A deliberate product strategy is usually aimed at creating a transport aircraft family on the basis of a common wing by stretching the fuselage. Due to this policy of high fleet commonality the costs for development, manufacture and maintenance can be reduced. On the other hand the wing designer has to choose an appropriate wing area for the maximum stretched version and try to find the best trade-off between design and off-design conditions.

A transonic wing however shows optimum performance at high loadings which are not achieved at entry into service with such a conventional fixed geometry wing. Variable Camber (VC) is offering an opportunity to achieve considerable improvements in operational flexibility, buffet boundaries and performance which allow a reduction in optimum wing size.

Significant drag reductions and increases of the buffet boundary were found from research work. This work led to the current concept where the trailing edge flaps and ailerons are used to modify the wing camber in cruise according to the lift demand.

An efficient VC system requires a change in design philosophy and several new constraints in the design problem were found to effect the extent of the supersonic region, the acceptable pressure gradients in the recompression zone and the required surface curvature. Theoretical and wind tunnel results are given as well as a discussion of the effects on the system design, loads, weight, handling qualities, propulsion integration and mission performance.

Variable camber will contribute an average reduction of 3 to 6% in fuel burn and enable the use of one wing for medium range and long range missions respectively. The introduction of VC will launch a new generation of intelligent airliners which will optimise their camber schedule throughout the entire mission. A further improvement potential due to leading edge camber devices and spanwise differential camber is emphasised.

A finite element analysis has been carried out to simulate the effect of birdstrike on concave curved metal stiffened panels representative of engine intakes. A simplified static analysis approach was adopted including the effects of non-linear material response and large displacements. Loading was by means of an equivalent pressure derived from experimental results of bird impacts on rigid plates. Good agreement was obtained between predicted and measured bird impact velocities to cause penetration of the structure for a range of panel thicknesses, curvatures and impact angles.

In 1989, more than 29 million passengers were flown across the North Atlantic Ocean in 167 000 scheduled and non-scheduled flights. At peak times during the Summer months, a trans-Atlantic flight was crossing the Shanwick Oceanic Control boundary every minute and more than 200 flights were reporting between 10 and 50 degrees West. Traffic counts exceeded 750 flights a day.

The following account describes the more recent improvements to North Atlantic air traffic control, the early introduction of computers to the task, with their on-line data interchange between Oceanic Control Centres and the current computer supported services provided by the Shanwick and Gander Oceanic Area Control Centres.