SHORT S.20 and SHORT
S.21 - Composite
aircraft pair conceived in accordance with patents by Major Mayo and supported
by Air Ministry and Imperial Airways, to provide a heavily-loaded mailplane
with transatlantic range. Under Specification 13/33, Shorts designed a
variant of the Empire flying-boat (see S.23 entry) as the carrier (Short
S.21) of a small two-seat seaplane (Short S.20). Powered by four 900 hp
Bristol Pegasus XC engines, S.21 G-ADHK Maia first flown on July 27, 1937;
powered by four 340 hp Napier Rapier Vs, Short S.20 G-ADHJ Mercury first
flown September 5, 1937; and first combined Short S.20/ Short S.21 flight
on January 20, 1938. After outbreak of war, Short S.20 Mercury used for
training, including a spell with Fokker T-8-W-equipped No 320 (Netherlands)
Sqn at Pembroke Dock, until returned to Rochester and scrapped late 1941.
Short S.21 Maia used by BO AC for training at Poole until destroyed in
enemy air raid on May 11, 1941.
Data for Short S.20: Max speed, 212 mph (339 kmlh). Range, 3,900 mis (6,240
km). Gross weight, 20,800 Ib (9,443 kg). Span, 73 ft 0 in (22.2 m). Length,
51 ft 0 in (15.5m).
Data for Short S.21: Max speed, 200 mph (322 kmlh). Range, 850 mis (1,360
km). Gross weight, 38,000 Ib (17,252 kg). Span, 114ft (34.7m). Length,
84ft 11 in (25.9m).
