In 1968 the Cavalier Aircraft Corporation modified two P-51 Mustangs with Dart engines in an attempt to interest the USAF in a lightweight counter-insurgency aircraft but having failed to do so, sold the design to Piper in 1979 who instead used the YT-55 turboprop in the two Enforcers they built. Despite looking like the Mustang, there was less than 10% commonality. First flown in 1983, the concept was successfully demonstrated but again no orders were forthcoming.

Initially developed by Cavalier Aircraft as the Turbo Mustang III. Renamed as the 'Enforcer', the project was sold to Piper in 1970 and two Mustang airframes (one single and one two seat) were converted with the addition of Lycoming YT55-L-9A turboprops. No orders were forthcoming and it wasn't until 1979 that Piper secured funds to construct two completely new build aircraft as Pa48 Enforcers. Although evaluated by the USAF, the aircraft were owned and operated by Piper and received no military designation or serials. Despite performing well in their role, no orders were ever placed.

One of a pair of new-build aircraft constructed by Piper for evaluation for the USAF. Not visible here, it carries the USAF star-and-bar on the fuselage.