Walraven 2 и 4
Занимая с 1922 года должность главного инженера ВВС Королевской голландской ост-индской армии, Лоуренс У. Уолрейвен по собственной инициативе приступил к разработке и постройке легкого самолета. Машина получила обозначение Walraven 2 и представляла собой кабинный моноплан с двумя звездообразными двигателями Pobjoy Niagara. Самолет построили в единственном экземпляре.
Flight, February 1935
BUILT in the DUTCH EAST INDIES
The Walraven 2: Two Pobjoy Engines
DESIGNED by a Dutch aeronautical engineer, Mr. L. Walraven, and built at Bandoeng, in the Dutch East Indies, the Walraven 2 has a top speed of 156 m.p.h. and a landing speed of 40 m.p.h. It is an extremely interesting machine, and, if put into production, would be suitable not only for private owners but also for business people who, piloting themselves, wish to fly at high speed with two-engine security.
The designs were completed about a year ago, and the machine constructed during last year. It is powered with two Pobjoy “Niagara” engines, and is designed to have a long range - actually, 1,100 miles in still air. Two people are accommodated, seated side by side.
As can be seen from the photographs, the Walraven 2 is a low-wing, cantilever monoplane; the wings, of Gottingen 681 aerofoil section, are constructed with boxed spruce spars and spruce two-plex plywood ribs, the whole of the wing itself being covered with plywood. The low landing speed - 40 m.p.h. - is largely achieved by a flap across the trailing edge of the wing from engine to engine. The fuselage is monocoque, and of oval section.
Transverse frames are interconnected by longitudinal stringers and covered with plywood. The front portion of the fuselage is built up in one piece with the wing, but the rear portion is detachable at the rear wing spar. The tail units are very clean, the tail plane being of pure cantilever construction, and the rudder and elevators of duralumin, with fabric covering. The undercarriage is cantilever, fully faired, and has Palmer wheels and brakes.
The passenger seats are side by side on sliding mountings, and behind them there is a large luggage compartment, while there is also space for luggage in the nose.
This machine has been designed and manufactured throughout to conform to the Dutch East Indies Government requirements, and was constructed for Mr. Khom Kke Hien, a young Chinese.
Wing area 190 sq. ft.
WEIGHTS ANH LOADINGS.
Weight empty 1,380 lb.
Pilot and passenger 340 lb.
Fuel and oil 606 lb.
Baggage 103 lb.
Weight loaded 2,429 lb.
Wing loading 11.3 lb./sq.ft.
Power loading 13.5 lb.,h.p.
Max. speed 156 m.p.h.
Cruising speed 137 m.p.h.
Landing speed (with flap) 40 m.p.h.
Range 1,100 mile
Ceiling 00 one engine 8,000 feet.