During development the Wyvern killed three test pilots, Penrose almost became the fourth to succumb to this potentially lethal beast.

Penrose’s bursts of crazy flying in Widgeon G-AAGH will never be forgotten by those who watched his hilarious performances.

Penrose made the first flight of the Westland Whirlwind in October 1938.
The Westland Whirlwind was designed to Air Ministry Specification F.37/35, issued in February 1936, for a cannon-armed single-seat day- and night-fighter predominantly for home defence, and had speed and fierce firepower at the heart of its design; the four 20mm cannon in the nose were for knocking down unescorted bombers.

Harald Penrose seated in the cockpit of the twin-engined Westland Whirlwind (Welkin ???) fighter.

Using the same configuration as the Whirlwind, the Welkin was too late to see war service.

The Pterodactyl Mk IV, K1947, was initially flight-tested by L. G. Paget but development flying was continued by Penrose and F. J. Brunton.