Airworthiness directives: Pratt & Whitney,
[Federal Register: October 16, 1998 (Volume 63, Number 200)]
[Rules and Regulations]
[Page 55500-55503]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16oc98-3]
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.
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.
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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
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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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
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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:
Document No.
Pages
Revision
Date
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
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
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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. 98-27194Filed10-15-98; 8:45 am]
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