The Westland Wessex was a British development of the Sikorsky S-58, with a turboshaft engine replacing the original piston-engine radial.

A military variants of the Cessna 337, the O-2 series was built in some numbers, 501 O-2As going to the USAF for Forward Air Control duties, and some 31 O-2Bs were used in the psychological warfare role in Vietnam.

The Growler was designed as an aircraft-carrier based electronic warfare aircraft and is basically a specialized variant of the FA-18F Super Hornet and replaced the Grumman EA-6B Prowler in service with US Navy units.

The Ka-32 is the designation for the civil series of helicopters produced for the Soviet military forces under the designation Ka-25/27 and given the code names “Hormone” and “Helix”. Basically designed for anti-submarine warfare, the prototype appeared in 1981. Nikolai Ilytich Kamov was one of the lesser known Soviet designers