To save money, the Airco DH.9A was adapted from part completed airframes, available in large numbers following the end of the First World War and the cancellation of orders.

[2] Further development was passed on to Westland, who further modified the aircraft to produce the Walrus, with a 450 hp (336 kW) Napier Lion II engine replacing the Liberty engine of the DH.9A and Tadpole.

[3][4] The prototype first flew in early 1921, proving to have poor flying characteristics, being described by Westland's test pilot Stuart Keep as "a vicious beast" but despite this, a further 35 were ordered.

3 Squadron was split up to form independent Fleet Spotter Flights in 1923, although despite the extensive navalisation, the Walrus never operated from carriers.

[6] Data from Westland Aircraft since 1915 [7]General characteristics Performance Armament