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Aviation History
1959
1959 - 1478.PDF
This drawing gives a clear indication of the layout of the ingenious Vickers missile; A, nose probe; B, hollow-charge warhead; C, warhead fuse; D, gyroscope assembly; E, solid-charge motor; F, control actuators; G, turbo-alternator; H, motor igniter, nozzle and flare; 1, main wire spool; K, subsidiary wire spool. Overall dimensions are: length, 33in; wing span, 7 Jin; body diameter, 4.5in with a cotton-lapped covering, and a very modest overall diameter. It was found that the blast of the rocket motor during the launch- ing tended to pull excessive quantities of wire from the spool, and a great deal of development was needed to overcome this tendency. The final type of spool has a sloping curved flank at the trailing edge and a surrounding shroud which constrains the wire to leave from a peripheral annular gap. In early rounds the motor igniter was located at the forward end of the blast pipe, but the final unit comprises a composite igniter, flare and nozzle which also incorporates radio-frequency filters. The igniter is fired following the satisfactory completion of the pre-kunch actions, and the thrust of the boost charge fires the missile with a high acceleration. As the motor nozzle heats up it ignites magnesium sprayed as a coating on to the rear part of the blast tube in order to provide a bright smoke-free flare. Origin- ally magnesium wire was employed for this purpose. The operator watches the flare through a monocular sight, and governs the flight of the missile through an articulated thumb- stick. It has been found possible to train operators very rapidly with the aid of a simulator, until; a high hit probability can now be achieved over a wide range-bracket. Uncontrolled test vehicles started their flight trials in the summer of 1957, and programme-controlled rounds were fired in July last year. The first firing of a command-guidance missile took place in September, since when the programme has pro- gressed rapidly. Probably the most important series of trials yet conducted have been those undertaken at Redstone Arsenal under an invitation from the U.S. Army. Considering that the missile had been under development only 2£ years Vickers regard these trials as successful, and they auger well for the missile's future prospects. At present there is a fairly clear divergence of opinion between those who believe in the concept of an infantry-operated anti- tank missile and those whose sole interest is in a much larger weapon fired from a vehicle and certain of killing any tank with one shot. The Vigilant is obviously a compromise between weight and killing power, but one type of hollow-charge warhead (there are alternatives) is believed to be as lethal as any other warhead of similar weight in the world. When well away from the launcher, the warhead is armed by a pressure switch and an inertia-timer. The round as a whole promises to become the most effective that can be carried into battle by one man. CRANFIELD'S NEW PARIS LAST December, it may be remembered, the College of Aero-' nautics at Cranfield took delivery of a Morane-Saulnier MS.760 Paris (two Turbomeca Marbores). Since then they have been putting it to good use. The first phase of special-instrument installation has been completed and students of the Department of Flight have started measuring performance characteristics. The second phase, to take place during the summer vacation, will complete the .instrumentation required for measurement of stability, control and manoeuvrability characteristics. The basic concept of the installation (reports the Department) has been to make provision for three students on each flight reading visually and trace-recording all the required quantities. The rear seats have a visual display of all steady quantities on micro- ammeters, any of 15 quantities being selected by a multi-position switch for each micro-ammeter. The latter can be read for steady-state tests or can be used for monitoring the recorder in transient tests. The student in the front seat has a small panel giving airspeed, height and air temperature and reads the engine instruments and flowmeters. The pilot's instrument panel has been redesigned to provide a blind-flying panel with Smiths V.S.I.; Kelvin-Hughes turn-and- slip indicator and altimeter; Speny artificial horizon and CL.1A Gyrosyn compass; Mechanism machmeter and K.D.G. (French) A.S.I. The radio installation at present consists of a Standard Radio STR.9 and Murphy MR60 V.H.F. set, but Murphy Rebecca Mk 8 will be fitted in Phase 2 of the instrumentation test. The instruments installed will cover all aspects of the teaching of flight-testing techniques. In the choice of instruments, emphasis has been placed on reliability and modern design. Elevator, tailplane, rudder, aileron and flap angles are measured by Penny & Giles linear potentiometers installed as near the operating surface as possible. Angles of pitch and roll are obtained from a potentiometer pick-off on a Ferranti FH.8 artificial horizon, which also acts as a stand-by instrument for flight. A pick-off from the Sperry CL.1A gives heading. Rates of roll, yaw and pitch are given by gyros (installed under the rear seat) respectively made by Colnbrook Instruments, the R.A.E. and Elliott Bros. Longitudinal and normal acceleration indication is by SFIM accelerometers. SFIM pendulum level, and height and airspeed capsules, are integral with the A. 13 recorder installed in the rear luggage compartment. Control of the recorder, giving fast or slow speeds and event marking, is done from the rear seats. Instruments to be installed in Phase 2 are: stick-force trans- mitter; strain-gauges for measuring rudder force; a miniature R.A.E.-type sideslip and pitch vane on a nose-probe pressure head; and air thermometer heads of the ventilated pitot and thermistor type. A traversing jet-pipe pitot is being designed for the measurement of engine thrust, in conjunction with thermo- couples and jet-pipe static pick-up. Further instruments are likely to be needed for thesis and research projects and will be installed as required, but the Phase 1 and 2 installation will allow students to complete a comprehensive series of flight experiments illustrating the principles of non- dimensional jet performance. During the present term measure- ments are being made of level speeds at altitudes of up to 25,000ft, as well as accelerated levels, range and drag rise with Mach number. This work is being done by students who are taking Minor Specialization in Flight Testing. At the same time, second-year Aerodynamics students are exploring the characteristics of stability oscillations, including the Dutch roll and the phugoid (or speed oscillation). Under certain conditions the latter is divergent, and —apart from giving the student a spectacular demonstration— permits important stability derivatives to be found. It is hoped that all the first-year students will have at least one flight during the term. The Paris has many features which make it ideal for teaching. The trimming tailplane can give much more information on the stability characteristics, as well as permitting strain-gauge measure- ments of loading; and the empennage configuration is interesting in view of the present-day trend in such civil aircraft as the VC.10 and D.H.121. An early test will be to establish strain levels on the fin during sideslips and lateral oscillations. The vibration inherent in piston-engined aircraft has hitherto prevented this type of work being done at the College. "Prospects in the stability field are delightful," adds the Depart- ment of Flight. "Fuel can be transferred from one tip tank at a time, so measuring aileron effectiveness. There are lifting points on the fuselage so that the aircraft can be suspended as a compound pendulum for measuring moments of inertia and, as already men- tioned, the normal flight oscillations are comparatively easy to measure." The reasons behind Cranfield's choice of the MS.760 have been several. The requirement was for an aircraft that would carry three or more students, have a generous flight envelope in terms of Mach number and g and yet have a piston-engine level of operating cost. The last point mitigates against the other two, as high thrust is expensive. Using a total of only 1,500 Ib sea-level thrust (with two-engine safety) cruising Mach number is 0.65, and 0.7 is reached in a gentle dive. Maximum g of 4.5 is quite sufficient for students trying to record stick-force per g.
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