AD Amdt-39-11424

[Federal Register Volume 64, Number 223 (Friday, November 19, 1999)]
[Rules and Regulations]
[Pages 63184-63187]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-29826]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-69; Amendment 39-11424; AD 98-21-22 R1]
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 revises an existing airworthiness directive 
(AD), applicable to Pratt & Whitney JT9D series turbofan engines, that 
currently requires initial and repetitive eddy current inspections 
(ECI) of 14th and 15th stage high pressure compressor (HPC) disks for 
cracks, and removal of cracked disks and replacement with

[[Page 63185]]

serviceable parts. This amendment revises the definition of a shop 
visit to make compliance less restrictive, and adds references to a 
Nondestructive Inspection Procedure attached to applicable service 
bulletins. This amendment is prompted by feedback from operators saying 
that the shop visit definition in the current AD made AD compliance 
unnecessarily restrictive. The actions specified by this AD are 
intended to prevent 14th and 15th stage HPC disk rupture, which could 
result in an uncontained engine failure and damage to the airplane.

DATES: Effective January 18, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 18, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from Pratt & Whitney, Publications Department, Supervisor 
Technical Publications Distribution, M/S 132-30, 400 Main St., East 
Hartford, CT 06108; telephone (860) 565-5570. This information may be 
examined at the Federal Aviation Administration (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: 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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by revising airworthiness 
directive (AD) 98-21-22, Amendment 39-10830 (63 FR 55500, October 16, 
1998), which is applicable to Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, 
-7Q3, and JT9D-7R4 series turbofan engines, was published in the 
Federal Register on March 30, 1999 (64 FR 15137). The proposal would 
change the definition of a shop visit from what appears in the current 
AD, ``the induction of an engine into the shop for scheduled 
maintenance'' to ``a low pressure turbine module removal.'' In 
addition, the proposal would add references to the Nondestructive 
Inspection Procedure No. 858 (NDIP-858), dated November 7, 1995, 
attached to the various versions of the referenced alert service 
bulletins (ASBs), which was inadvertently omitted from the current AD.

Comments

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

Difference Between Service Documents and AD

    One commenter notes that the reinspection interval for the 14th 
stage disk in the proposal differs from the reinspection interval 
provided in the applicable service documents. While the proposal 
provides for reinspection at intervals not to exceed 4,000 cycles-in-
service (CIS) since last eddy current inspection (ECI), the ASB calls 
for reinspection whenever the high pressure compressor is disassembled 
sufficiently to access the disk, defined as the removal of the low 
pressure turbine shaft, after accumulating 100 or more cycles since 
last inspection. The commenter states that this difference creates a 
conflict between the proposed AD and the service documents.
    The Federal Aviation Administration (FAA) does not concur. The 
proposal would incorporate ASB JT9D-7R4-A72-524 by reference only for 
the purpose of providing direction on how to perform the inspection and 
the reject criteria. The proposal contains its own reinspection 
interval, which would take precedence over any interval contained in 
the service documents for purposes of complying with the proposed AD. 
There is no conflict. The FAA views the reinspection interval in the 
service documents as more conservative than that required by the 
proposed AD. The proposed AD, however, does not prohibit additional 
inspections performed in accordance with the interval stated in the 
service documents. The FAA has determined that the reinspection 
interval provided in the proposal provides a sufficient level of 
safety.

Commenter Concurs

    One commenter agrees with the proposal as stated.
    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.

No Additional Economic Impact

    Since this revised rule only changes the definition of the shop 
visit and adds reference to the NDIP, there is no effect on the 
economic analysis.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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

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


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-10830 (63 FR 
55500, October 16, 1998), and by adding a new airworthiness directive, 
Amendment 39-11424, to read as follows:

98-21-22 R1  Pratt & Whitney: Amendment 39-11424. Docket 95-ANE-69. 
Revises AD 98-21-22, Amendment 39-10830.

    Applicability: Pratt & Whitney (PW) Model JT9D-59A, -70A, -7Q, -
7Q3, and JT9D-7R4 series turbofan engines, with the following 14th and 
15th stage high pressure compressor (HPC) disks installed: Part Numbers 
(P/Ns) 5000814-01, 790014, 789914, 790114, 5000815-01, 5000815-021, 
704315, 704315-001, 786215, 786215-001, 704314, 789814, and 790214. 
These

[[Page 63186]]

engines are installed on but not limited to Airbus A300 and A310 series 
aircraft, Boeing 747 and 767 series aircraft, and McDonnell Douglas DC-
10 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 (f) 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 14th and 15th stage HPC disk rupture, which could 
result in an uncontained engine failure and damage to the airplane, 
accomplish the following:

Inspections

    (a) Inspect 14th stage HPC disks, P/N 5000814-01, in accordance 
with Nondestructive Inspection Procedure No. 858 (NDIP-858), dated 
November 7, 1995, attached to PW Alert Service Bulletin (ASB) No. 
JT9D-7R4-524, dated December 13, 1995, or Revision 1, dated June 26, 
1997, as follows:
    (1) Perform an initial eddy current inspection (ECI) for cracks 
as follows:
    (i) For disks with 7,000 or more cycles since new (CSN), and 
3,000 or more cycles in service (CIS) since last shop visit, on the 
effective date of this AD, inspect within the next 1,000 CIS after 
the effective date of this AD, or at the next shop visit, whichever 
occurs first.
    (ii) For disks with 7,000 or more CSN, and less than 3,000 CIS 
since last shop visit, on the effective date of this AD, inspect 
within 4,000 CIS since the last shop visit, or at the next shop 
visit, whichever occurs first.
    (iii) For disks with less than 7,000 CSN on the effective date 
of this AD, inspect at the next shop visit after the effective date 
of this AD, but before exceeding 4,000 CIS since last shop visit, or 
8,000 CSN, whichever occurs later.
    (iv) For uninstalled disks on or after the effective date of 
this AD, inspect prior to installation.
    (2) Thereafter, perform ECI for cracks at intervals not to 
exceed 4,000 CIS since last ECI.
    (3) Prior to further flight, remove cracked disks and replace 
with serviceable parts.
    (b) Inspect 14th stage HPC disks, P/Ns 790014, 789914, 790114, 
and 15th stage HPC disks, P/N's 5000815-01, 5000815-021, 704315, 
704315-001, 786215, and 786215-001, in accordance with NDIP-858, 
dated November 7, 1995, attached to PW ASB No. JT9D-7R4-A72-524, 
dated December 13, 1995, or Revision 1, dated June 26, 1997, or PW 
ASB No. A6232, dated December 13, 1995, or Revision 1, dated January 
11, 1996, or Revision 2, dated June 26, 1997, as applicable, as 
follows:
    (1) Perform an initial ECI for cracks as follows:
    (i) For disks with 6,500 or more CSN, and 3,000 or more CIS 
since last shop visit, on the effective date of this AD, inspect 
within the next 1,000 CIS after the effective date of this AD, or at 
the next shop visit, whichever occurs first.
    (ii) For disks with 6,500 or more CSN, and less than 3,000 CIS 
since last shop visit, on the effective date of this AD, inspect 
within 4,000 CIS since the last shop visit, or at the next shop 
visit, whichever occurs first.
    (iii) For disks with less than 6,500 CSN on the effective date 
of this AD, inspect at the next shop visit after the effective date 
of this AD, but before exceeding 4,000 CIS since last shop visit, or 
7,500 CSN, whichever occurs later.
    (iv) For uninstalled disks on or after the effective date of 
this AD, inspect prior to installation.
    (2) Thereafter, perform ECI for cracks at intervals not to 
exceed 4,000 CIS since last ECI.
    (3) Prior to further flight, remove cracked disks and replace 
with serviceable parts.
    (c) Inspect 14th stage HPC disks, P/Ns 704314, 789814, and 
790214, in accordance with NDIP-858, dated November 7, 1995, 
attached to PW ASB No. A6232, original issue, dated December 13, 
1995, or Revision 1, dated January 11, 1996, or Revision 2, dated 
June 26, 1997, as follows:
    (1) Perform an initial ECI for cracks as follows:
    (i) For disks with 2,000 or more CSN, and 2,000 or more CIS 
since last shop visit, on the effective date of this AD, inspect 
within the next 1,000 CIS after the effective date of this AD, or at 
the next shop visit, whichever occurs first.
    (ii) For disks with 2,000 or more CSN, and less than 2,000 CIS 
since last shop visit, on the effective date of this AD, inspect 
within 3,000 CIS since the last shop visit, or at the next shop 
visit, whichever occurs first.
    (iii) For disks with 2,000 or more CSN, and no previous shop 
visits, inspect within 3,000 CIS after the effective date of this 
AD, or at the next shop visit, whichever occurs first.
    (iv) For disks with less than 2,000 CSN on the effective date of 
this AD, inspect at the next shop visit after the effective date of 
this AD, but before exceeding 5,000 CSN.
    (iv) For uninstalled disks on or after the effective date of 
this AD, inspect prior to installation.
    (2) Thereafter, perform ECI for cracks at intervals not to 
exceed 3,000 CIS since last ECI.
    (3) Prior to further flight, remove cracked disks and replace 
with serviceable parts.

Inspection Report

    (d) Within 30 days of inspection, report inspection results on 
the form labeled ``14th and 15th Stage HPC Disk Inspection Report,'' 
to Pratt & Whitney Customer Technical Support. The fax number is 
listed on that form which is attached to PW ASB No. JT9D-7R4-A72-
524, Revision 1, dated June 26, 1997, or PW ASB No. A6232, Revision 
2, June 26, 1997. Reporting requirements have been approved by the 
Office of Management and Budget and assigned OMB control number 
2120-0056.

Definition

    (e) For the purpose of this AD, a shop visit is defined as a low 
pressure turbine module removal.

Alternative Method of Compliance

    (f) 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. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Engine Certification Office.

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

Ferry Flight

    (g) 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 requirements of this AD can be accomplished.

Incorporation by Reference

    (h) The actions required by this AD shall be done in accordance 
with the following Pratt & Whitney service documents:

[[Page 63187]]



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          Document No.                     Pages                   Revision                     Date
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ASB No. A6232...................  1......................  2......................  June 26, 1997.
                                  2......................  Original...............  December 13, 1995.
                                  3,4....................  1......................  January 11, 1996.
                                  5,6....................  2......................  June 26, 1997.
                                  7-10...................  Original...............  December 13, 1995.
    Total Pages: 10.
ASB No. JT9D-7R4-A72-524........  1......................  1......................  June 26, 1997.
                                  2-5....................  Original...............  December 13, 1995.
                                  6,7....................  1......................  June 26, 1997.
                                  8-11...................  Original...............  December 13, 1995.
    Total Pages: 11
NDIP-858........................  1-33...................  Original...............  November 7, 1995.
    Total Pages: 33
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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, Publications Department, 
Supervisor Technical Publications Distribution, M/S 132-30, 400 Main 
St., East Hartford, CT 06108; telephone (860) 565-5570. 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

    (i) This amendment becomes effective on January 18, 2000.

    Issued in Burlington, Massachusetts, on November 9, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-29826 Filed 11-18-99; 8:45 am]
BILLING CODE 4910-13-U