https://www.aviationpros.com/aircraft-maintenance-technology/aircraft-technology/rotorcraft/press-release/12399825/pratt-whitney-canada-pratt-whitney-canada-to-provide-pt6c-67d-engine-for-temscos-uh-1h-helicopter-engine-conversion-program
Pratt & Whitney Canada to Provide PT6C-67D Engine for TEMSCO's UH-1H Helicopter Engine Conversion...
The supplemental type certificate (STC) for the engine conversion program is held by TEMSCO Helicopters, Inc., of Alaska.