[Federal Register Volume 63, Number 200 (Friday, October 16, 1998)]
[Rules and Regulations]
[Pages 55500-55503]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-27194]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-69; Amendment 39-10830; AD 98-21-22]
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), 
applicable to Pratt & Whitney JT9D series turbofan engines, that 
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 serviceable parts. This 
amendment is prompted by reports of disk bore cracks found during shop 
inspections on both the 14th and 15th stage HPC disks. 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 aircraft.

DATES: Effective December 15, 1998.


[[Page 55501]]


    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 15, 1998.

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) 565-7700. 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) to include an airworthiness 
directive (AD) that is applicable to Pratt & Whitney (PW) Model JT9D-
59A, -70A, -7Q, -7Q3, and JT9D-7R4 series turbofan engines was 
published in the Federal Register May 6, 1996 (61 FR 20192). That 
action proposed to require initial and repetitive eddy current 
inspections (ECI) of 14th and 15th high pressure compressor (HPC) disks 
for cracks. That action also proposed to require the removal of cracked 
disks and replacement with serviceable parts.
    Since publication of that proposed rule, the Federal Aviation 
Administration (FAA) received several comments that required changing 
the compliance section. The FAA then issued a Supplemental Notice of 
Proposed Rulemaking (SNPRM) on December 23, 1997 (January 5, 1998, 63 
FR 167) that revised the proposed rule by extending the repetitive 
inspection interval and changing the definition of a shop visit. Since 
publication of the SNPRM, interested persons have been afforded an 
opportunity to participate in the making of this amendment. Due 
consideration has been given to the comments received.
    One commenter states that the second sentence of paragraph (d) of 
the compliance section should be revised to note that the fax number 
for reporting also is listed in PW ASB No. A6232, Revision 1, dated 
January 11, 1996. The FAA concurs and has revised this final rule 
accordingly.
    One commenter states that they (a foreign air carrier) will comply 
with this rule.
    One commenter does not operate any of the affected PW JT9D series 
engine models.
    One commenter notes that the changes in the SNPRM will not affect 
actions already taken.
    One commenter has no objections or comments to the rule.
    One commenter requests advance notice of the effective date of this 
AD.
    The FAA concurs and will make the effective date of this final rule 
60 days after the date of publication in the Federal Register, giving 
ample advance warning.
    Since publication of the NPRM, the manufacturer has issued 
revisions to the referenced service bulletins. The new service 
bulletins, PW ASB No. A6232, Revision 2, dated June 26, 1997, and PW 
ASB No. JT9D-7R4-A72-524, Revision 1, dated June 26, 1997, retain Non-
Destructive Inspection Procedure No. 858 (NDIP-858) inspection 
instructions and include terminating actions. In addition, attached to 
NDIP-858, dated November 7, 1995, is the reporting form ``14th and 15th 
Stage HPC Disk Inspection Report,'' referenced in paragraph (d) of this 
AD.
    Also, the FAA has revised the definition of a shop visit in this 
final rule for clarification.
    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 this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 1,100 engines of the affected design in the 
worldwide fleet. The FAA estimates that 170 engines installed on 
aircraft of U.S. registry will be affected by this AD. The FAA 
anticipates that the majority of the required initial and repetitive 
eddy current inspections will take place during regularly scheduled 
maintenance visits, but it will take 3 work hours per engine per 
inspection, and the average labor rate is $60 per work hour. Based on 
these figures, the total cost impact of the AD per engine is estimated 
to be $30,600. Based on these estimates, the total cost of the AD is 
$5,202,000.
    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

    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:

98-21-22 Pratt & Whitney: Amendment 39-10830. Docket 95-ANE-69.

    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/N's) 5000814-01, 790014, 789914, 790114, 5000815-01, 
5000815-021, 704315, 704315-001, 786215, 786215-001, 704314, 789814, 
and 790214. These 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

[[Page 55502]]

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 aircraft, 
accomplish the following:
    (a) Inspect 14th stage HPC disks, P/N 5000814-01, in accordance 
with PW Alert Service Bulletin (ASB) No. JT9D-7R4-524, 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/N's 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 PW ASB No. 
JT9D-7R4-A72-524, Revision 1, dated June 26, 1997, or PW ASB No. 
A6232, Revision 2, 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/N's 704314, 789814, and 
790214, in accordance with PW ASB No. A6232, 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.
    (v) 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.
    (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.
    (e) For the purpose of this AD, a shop visit is defined as the 
induction of an engine into the shop for scheduled maintenance.
    (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.

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

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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) 565-7700. Copies may be 
inspected at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England

[[Page 55503]]

Executive Park, Burlington, MA; or at the Office of the Federal 
Register, 800 North Capitol Street NW., suite 700, Washington, DC.
    (i) This amendment becomes effective on December 15, 1998.

    Issued in Burlington, Massachusetts, on October 5, 1998.
Mark C. Fulmer,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 98-27194 Filed 10-15-98; 8:45 am]
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