While some of the Articles of the 1944 Chicago Convention (see Appendix) relate both to the aircraft and to its pilot, this lecture is concerned with the aircraft and no attempt is made to deal with the problems connected with the licensing of pilots.

The opinions expressed are those of the author and not necessarily those of the Air Registration Board, or of the Ministry of Aviation on whose behalf the ARB attends ICAO Meetings. Nor is the theme of the lecture to be presumed to be accepted by the ARB or Ministry of Aviation.

A detailed consideration of the subject of the marine safety of helicopters leads naturally to the recognition that some helicopters are designed to be relatively “at home” on the water surface while some are not. In the former case, marine safety aspects will have a high degree of importance and priority from the commencement of the design, while in the latter, marine safety will be simply a matter of giving away as little payload as possible commensurate with obtaining a reasonable assurance of crew survival if a ditch takes place.

This paper sets out to consider some technical aspects of marine safety with both classes of craft.

In Part I of this series of papers, the development was described of a kW ion thruster for use as one of a set of primary propulsion units to be used for executing an orbit transfer manoeuvre. Both during the expansion phase, and when the final orbit is attained, micro-thrusters are necessary to provide attitude and position control of the satellite. This paper will describe two types of micro-thruster, each of which has particular merits and areas of use, so that the choice of thruster for a particular mission depends upon a fairly detailed specification of the mission. This consideration and broader system concepts will be dealt with in the final paper of this series (Part III).

It is not generally realised that the ground effect principle on which the air cushion vehicle is based was first expounded by a Scandinavian scientist some hundred years before Sir George Cayley grasped the basic principles of flight and two hundred and fifty years before the hovercraft went into commercial service. The basic principle of the air cushion vehicle is extremely simple, but, as in many branches of engineering, simplicity of principle and ease of achievement do not go hand in hand!

How does a hovercraft hover? Let us take a vehicle with a weight of 1000 lb (454 kg) and a flat undersurface of 100 sq ft (9m2) in area. If we increase the air pressure under the machine by 10 lb/sq ft (478 N/m2), the total reaction pushing upward from the undersurface of the machine will be 10 x 100 = 1 000 lb (454 kg). This, being equal to the weight of the machine, will cause it to leave the ground.

Professor A. D. Baxter opened the discussion and outlined how the 1964 Industrial Training Act had led to increased awareness of the need for trained and professional skill in management. The Central Training Council set up a Management Training and Development Committee, whose recent booklet “Management Training and Development” (HMSO) was the subject of discussion. There is now, for the first time, a national policy for producing better managers supported by financial sticks and carrots. It was the intention that this new move should lead to a massive scale of training of existing and future managers thereby improving managerial effectiveness, the usage of national resources and thereby the financial situation of firms and of the country.

During the evening no one criticised the national policy, except to say that it was expressed in such broad terms, in the form of a “child's guide”, whose benefits would depend, therefore, on how the policy was interpreted by the Industrial Training Boards. It was too early to say yet whether it would be well interpreted and resolve the special problems of highly technical industries such as aerospace.

In 1956 the Defence Research Board of Canada and Canadair Limited (a wholly-owned subsidiary of General Dynamics Corporation), agreed to sponsor jointly a study of V/STOL technology to determine the configuration of aircraft best suited to the support of ground forces. During the following year it was decided that for the transport role the tilt-wing/slipstream-deflection concept promises the best aircraft from the overall point of view. Subsequent analysis and flight experience have confirmed this, and have also demonstrated a high degree of compatibility between aircraft attributes and general requirements for support of surface forces.

It is only in fairly recent years that the idea of sending an object to another planet has become a practical reality. This has led to the rapid development of celestial mechanics, although the subject is by no means new. The purpose of the paper is to introduce the subject and to see how well-established results and equations may be utilised to find out about the motion of an object on its way to another planet. Once the path is determined, various deductions may be made about the rocket vehicle which must place the object or spacecraft along that path.

The concept at “launch window” will be introduced and a method of determining it will be presented. Once it is known, the number of available trajectories (although theoretically infinite) are narrowed down by selecting desired values of some parameters.