Your feature `Electric aircraft on the horizon’ (23 June) was of great interest. However, I believe the claim that the A3XX `will become the first aircraft to specify an electrically-powered flight control system’ is incorrect.
The Vickers Valiant, the first of the trio of V-bombers made for the RAF, whose prototype first flew in May 1951, has claim to this distinction. The undercarriage alighting gear and all the main control surfaces were operated by electric actuators. The only hydraulic system in the aircraft -for the wheel brakes and nose wheel steering – was powered by electrically operated pumps.
Power was supplied by two systems, one operating at 110V DC and the other at 27.5V DC. They supplied the fuel pumps, undercarriage main and emergency motors, flaps main and emergency motors, air brakes motor, tailplane incidence fast and slow motors, bomb door motors, power control unit motors, inverters, the H2S scanner and three rotary transformers.
The controls were designed and supplied by the Boulton-Paul Company, which used the second prototype Vickers Tay Viscount, to develop and prove its systems.
This pioneering move by a British firm heralded the fly-by-wire flying controls now used in many of the world’s civil and military aircraft.
Neville J Mitchell, by e-mail
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