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HAWKER SIDDELEY'S studies on future advanced aircraft embrace the complete spectrum of field length from CTOL down to VTOL. However, this review is concerned solely with the results and conclusions obtained from past studies undertaken in 1969–1971 of STOL and V/STOL aircraft to meet requirements in the longer term.

British Aircraft Corporation is developing a new generation quiet (Q) jet airliner with an impressive short take‐off and landing (STOL) capability to overcome the growing environmental problems and congestion in short‐haul inter‐city and inter‐urban air transport.

Because it is a small, mobile service that must make the most of every asset, the Marine Corps in the 1940s and early 1950s began to use the utility helicopter as a weapon system. Very quickly it became obvious that the “chopper” offered Corps commanders unprecedented flexibility in moving ground forces much faster than by surface transportation.

TYPICAL STOL CHARACTERISTICS can be achieved for medium and heavy jet transport aircraft by means of externally blown flaps. As part of a project study conducted by Dornier AG., concerning a 40t STOL transport aircraft, the aerodynamic and flight mechanical feasibility is demonstrated. The basic data was supplied by wind tunnel tests with the model of a transport aircraft. With a view to V/STOL capability, the engine jet deflection was optimised by means of a novel slot flap design on a simple rectangular wing.

Effective explicit algorithms for integrating complex elastoplastic constitutive models, such as those belonging to the Cam clay family, are described. These automatically divide the applied strain increment into subincrements using an estimate of the local error and attempt to control the global integration error in the stresses. For a given scheme, the number of substeps used is a function of the error tolerance specified, the magnitude of the imposed strain increment, and the non‐linearity of the constitutive relations. The algorithms build on the work of Sloan in 1987 but include a number of important enhancements. The steps required to implement the integration schemes are described in detail and results are presented for a rigid footing resting on a layer of Tresca, Mohr‐Coulomb, modified Cam clay and generalised Cam clay soil. Explicit methods with automatic substepping and error control are shown to be reliable and efficient for these models. Moreover, for a given load path, they are able to control the global integration error in the stresses to lie near a specified tolerance. The methods described can be used for exceedingly complex constitutive laws, including those with a non‐linear elastic response inside the yield surface. This is because most of the code required to program them is independent of the precise form of the stress‐strain relations. In contrast, most of the implicit methods, such as the backward Euler return scheme, are difficult to implement for all but the simplest soil models.

The experience gained since 1959 at MBB, Military Aircraft Division, in the development and flight testing of V/STOL combat aircraft having the capability to reach Mach 2 and to take off with after‐burning temperatures is described. The German project VJ 101 C and the US/FRG project AVS as well as the joint US/FRG V/STOL Technology Programme conducted during the years 1967 through 1970 serve as examples. The paper consists of two main sections:

The urgent need for decisions on new programmes is emphasised by Sir Richard Smeeton, Director of the Society of British Aerospace Companies. “With such aircraft as the supersonic Concorde and the V/STOL Harrier we can truly claim to be ahead of all competition. But, particularly in STOL and V/STOL, our lead is being steadily whittled away and, unless action is taken on firm projects soon, it will stand in danger of being lost altogether.” Sir Richard continues: “At the same time governments of other countries, such as France, Germany and Japan, are showing a strong awareness of the need to expand their technological standing by offering increasing support to long‐term development of their aerospace industries”.

THE Lockheed‐Georgia Company's High Technology Test Bed (HTTB) aircraft — which already holds three STOL (Short Takeoff and Landing) time‐to‐climb world records — has entered the modification hangar for its most ambitious enhancement to date … changes that will enable it to land at a speed of ‘arond 80 knots’ and to require no more than 1,500 feet of runway.

GIVEN by Dr John Fozard of British Aerospace, who was Chief Designer, Harrier, 1963–78, this paper formed part of the presentation on shipborne V/STOL aircraft held recently at the Royal Aeronautical Society. Dr Fozard reviewed the effects of Harrier jet V/STOL on an evolving world defence scene in the past 20 years. In naval aviation, the advent of the jet aircraft and swept wings forced other developments such as the angled deck and the mirror sight. Large carriers were essential with costs also very high. On the other ‘side of the fence’, jet V/STOL was just beginning with the first P 1127 making its first cautious hovers in 1960. It was developed in the next few years and made the first flight from a carrier of this kind of aircraft. Changing naval fortunes made it policy at one time that tactical air power at sea would be provided by land based aircraft. Later, this began to be overturned and studies were made of smaller carriers, thought they were called ‘through deck cruisers’ or some similar name, for a variety of reasons.

SINCE 1955 BERTIN & CIE has been engaged in research and development of solutions in relation to problems of short or vertical take off. Alone or with the collaboration of other working teams the company has conducted a number of actions in different directions and among other results has designed the ‘Variflux’ variable geometry wing incorporating a number of elementary profiles each pivoting around an axis.