Airworthiness directives: Pratt & Whitney,

[Federal Register: November 18, 1999 (Volume 64, Number 222)]

[Rules and Regulations]

[Page 62975-62976]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr18no99-3]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-06-AD; Amendment 39-11334; AD 99-20-04]

RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney JT9D-7R4 Series Turbofan Engines; Correction

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; correction

SUMMARY: This document makes a correction to Airworthiness Directive (AD) 99-20-04 applicable to certain Pratt & Whitney (PW) JT9D series turbofan engines that was published in the Federal Register on September 24, 1999 (64 FR 51683). The final rule inadvertently references HPC disk fracture instead of HPT disk fracture and one service bulletin (SB) reference in the compliance section is incorrect. This document corrects those references. The Compliance section in the final rule was inadvertently changed to incorporate the compliance requirements used in a similar PW2000 Airworthiness Directive. The Compliance requirements were correctly published in the NPRM, but were published incorrectly in the Final Rule. This correction will reinstate the compliance requirements originally published in the NPRM, and as intended for the JT9D. In all other respects, the original document remains the same.

[[Page 62976]]

EFFECTIVE DATE: November 18, 1999.

FOR FURTHER INFORMATION CONTACT: Peter White, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7128, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A final rule airworthiness directive applicable to Pratt & Whitney (PW) JT9D-7R4 series turbofan engines, was published in the Federal Register on September 24, 1999 (64 FR 51683). The Rule should reference HPT disk fracture instead of HPC disk fracture. In addition, a typographical error occurred and, as a result, one Service Bulletin reference regarding the performance of the inspections is incorrect and has been corrected to refer to the SB that contains the actual inspection procedure. The following corrections are needed:

Sec. 39.13 [Corrected]

1. On page 51684, in the first column, in the Compliance Section, in the first paragraph, in the second line, ``To prevent a high pressure compressor (HPC) disk fracture'' is corrected to read ``To prevent a high pressure turbine (HPT) disk fracture.''

2. On page 51684, in the second column, in the Compliance Section, in paragraph (a), in the sixth, seventh, eighth and ninth lines, ``''PW SB JT9D-7R4-72-552, Revision 1, dated February 17, 1999 at each separation of the HPT disk from the HPT module after the effective date of the AD.'' is corrected to read ``PW SB JT9D-7R4-72-553, Revision 1, dated February 17, 1999 at each HPT disk piece part accessibility after the effective date of this AD.'' David A. Downey, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

[FR Doc. 99-29824Filed11-17-99; 8:45 am]

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