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SAND is very harmful to engines. During recent tests conducted by me in the North African Deserts, as much as half a pound of sand has been collected in ten minutes in each air intake of a Mosquito aircraft taxying, alone, downwind on a desert airfield. Had the Mosquito been following another aircraft, or had its air intake been situated lower, the quantity of sand would have been much larger. Under such conditions the importance of having efficient air cleaning intakes fitted to every aircraft engine is obvious. Sandy conditions are not confined to desert airfields, some airfields in this country and on the Continent are as bad.

Smiths Industries is to supply the head‐up display system for the Sea Harrier. The company will design, develop and make the electronic head‐up display and weapon aiming computer system for the latest version of the HS Harrier which will operate from Royal Navy ships.

Aerodynamic characteristics of engine side air intakes for a lightweight helicopter are investigated aiming to achieve an efficient engine airframe integration.

On a novel full-scale model of a helicopter fuselage section, a comprehensive experimental data set is obtained by wind tunnel testing. Different plenum chamber types along with static side intake and semi-dynamic side intake configurations are considered. Engine mass flow rates corresponding to the power requirements of realistic helicopter operating conditions are reproduced. For a variety of freestream velocities and mass flow rates, five-hole pressure probe data in the aerodynamic interface plane and local surface pressure distributions are compared for the geometries.

In low-speed conditions, unshielded, sideways facing air intakes yield lowest distortion levels and total pressure losses. In fast forward flight condition, a forward-facing intake shape is most beneficial. Additionally, the influence of an intake grid and plenum chamber splitter is evaluated.

The intake testing approach and the trends found can be applied to other novel helicopter intakes in early development stages to improve engine airframe integration and decrease development times.

THE greater part of the development of the components of a complicated mechanism, such as an aircraft engine, can with advantage be done apart from the mechanism as a whole. The study of any part can be more complete and improvements in operation effected more readily when it is not necessary to keep the whole working. A carburettor is in many respects a complete unit whose action may be studied with advantage apart from the engine with which it will be used. While the ultimate criterion of the performance of a carburettor is its behaviour on an engine, a great deal can be learned from suitable bench tests in which the engine is replaced by a suction plant; more use could be made of such testing methods than is done at present.

ON aircraft operating in the rarefied atmosphere at high altitude, the idea of supplementing the air consumed by the engine with extra oxygen would seem to be a logical and desirable development, because the power output of a reciprocating engine is a direct function of the oxygen content of the air charge, provided that all the oxygen is burnt in the cylinder. However, the normal and most satisfactory line of development has been to fit the aircraft with engines of increased capacity or supercharge, so that the oxygen content of the air charge is increased simply by increasing the total mass of air consumed by the engine.

THE Bristol Siddeley Viper 520 turbojet engine which powers the de Havilland DH 125 jet executivc aircraft, employs an eight‐stage axial compressor which is driven by a single‐stage turbine. The combustion chamber is of the annular vaporizing type. Two Viper 520 engines are mounted in nacelles attached to the rear fuselage of the DH 125 such that the intakes are clear of the fuselage boundary layer at this position. Maximum take‐off thrust of the engines is 3,000 lb. for a specific fuel consumption of 0·985 lb./lb. thrust/hr.

THE following article is an attempt to provide those unfamiliar with the subject with a review of the working principles and the reasons for the use of so‐called ‘injection’ carburettor equipment, which has in recent years come to replace the conventional suction carburettor on reciprocating aero engines. As an introduction to the arguments, to be developed later, it is necessary to state a few simple definitions of the basic requirements for any form of carburettor for use on these engines.

THE B.A.C./Sud Concord supersonic airliner which was the subject of an official agreement signed by Mr Julian Amcry, the British Minister of Aviation, and His Excellency M. GcoiTroy dc Courccl, the French Ambassador, on November 29, 1962 , will be powered by four Bristol Siddeley Olympus Mark 593 turbojets. These engines are being developed and manufactured jointly by the Societe Nationale d'Etude et de Construction de Moteurs d'Aviation (S.N.E.C.M.A.) and Bristol Siddeley Engines Ltd. While Bristol Siddeley Engines will be responsible for the actual engines, S.N.E.C.M.A. is developing the reheat system, final nozzle and thrust rcverscr.

The Aviation Division of the Dunlop Co. Ltd. (Engineering Group) is to install Dynex power units, designed and built by Applied Power (U.K.) Ltd., in the latest design of hydraulic production test rigs at the Division's Coventry factory. The company is completely re‐equipping its production test facilities by providing every rig with the higher pressures and flows which future trends in fluid technology will demand, and to ensure that each testing station is capable of handling service fluids currently in use, including kerosene, DTD 585, Skydrol, Lockheed 22 and Oronite.

At present, intensive preliminary technological work is being carried out in the Federal Republic of Germany on the development of a new tactical combat aircraft (TKF). Among others, a research project is being carried out on behalf of the Federal Ministry of Defense on the design of engine air intakes for supersonic aircraft, in which Dornier and the German Aerospace Research and Testing Establishment (DFVLR) are participating.