines. These engines are installed on 
but not limited to Boeing 747, 767, McDonnell Douglas MD-11, Airbus 
Industrie A300, and A310 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 (d) 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

    Required as indicated, unless accomplished previously.
    To prevent failure of the high pressure compressor (HPC) front 
drum rotor from cracks, that could result in an uncontained engine 
failure and damage to the airplane, do the following:

Initial Inspection

    (a) Perform an initial borescope inspection for cracks in 
accordance with the Accomplishment Instructions, On-Wing paragraphs 
1 through 13, of Pratt & Whitney (PW) Alert Service Bulletin (ASB) 
No. PW4ENG A72-722, dated September 29, 2000 or Revision 1, dated 
June 7, 2001, as follows:
    (1) For HPC front drum rotors with fewer than 1,000 cycles-
since-new (CSN) on the effective date of this AD, perform an initial 
inspection within 500 cycles-in-service (CIS) after accumulating 
1,000 CSN.
    (2) For HPC front drum rotors with 1,000 CSN or more after the 
effective date of this AD, perform an initial inspection within 500 
CIS after the effective date of this AD.
    (3) If the presence of a crack needs to be confirmed, perform an 
eddy current inspection (ECI) within five flight cycles of the on-
wing borescope inspection.
    (4) If the presence of a crack needs to be confirmed and the 
suspect crack indication extends from the knife edges to the disk 
radius directly adjacent to the spacer wall of the sixth or seventh 
stage as shown in Figures 2 and 3 of PW ASB No. PW4ENG A72-722, 
dated September 29, 2000, or Revision 1, dated June 7, 2001, the ECI 
inspection must be done before further flight.
    (5) If the presence of a crack is confirmed, remove and replace 
the HPC front drum rotor with a serviceable part before further 
flight.
    (6) HPC front drum rotors fluorescent penetrant inspected at the 
last shop visit, as cited in the compliance section of the ASB, 
within 500 cycles of the effective date of this AD, satisfy the 
initial inspection requirement.

Repetitive Inspections

    (b) Thereafter, perform borescope inspections within 2,200 
cycles-since-last-inspection, in accordance with the Accomplishment 
Instructions, On-Wing paragraphs 1 through 13, of PW ASB No. PW4ENG 
A72-722, dated September 29, 2000, or Revision 1, dated June 7, 
2001.
    (1) If the presence of a crack needs to be confirmed, perform an 
ECI within five flight cycles.
    (2) If the presence of a crack needs to be confirmed and the 
suspect crack indication extends from the knife edges to the disk 
radius directly adjacent to the spacer wall of the sixth or seventh 
stage as shown in Figures 2 and 3 of PW ASB No. PW4ENG A72-722, 
dated September 29, 2000, or Revision 1, dated June 7, 2001, the ECI 
inspection must be done before further flight.

[[Page 1915]]

    (3) If the presence of a crack is confirmed, remove and replace 
with a serviceable HPC front drum rotor before further flight.

Definition of Suspect Crack Indication

    (c) For the purposes of this AD, a suspect crack indication is 
defined as a response from the visual borescope inspection procedure 
that denotes the possible presence of a material discontinuity and 
requires interpretation to determine its significance.

Alternative Methods of Compliance

    (d) 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 request through an appropriate Federal 
Aviation Administration (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

    (e) 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.

    Issued in Burlington, Massachusetts, on January 7, 2002.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 02-905 Filed 1-14-02; 8:45 am]
BILLING CODE 4910-13-P