Aircraft STC directory
Sikorsky Aircraft S-61NM STCs
The Jun 30, 2026 FAA DRS snapshot contains 22 selected supplemental type certificates with status Current whose public applicability data names the Sikorsky Aircraft S-61NM. Use it to identify modification scope and recorded holders—not to determine serial-number effectivity, compatibility, installation approval, or commercial availability.
Modification demand surface
Recently revised S-61NM STCs
Showing the 22 most recently revised records. Each entry links to the FAA source and separates public approval data from private commercial claims.
Fabrication of Helipro replacement windshields.
FAA holder: Croman Corporation
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.
FAA holder: Park Technologies, LLC
Installation of NASI NREM18M Air Conditioning Module.
FAA holder: National Aircraft Service Inc. (NASI)
Increase of Out of Ground Effect (OGE) Hover Performance.
FAA holder: Carson Helicopters Inc
Increased Category A Performance for the Sikorsky S-61L, S-61N and S-61NM Helicopters.
FAA holder: Carson Helicopters, Inc
Fabrication of replacement transmission fittings.
FAA holder: Croman Corporation
Installation of NASI Air Conditioning Module.
FAA holder: National Aircraft Service Inc
Installation of Carson Helicopters, Inc. composite main rotor blades, P/N 163-101-1.
FAA holder: Carson Helicopters Inc
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.
FAA holder: Carson Helicopters, Inc
Manufacture of a titanium transmission support fitting assembly.
FAA holder: Clayton International Inc.