FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1961
1961 - 1220.PDF
322 FLIGHT, 31 August 1961 "Vibrashock-lsolation" mounting, showing resilient element of stainless-steel wire (Delaney Gallay Ltd.) NEW from the ACCESSORY INDUSTRY and reliable nosewheel-steering mechan-ism for use during taxying and to provide optimum control during take-off or land-ing. The pilot control is a resistance transducer, which is coupled to a follow-up transducer on the nose undercarriage in the form of a simple Wheatstone-bridge circuit polarized from a d.c. supply. A transistorized amplifier formsa sensing element, operating slave relays in response to error signals. The systemis completed by a control panel and any suitable type of steering motor. Thesystem can be adapted to have widely varying characteristics suitable for newor existing aircraft, and provides precise control without backlash or hysteresis. Dowty-Rotol Ltd The Dowty Group'soutstanding technical and material re- sources have enabled Dowty-Rotol toacquire a leading position in the field of hovercraft lift-fans. In certain circum-stances the centrifugal impeller has been found to be superior, and most of thecompany's work has concentrated upon such designs; but during the last twoyears considerable effort has been applied to the development of fixed- and variable-pitch axials. Prime requirements for all units are minimum weight and cost, flathead-flow characteristics, high efficiency and long life. The Dowty-Rotol centrifugal impellersare made of glass-fibre and steel, the blades being attached to a spoked centralwheel to give a light and rigid structure. All normal damage has been foundeasily repairable, and light stainless-steel sheathes minimize erosion and the con-sequences of stone impact. The results of extensive rig testing and operationalemployment have indicated the suitability of these fans for use in ground-effectvehicles. Most work has been done on 3ft and 6ft fans, but designs are nowunder construction absorbing up to 1,300 h.p. in a diameter of up to 12ft. Another entirely new development isa hydraulic vibration system, which not only gives a clean waveform over a widerange of frequencies but is also con- sidered to be the cheapest possiblearrangement for fatigue testing. Cheap- ness is particularly marked when highthrusts are demanded in the frequency range below lOOc/s. An existing modelcan impart a total force of 50,0001b with a preload of 25,0001b. These vibratorscan operate at any predetermined fixed frequency, or they can be controlled bya tape or other variable input. Dunlop Rubber Co Ltd The company'saviation division has collaborated with the Royal Aircraft Establishment, Bed-ford, in the latter's design and develop- ment of runway arrester-gear. Thesystem—which is to be demonstrated full-scale at Farnborough after the flyingdisplays—is intended to handle aircraft of up to 50,0001b landing at speeds ofup to 130kt, and will bring them to rest within 600ft. A reserve of stoppingpower is available to deal with even higher weights and speeds. A cable stretched across the runway isattached at each end to a nylon webbing band wound round the horizontallymounted drum of an energy-absorbing installation incorporating a Dunlopmulti-disc friction brake. When an alighting aircraft engages the cable, thecontrolled braking power supplied by the two energy-absorbing installations de-celerates the aircraft at a constant and predetermined rate. In permanent instal-lations the mechanical units are partly Brushless a.c. generator for 55kVA variable- frequency system now in production by the English Electric Aircraft Equipment Division below ground, but in the case of trans-portable field units they are mounted on steel frames anchored to the ground. Dunlop are also supplying equipmentfor runway arrester-gear developed abroad. In addition to their aircraft tyres,wheels and brakes, the company's exhi- bits at Farnborough will include amotor-driven brake cooling fan (as used on the DH Trident), thrust-reversalequipment for Rolls-Royce Conway and Spey engines, reheat components, pres- sure switches and reducing valves, andcontrol units for missile rocket motors, of which the Bristol Siddeley Stentor forBlue Steel is an example. English Electric Co Ltd During thepast year the company's Aircraft Equipment Division has developed anew, compact 30kVA constant-frequency generating system. A single channelconsists of only four units: constant- speed drive, brushless generator, com-bined static control and protection unit, and a contactor. The current trans-formers of the Merz-Price system are mounted in the generator block and onthe bus-bar. The complete channel weighs only 1791b. The 38 h.p. drive in this system andthe 50 h.p. drive now specified for the Vickers VC10 both benefit in design andconstruction from experience with the English Electric drive currently in serviceon BOAC and Air-India Boeing 707s and on the V-bombers. Also developed during the past yearis a 55kVA variable-frequency system. Now in production, it consists of abrushless a.c. generator, a circuit breaker and a control and protection unitembodying semiconductors and printed circuits. An oil-cooled brushless a.c.generator is also being produced in quantity for the Mk 2 Victor constant-frequency system, and a single-phase 400c/s a.c. rotary actuator developed forthe VC10 is now being delivered. Being shown at Farnborough for thefirst time is the new single-unit constant speed drive, of a type which has alreadycompleted l,600hr in airline service. Of the 15m hours flown by American andBritish-built Sundstrand constant-speed drives, 180,000hr have been completedby the drives made by English Electric. The Fairey Company Ltd Some of themost important aviation activities of the Fairey Group of Companies are discussedin the "Missiles and Targets" section on an earlier page. Powered flying controlsfrom the hydraulics division of Fairey Engineering Ltd are being produced for awide range of aeroplanes, helicopters and VTOL aircraft, and the division claim-to have "made more hydraulic power control units than any other company inthe world". In addition to systems for such familiar machines as the Trident,Belvedere, Hunter, Fiat G.91, Scimitar, Canberra PR.9 and Gannet, Fairey makepower controls for the Rotodyne, Hawker P.I 127, Hindustan HF-24 and the newHunting 126 jet-flap research aircraft. The hydraulics division also producespecial microfilters for aircraft, missiles and industrial applications. Siebe, Gorman & Co Ltd are now partof the Fairey Group. Among their newly developed products are a self- Godfrey gearbox compressor for Vickers VCI0
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
