AD 2001-04-11

[Federal Register Volume 66, Number 44 (Tuesday, March 6, 2001)]
[Rules and Regulations]
[Pages 13416-13418]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-4890]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-56-AD; Amendment 39-12130; AD 2001-04-11]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Pratt & Whitney (PW) JT9D series turbofan 
engines. This amendment requires initial and repetitive detailed eddy 
current inspections for cracks in 1st stage high pressure turbine (HPT) 
disks, and, if necessary, replacement with serviceable parts. This 
amendment is prompted by the discovery of a crack in the web of one 
cooling air hole on a 1st stage HPT disk. The actions specified by this 
AD are intended to prevent 1st stage HPT disk cracking, which could 
result in an uncontained engine failure and damage to the aircraft.

DATES: Effective May 7, 2001. The incorporation by reference of certain 
publications listed in the regulations is approved by the Director of 
the Federal Register as of May 7, 2001.

ADDRESSES: The service information referenced in this AD may be 
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone 860-565-8770, fax 860-565-4503. This information may be 
examined at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA, or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Wego Wang, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone: 781-238-
7134, fax: 781-238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an AD that is 
applicable to certain PW JT9D series turbofan engines was published in 
the Federal Register on March 7, 2000 (65 FR 11940). That action 
proposed to require initial and repetitive detailed eddy current 
inspections for cracks in 1st stage HPT disks, and, if necessary, 
replacement with serviceable parts.

Comments Received

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Rule as Proposed

    Two commenters state their support of the notice of proposed 
rulemaking (NPRM) as written.

Economic Analysis Question

    One commenter states that the cost incurred due to premature engine 
removal is not captured in the NPRM economic analysis. This cost would 
adversely impact operators when an engine must be removed prematurely 
in order to perform disk inspections. The cost would specifically 
impact this operator when an engine that is not under its maintenance 
program is acquired and is inducted into its system.
    The FAA does not agree. The NPRM cost analysis is based on the 
costs of parts and labor to U.S. operators needed to perform the 
required initial inspections, and is not specific to any particular 
maintenance system. However, the economic analysis is corrected to 
clarify that the cost totals are for initial inspection only.

Two Types of Compliance Times

    Two commenters state that the NPRM's proposed compliance times are

[[Page 13417]]

inconsistent with the compliance times referenced in PW Alert Service 
Bulletins (ASB's) JT9D A6376, dated July 28, 1999 and JT9D-7R4-A72-563, 
dated July 28, 1999. Specifically, for disks that have had a prior 
fluorescent penetrant inspection, the NPRM proposed reinspections based 
on cycles-since-new (CSN) intervals. The ASB's, however, require 
reinspections based on cycles-in-service (CIS) intervals.
    The FAA agrees. The compliance is corrected as follows:
    <bullet> In the JT9D series engines section, in paragraph 
(a)(4)(ii) and (a)(4)(iii), the compliance time type is changed from 
CSN to CIS.
    <bullet> In the JT9D-7R4 series engines section, in paragraph 
(b)(4)(ii) and (b)(4)(iii), the compliance time type is changed from 
CSN to CIS.

Incorrect Aircraft Model Applicability

    One commenter states that under the Applicability section in the 
NPRM, the reference to Airbus Industrie A300 series aircraft is 
incorrect, and should read Airbus Industrie A310 series aircraft.
    The FAA agrees. The Applicability section is corrected in this 
amendment.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Economic Analysis

    There are approximately 330 engines of the affected design in the 
worldwide fleet. The FAA estimates that 220 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, that 
it would take approximately 4.5 work hours per engine to accomplish the 
initial inspection, and that the average labor rate is $60 per work 
hour. Required parts would cost approximately $165,000 per engine. 
Based on these figures, the total initial inspection cost impact of the 
proposed AD on U.S. operators is estimated to be $36,359,400.

Regulatory Impact

    This 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 rule.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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, Incorporation by 
reference, 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:

    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:

2001-04-11, Pratt & Whitney: Amendment 39-12130. Docket No. 99-NE-
56-AD.

    Applicability: Pratt & Whitney (PW) JT9D-7R4D, -7R4D1, -7R4E, -
7R4E1 (AI-500), -7, -7A, -7AH, -7H, -7F, and -20 series turbofan 
engines, installed on but not limited to Boeing 747 and 767 series, 
McDonnell Douglas DC-10 series, and Airbus Industrie A310 series 
aircraft.

    Note 1: This airworthiness directive (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 (c) 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 1st stage high pressure turbine (HPT) disk cracking, 
which could result in an uncontained engine failure and damage to 
the aircraft, accomplish the following:

JT9D Series

    (a) For PW JT9D-7, -7A, -7AH, -7H, -7F, and -20 series turbofan 
engines, with 1st stage HPT disks, part numbers (P/Ns) 761401, 
811401, 823401, 825601, 826001, and 826301:

Initial Inspection

    (1) Perform the initial detailed eddy current inspection (ECI) 
for cracks in accordance with the Accomplishment Instructions of PW 
Alert Service Bulletin (ASB) No. JT9D A6367, dated July 28, 1999.
    (2) Inspect at the following compliance times, depending on 
whether parts have had prior fluorescent penetrant inspections (FPI) 
or not.

Initial Compliance Times

No Prior FPI

    (3) The following are the initial compliance times for parts 
that have had no prior FPI:
    (i) For disks with more than 8,000 total part cycles-since-new 
(CSN) on the effective date of this AD, inspect within 250 cycles-
in-service (CIS) after the effective date of this AD.
    (ii) For disks with at least 6,000 CSN though no more than 8,000 
total part CSN on the effective date of this AD, inspect within 
1,000 CIS after the effective date of this AD.
    (iii) For disks with at least 4,000 CSN though no more than 
5,999 total part CSN on the effective date of this AD, inspect 
within 2,000 CIS after the effective date of this AD.
    (iv) For disks with less than 4,000 total part CSN on the 
effective date of this AD, inspect prior to accumulating 6,000 total 
part CSN.

Prior FPI Accomplished

    (4) The following are the initial compliance times for parts 
that have had a previous FPI:
    (i) For disks with more than 8,000 CIS since last FPI on the 
effective date of this AD, inspect within 250 CIS after the 
effective date of this AD.
    (ii) For disks with at least 6,000 CIS though no more than 8,000 
CIS since last FPI on the effective date of this AD, inspect within 
1,000 CIS after the effective date of this AD.
    (iii) For disks with at least 4,000 CIS though no more than 
5,999 CIS since last FPI on the effective date of this AD, inspect 
within 2,000 CIS after the effective date of this AD.
    (iv) For disks with less than 4,000 CIS since last FPI on the 
effective date of this AD, inspect prior to accumulating 6,000 CIS 
since last FPI on the effective date of this AD.

Repetitive Inspections

    (5) Thereafter, perform detailed ECI for cracks:
    (i) At intervals not to exceed 6,000 CIS since last ECI.
    (ii) Inspect in accordance with the Accomplishment Instructions 
of PW ASB No. JT9D A6367, dated July 28, 1999.

[[Page 13418]]

Cracked Disks

    (6) Prior to further flight, replace cracked disks with 
serviceable parts.

JT9D-7R4 Series

    (b) For PW JT9D-7R4D, -7R4D1, -7R4E, and -7R4E1 (AI-500) series 
turbofan engines, with 1st stage HPT disks, P/N 825601:

Initial Inspection

    (1) Perform the initial detailed ECI for cracks in accordance 
with the Accomplishment Instructions of PW ASB No. JT9D-7R4-A72-563, 
dated July 28, 1999.
    (2) Inspect at the following compliance times, depending on 
whether parts have had prior FPI or not.

Initial Compliance Times

No Prior FPI

    (3) The following are the initial compliance times for parts 
that have had no prior FPI:
    (i) For disks with more than 10,000 total part CSN on the 
effective date of this AD, inspect within 250 CIS after the 
effective date of this AD.
    (ii) For disks with at least 8,000 CSN though no more than 
10,000 total part CSN on the effective date of this AD, inspect 
within 1,000 CIS after the effective date of this AD.
    (iii) For disks with at least 6,000 CSN though no more than 
7,999 total part CSN on the effective date of this AD, inspect 
within 2,000 CIS after the effective date of this AD.
    (iv) For disks with less than 6,000 total part CSN on the 
effective date of this AD, inspect prior to accumulating 8,000 total 
part CSN.

Prior FPI Accomplished

    (4) The following are the initial compliance times for parts 
that have had a previous FPI:
    (i) For disks with more than 10,000 CIS since last FPI on the 
effective date of this AD, inspect within 250 CIS after the 
effective date of this AD.
    (ii) For disks with at least 8,000 CIS though no more than 
10,000 CIS since last FPI on the effective date of this AD, inspect 
within 1,000 CIS after the effective date of this AD.
    (iii) For disks with at least 6,000 CIS though no more than 
7,999 CIS since last FPI on the effective date of this AD, inspect 
within 2,000 CIS after the effective date of this AD.
    (iv) For disks with less than 6,000 CIS since last FPI on the 
effective date of this AD, inspect prior to accumulating 8,000 CIS 
since last FPI on the effective date of this AD.

Repetitive Inspections

    (5) Thereafter, perform detailed ECI for cracks:
    (i) At intervals not to exceed 8,000 CIS since last ECI.
    (ii) Inspect in accordance with the Accomplishment Instructions 
of PW ASB No. JT9D-7R4-A72-563, dated July 28, 1999.

Cracked Disks

    (6) Prior to further flight, replace cracked disks with 
serviceable parts.

Alternative Methods of Compliance

    (c) 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 request 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.

Ferry Flights

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the aircraft to a location where 
the inspection requirements of this AD can be accomplished.

Incorporation by Reference

    (e) The actions required by this AD must be done in accordance 
with the following Pratt & Whitney Alert Service Bulletins:

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           Document No.                Pages              Revision                          Date
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JT9D A6367.......................         1-12   Original.................  July 28, 1999.
      Total pages: 12.
JT9D-7R4-A72-563.................         1-37   Original.................  July 28, 1999.
      Total pages: 37.
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    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Pratt & Whitney, 400 Main 
Street, East Hartford, CT 06108; telephone: 860 565-6600, fax: 860 
565-4503. Copies may be inspected at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA; or at the Office of the Federal Register, 800 North 
Capitol Street, NW, suite 700, Washington, DC.

Effective Date

    (f) This amendment becomes effective on May 7, 2001.


    Issued in Burlington, Massachusetts, on February 21, 2001.
David A. Downey,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-4890 Filed 3-5-01; 8:45 am]
BILLING CODE 4910-13-P