| Short 31/26 | |
|---|---|
| Role | autogyro flying boat patrol aircraft |
| National origin | UK |
| Manufacturer | Short Brothers |
| Designer | Juan de la Cierva and Arthur Gouge |
| Status | Abandoned project |
The Short 31/26 was an unrealised [a] 1927 project to develop an autogyro flying boat to meet UK Air Ministry specification 31/26. [1] [2] [3] It is also known by its Cierva design number Cierva C.13 [2] or Cierva C.14. [1] [2] [3]
On 11 July 1927, the UK Air Ministry issued specification 31/26: Gyroplane boat seaplane (Jupiter engine). The specification called for "the design and construction of a three-seater gyroplane boat seaplane, embodying the principles of the La Cierva autogiro." [4]
The specification goes on to describe a flying boat with positions for a pilot, observer, and gunner. [5] The gunner was to sit in a forward cockpit and be armed with a Lewis gun mounted on a Scarff ring. [5] The aircraft was also to be able to carry twelve bombs that could be launched via an RL tube. [5] A 485-horsepower (362 kW) Bristol Jupiter VIII radial engine was specified for the powerplant. [6] The aircraft was to be capable of 100 miles per hour (160 km/h) and have a stall speed not greater than 40 miles per hour (64 km/h). [7] In addition to its rotor, it was to have fixed wings. [8] [9]
Development was conducted in partnership between Juan de la Cierva and Short Brothers chief designer Arthur Gouge. [2] [3] A two-bladed [2] [b] main rotor was chosen, to be fitted on a pylon above a metal hull. [2] [3] Sponsons were to be fitted for stability on the water. [2] [3]
A model was constructed and tested in the Short Brothers tank at their Rochester factory, but development progressed no further. [1] [2] [3] The experiments showed problems with vibration, [1] [3] which aviation historian Peter W. Brooks notes "would almost certainly have proved unsuperable at this period." [2]
Data from Air Ministry 1927, and as noted
General characteristics
Performance
Armament