SHORT S.31
- After receiving orders for two prototypes and 100 production aircraft
to the S.29 design which became the Short
Stirling, Shorts built in 1938 a '/2-scale prototype at its own expense.
Powered by four 90 hp Pobjoy Niagara III engines, this Short S.31 was mostly
of wooden construction apart from a semi-monocoque fuselage, and seated
two in tandem. In overall silver finish and marked M4, the Short S.31 flew on
September 19, 1938, at Rochester. It later acquired a lengthened u/c (as
adopted meanwhile on the Short S.29 to give greater effective wing incidence
during take-off and landing); then in January 1939 it was fitted with
115 hp Niagara IVs and in March with a larger tailplane. In 1940, now
in green/brown camouflage with yellow undersides, the Short S.31 was fitted
with Va-scale mock-ups of the Boulton Paul Type O ventral and Type H dorsal
twin-cannon turrets proposed for a version of the Stirling II, and was
tested in the RAE 24 ft (7.3 m) wind tunnel. Further flights were made
from March 13, 1942, onwards (with a shortened u/c), and the Short S.31 was
scrapped after a takeoff accident at Stradishall in February 1944. Max
speed, 180 mph (290 kmlh). Gross weight, 5,700 Ib (2,586 kg). Span, 49
ft 6'h in (15.09 m). Length, 43 ft 7'h in (13.31 m).
