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Manuel Hawk

Hawk
Role Glider
National origin United Kingdom
Designer W.L. Manuel
First flight 25 November 1972
Number built 1

The Manuel Hawk was a homebuilt single-seat glider designed and constructed in the UK around 1970. Only one example was flown.

Design and development

W. L. "Bill" Manuel, who had designed and built a glider as early as 1929 and was later responsible for the Willow Wren, designed the Hawk during his retirement. It was a single-seat aircraft intended for soaring in weak thermals.[1] He built the Hawk himself during 1968 and 1969[2] before taking it to the College of Aeronautics at Cranfield for structural analysis.[1]

The Hawk was an all-wood, cantilever shoulder wing monoplane. The centre section of the three-piece wing was of constant chord and fitted with parallel-ruler type, upper surface airbrakes positioned at 28.26% of the half-span and at 42% chord. The outer panels were tapered with rounded tips and carried the ailerons. The wing had an angle of incidence of 3° and the outer panels had 3° of dihedral. Structurally, the wings had a spruce main spar at 33% chord with a plywood-covered torsion box ahead of it and fabric covering aft.[1]

The fuselage was a semi-monocoque spruce structure with plywood covering. The fin was also plywood-covered, carrying a fabric-covered rudder which reached from the underside of the T-tail to the bottom of the fuselage. The fixed-incidence tailplane was likewise plywood-covered and the elevator fabric-covered. The latter carried a Flettner-type trim tab on its starboard edge. The Hawk's single seat was forward of the wing and under a hinged, framed canopy. It landed on a single fixed wheel assisted by a tailskid.[1]

The first flight was on 25 November 1972, piloted by Howard Torode of the Cranfield Institute. Tests showed a lack of rudder power, quickly cured by an increase in area, but no other concerns.[1]

Operational history

Only one Hawk was built. It was certified as BGA 1778 by February 1973.[3] In July that year it was at the Sywell PFA weekend, where it gained third place in a competition amongst homebuilt aircraft.[4] Since 2013 it has been preserved by the Gliding Heritage Centre at Lasham.[5]

Specifications

Data from Jane's All the World's Aircraft 1973/74[1]

General characteristics

  • Crew: 1
  • Length: 20 ft 6 in (6.25 m)
  • Wingspan: 42 ft 0 in (12.80 m)
  • Height: 4 ft 8 in (1.41 m)
  • Wing area: 149 sq ft (13.8 m2)
  • Aspect ratio: 12
  • Airfoil: Wortmann FX6-184 inboard, FX-61-210 tip
  • Empty weight: 407 lb (185 kg) equipped
  • Max takeoff weight: 640 lb (290 kg)

Performance

  • Maximum speed: 91 mph (146 km/h, 79 kn) in smooth air. Like the following performance figures, this speed is for maximum take-off weight
  • Stall speed: 36 mph (58 km/h, 31 kn)
  • g limits: +4
  • Maximum glide ratio: best 25:1 at 41.5 mph (36 kn, 66.5 km/h)
  • Rate of sink: 152 ft/min (0.77 m/s) minimum at 38 mph (33 kn, 61 km/h)
  • Wing loading: 11.8 lb/sq ft (58 kg/m2) maximum

References

  1. ^ a b c d e f Taylor, John W R (1973). Jane's All the World's Aircraft 1973/74. London: Jane's Yearbooks. pp. 576–7. ISBN 0-354-00117-5.
  2. ^ Ellison, Norman (1971). British Gliders and Sailplanes. London: A & C Black Ltd. p. 142. ISBN 978-0-7136-1189-2.
  3. ^ "UK register". Air Britain Digest. 2 (4): 139. July–August 1973.
  4. ^ "Flying is Popular". Flight. Vol. 104, no. 3358. 19 July 1973. p. 92.
  5. ^ The Gliding Heritage Centre Collection