2008-22-16: Repetitive heavy lift (RHL)

2008-22-16 General Electric Company (GE): Amendment 39-15712. Docket No. FAA-2008-0808; Directorate Identifier 2008-NE-18-AD. Effective Date (a) This airworthiness directive (AD) becomes effective December 1, 2008. Affected ADs (b) None. Applicability (c) This AD applies to GE CT58 series turboshaft engines with a compressor spool, part number (P/N) 5920T82G07, 6010T57G07, or 6010T57G08, installed. These engines are installed on, but not limited to, Sikorsky S-61A, S-61L, S-61N, S-61R, S-62, and Columbia 107-II helicopters. Unsafe Condition (d) This AD results from reports of cracks originating from the inner faces of the locking screw holes in the compressor spool. We are issuing this AD to prevent cracks due to repetitive heavy lift (RHL) missions. Cracks could result in an uncontained rotor burst and damage to, or loss of, the helicopter and serious injuries to any person onboard. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. Recalculating Compressor Spool Cycles (f) Within 30 days after the effective date of this AD, recalculate the life of compressor spools, P/N 5920T82G07, 6010T57G07, or 6010T57G08, using an RHL mission multiplying factor of both 3.7 cycles per hour and 6.0 cycles per hour. GE Alert Service Bulletin CT58 S/B 72-A0162, Revision 12, dated April 17, 2008, contains information on calculating life cycles for the compressor spools. Removing Compressor Spools Based on the New Recalculated Cycles (g) Before January 1, 2010, remove the compressor spools, P/N 5920T82G07, 6010T57G07, or 6010T57G08, at the earlier of when: (1) The compressor spool reaches its part life limit as calculated using an RHL multiplying factor of 3.7, or (2) You can see the spool at shop visit after it has reached its part life limit using an RHL multiplying factor of 6.0. (h) On January 1, 2010 and thereafter, remove the engine before the compressor spool exceeds its part life limit as calculated using an RHL multiplying factor of 6.0. (i) As of January 1, 2010, don't use an RHL multiplying factor of 3.7 to calculate the life of the compressor spool. Installation Prohibition (j) After the effective date of this AD, don't install any engine that has a compressor spool installed that meets or exceeds the life limits as calculated in paragraph (g)(1) through (g)(2) or (h) of this AD. Alternative Methods of Compliance (k) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Related Information (l) GE Alert Service Bulletin CT58 S/B 72-A0162, Revision 12, dated April 17, 2008, pertains to the subject of this AD. (m) Contact Christopher J. Richards, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: christopher.j.richards@faa.gov; telephone (781) 238-7133; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (n) None.