[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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