 Short SB4 Sherpa The Short Sherpa was an experimental wing research aircraft, designed to test the flight characteristics of the 'aero-isoclinic' wing. Image File history File links Short_SB4_Sherpa_crop. ...
Image File history File links Download high-resolution version (1154x624, 52 KB) Scanned in from the manufacturers promotional/house publication Shorts Quarterly review, Vol. ...
Image File history File links Download high-resolution version (1154x624, 52 KB) Scanned in from the manufacturers promotional/house publication Shorts Quarterly review, Vol. ...
Short Brothers, almost universally referred to simply as Shorts, is a British aerospace company now based in Belfast. ...
History
Design (This text is derived almost entirely from the article referred to in the bibliography)
The Sherpa (not to be confused with the transport aircraft, developed from the Short Skyvan, which was given the same name in the United States) was designed by David Keith-Lucas as a research aircraft aimed primarily at assisting in the development of wings for faster, very high altitude aircraft. It was the first aircraft to employ the 'aero-isoclinic' wing first proposed by Professor G.T.R.Hill in 1951. This was designed to maintain a constant angle of incidence regardless of flexure, by placing the torsion box well back in the wing so that the air loads, acting in the region of the quarter-chord line, have a considerable moment arm about it. Construction was largely of spruce with plywood covering and light alloy components at strategic points. Sweep-back on the leading edge was just over 42°, to facilitate low-speed research. The torsional instability and tip stalling characteristics of conventional swept wings were recognised at the time, together with their tendency to aileron-reversal and flutter at high speed. It was to prevent these effects that the aero-isoclinic wing was designed. In the Sherpa the wing, which is used without a tailplane, is fitted with rotating tips (see the photos/illustrations) comprising approximately one-fifth of the total wing area. These were rotated together (to act as elevators) or in opposition (when they acted as ailerons). They were hinged at about 30% chord and each carried, on its trailing adge, a small anti-balance tab, the fulcrum of which could be moved by means of an electric actuator. It was expected that the rotary wing tip controls would prove greatly superior to the flap type at transonic speeds and provide greater manœuvrability at high altitudes. Denis Howe David Keith-Lucas CBE (born 25 March 1911, died 6 April 1997) was an aeronautical engineer. ...
 Image File history File links Short_Sherpa_wingtip_from_above. ...
Image File history File links Short_Sherpa_wingtip_from_below. ...
Handling Characteristics "The Sherpa's first trials, with Shorts' Chief Test Pilot Tom Brooke-Smith at the controls, ... proved very satisfactory and the small black and silver plane has been quoted as being 'one of the most graceful aircraft now flying'."
Specifications
General characteristics - Crew: one
- Length: 31ft 10.5in ( m)
- Wingspan: 38ft ( m)
- Height: 9ft 1.12in ( m)
- Wing area: ft² ( m²)
- Empty: lb ( kg)
- Loaded: lb ( kg)
- Maximum takeoff: 1 lb ( kg)
- Powerplant: 2x Blackburn Turbomeca Palas turbo-jet, each 350 lb thrust ( MW)
Performance - Maximum speed: mph ( km/h)
- Range: mi ( km)
- Service ceiling: ft ( m)
- Rate of climb: ft/min ( m/min)
- Wing loading: lb/ft² ( kg/m²)
- Power/Mass: hp/lb ( kW/kg)
Armament
Related content Related development:
Comparable aircraft: none
Bibliography - Sherpa - fore-runner of high speed, high altitude aircraft, article in Shorts Quarterly Review, Vol. 2, No. 3, Autumn 1953
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