The Piper PA-31 Navajo is a twin engine aircraft powered by Lycoming engines designed for the general aviation market.

In the mid-1960s company founder William T.Piper started development of the PA-31 to meet the demands of small-scale cargo and feeder liner operators and also the corporate market.

The first flight was made on 30th September, 1964. The design proved a great success with 2044 aircraft being produced.

The Piper Navajo Chieftain variant saw service with the Royal Aircraft Establishment at Farnborough, replacing their fleet of De Havilland Devon aircraft in the light transport role, along with the Armament & Aircraft Experimental Establishment (A&AEE) at Boscombe Down, Wiltshire. The RAE aircraft wore the serials ZF520 to ZF522 and were later sold on the US civil market in the late 1990s. ZF622 still soldiers on with QinetiQ at Boscombe Down.