Installation of steel transmission fitting fabricated in accordance with Croman Drawing S-6120-62113-CRO41, Revision D, dated January 8, 1982, or later Federal Aviation Administration (FAA) approved revision; installed in accordance with Croman Installation Instructions S-6120-62113-CRO41-Inst, Revision IR, dated August 10, 2011, or later FAA- approved revision.

Manufacture side-facing seat mounting structure

Upgrade of the S6135-20600 series main gearbox by replacing input free-wheeling units in accordance with Carson drawing. IFWU INSTL Carson S-61 No. CHI-R-001, no revision, dated 12-15-04 and Carson Installation Instructions Report CHI-R-INSTALL, no revision, dated 12-14-04.

Fabrication of reinforcement kit - aft fuselage station 493. For model S61A, applies to S/N 61094. For model S61NM, applies to S/N 66454

In accordance with Carson Services, Inc. Report CSI-01-1001 Revision A dated August 23, 2001, increase Category B takeoff and landing altitude limit to 12,000 ft Hd. In addition, increase enroute and external load altitude limit to 14,000 ft Hd.

Modification of main rotor blade part number 61170-20201 in accordance with Master Drawing List RR 9633-08, Revision A, dated September 17, 2002, or later FAA approved revision. Retirement life for the modified main rotor blade, part number RR-61170-20201 is 21,200 total time in service.