The target world like Gaul is divided into three parts, namely:

• Converted aircraft

• Specially developed pilotless drones

• Towed targets

and I propose talking about these three types in turn.

The only converted manned aircraft in use in the UK is the Meteor U.16. This is a conversion of the Meteor F.8. The main structural change is the extended nose which houses the necessary black boxes, e.g. Autopilot, Control Radio Receiver, Telemetry transmitter, etc. By this means the aircraft can be flown with a pilot in the cockpit in the conventional way for non-firing runs or alternatively as a safety pilot when checking out the drone system.

The Stiletto is an air launched supersonic target developed for UK ranges. It is based on the American AQM 37A target which was designed and manufactured by Beech Aircraft.

The development programme has entailed a number of changes, both in equipment fit and control, on the target and the design and incorporation of a launching system into a Canberra aircraft. The programme has been a joint one between MoD as the customer and Shorts as co-ordinating design authority with collaboration from Beech and from the UK companies who developed and supplied the required equipment. The AQM 37A Target is purchased by Shorts from Beech, the necessary changes and additions made at Belfast and the resulting Stiletto target is delivered to RAE, Llanbedr. The development contract was placed late in 1966 and the first Stiletto was launched on programme on 1st August 1968.

While the development of the Turana drone forms a short and well defined programme, such programme would not have been possible without the preceding Australian activity on drones and guided weapons.

It might be appropriate to outline briefly this activity, since the approach to various problems of Turana and the solution of certain difficulties depended on the experience gained with the Jindivik, Malkara and Ikara.

In the year 414 before Christ a play was produced in Athens in which Aristophanes described how the birds who wished to build a free city in the air beat off the legislators who came to offer their services. Commenting on this event in an article published 17 years ago, I suggested that, if Aristophanes could look at the situation in the air at that momentand see in what way the legislators had prevented the birds of that dayfrom unfolding their wings, he would have prided himself on his foresight.

Transatlantic travel has entered a new era, the era of mass tourism. Low cost, newly available air charter services have made it possible. Their far-reaching benefits, economic, cultural, and educational, are now widely recognised and enjoyed on both sides of the Atlantic.

For more and more people lower travel costs are awakening a latent demand. For those who have tasted the benefits of low cost travel there can be no turning back. Low cost charter availability is taking on the character of a right which governments are increasingly being expected to protect and promote.

While my own views are the product of long association with the airline industry, I would not wish to ask the airlines—or any one of them—to assume responsibility for such personal views and conclusions as may be put forward in this paper. Having added this caveat, I am hopeful that what I have to say reflects at least the opinion of some within the airline industry.

The force on a circular cylinder inclined to a uniform flow may be resolved into three components, one perpendicular to the plane defined by the axis of the cylinder and the upstream velocity vector (described in this report as the out-of-plane force) one within this plane and perpendicular to the axis (the in-plane normal force) and one within this plane and along the axis (the in-plane axial force).

It has become common practice, since Allen and Perkins, to model the flow over a circular cylinder inclined to a uniform flow by resolving the incident flow into two perpendicular component flows. One flow is taken to be parallel to the axis of the cylinder (axial flow) and the other normal to it (cross flow). The cross flow is not taken to be uniform over the whole length of the circular cylinder. Instead it is considered to be started impulsively at the nose and to develop over the length of the body in the same way that the impulsively-started flow over a cylinder develops with time.

The rolling up of the vortex sheet shed from a finite aspect ratio wing into discrete vortices has been extensively investigated in the past. Most of these investigations have, however, considered wings having an elliptic loading.

The early design charts of Silvertstein et al gave downwash angles for a variety of flapped and unflapped aerofoils by considering the trailing vortex sheet to be composed of discrete line vortices but ignored the rolling up process that takes place.