A little background story.
Bell had proposed the UH-1B for the competition but the USAF asked Bell to develop a special version of the "Bravo" in using the General Electric T58 turboshaft as a powerplant. The USAF already had a large inventory of these engines for its fleet of Sikorsky HH-3 Jolly Green Giant rescue helicopters and wanted to have commonality between the types. This engine was capable of 1,250 hp (932 kW) compared to the UH-1B's 1,100 hp (820 kW) T53-L11.
In response Bell proposed an upgraded version of the UH-1B with the T58 engine installed. The resulting UH-1F had the shorter cabin of the "Bravo" Huey, but with the longer tail boom, rotor and transmission of the UH-1D.
Due to the Huey's configuration, Bell installed the T58 engine backwards compared to the HH-3. The Huey's engine is behind the transmission, whereas the HH-3's engines are in front of the transmission. Externally, the only visible differences from UH-1B were the engine exhaust, which exited to the right side of the engine and the longer tail boom.
The UH-1F was introduced into the USAF inventory on 20 February 1964. The USAF took delivery of 119 with production ending in 1967. Many of the aircraft served in southeast Asia with the 20th Special Operations Squadron and some were converted to the armed UH-1P configuration.
Definitely gonna watch this project closely.
