The first major production model was the IIID, which was an improved IIIC, with provision for a third crewmember and capable of being fitted with either a floatplane or a conventional wheeled undercarriage [REF].
The most prolific and enduring of the Fairey IIIs was the final model, the IIIF, which was designed to meet Air Ministry Specification 19/24 for a three-seat spotter/reconnaissance aircraft for the Fleet Air Arm and a two-seat general purpose aircraft for the Royal Air Force.