An extensive experimental investigation into the nature of the wall jets produced by single and twin normal jet impingement has been undertaken. Wall jet velocity profiles have been recorded up to 70 jet diameters from the impingement point, at pressures representative of current VStol technology. The tests used fixed convergent nozzles, with nozzle height and spacing and jet pressure being varied. Single jet impingement displays a consistent effect of nozzle height on wall jet development. For twin jet cases a powerful reinforcement exists along the wall jet interaction plane. Remote from the interaction plane the wall jets are weaker than those produced by a single jet impingement.

Aircraft plying between urban and outlying communities usually enjoy a runway with noise restrictions at the urban end and perhaps little to land on at the other end, but with no objection to noisy operation. The existence of this situation in northern Canada persuaded the National Research Council to embark — some thirty years ago — on an investigation of powered lift possibilities, with strong support from the trunk and regional airlines, the charter and helicopter operators, and various manufacturers.

From a number of generic lift-propulsion arrangements examined in greater or lesser detail, a selection are described here in increasing order of what the certifying authorities call “damage tolerance” or reduced dependence on “critical parts”. Freedom from demands for hovering endurance and quietness, combined with emphasis on small aircraft, offered encouragement to attack what is otherwise a very difficult task. Of the alternatives, only one, which incorporated transverse axis fans and the light weight gas turbines now available, emerged as a potentially satisfactory choice for small rugged transport aircraft.

The project was discontinued because of pressure of other work, but is recounted here in case others may discern wider market possibilities. A small Vtol aircraft should, if successful, be a useful precursor to sophisticated airliners capable of taking off and landing without a run.

Shells, stability under various types of loadings and their combinations have not yet been completely investigated. This is due to incomplete knowledge of shell philosophy. The aim of this study is to provide a complete and integrated method for treating shell problems on a pure statical basis. This study introduces shell orthotropic behaviour, discusses hoop stress resultant actions, and applies the shell equilibrium equations to a uniaxially compressed cylindrical shell with finite length and fixed ends. Theoretical results are also compared with previously published experimental work. The behaviour of shells in elastic and plasto-elastic range is discussed for a wide range of shell geometries (dimensions), material properties, methods of manufacture, material imperfections, and methods of load application. From this study we conclude mainly that shells behave orthotropically. Their flexural rigidities are related to their radii of curvature and the resultant buckling mode. The buckling strength of a shell depends on shell geometry, material properties, buckling mode and shell coefficient H. This shell coefficient is affected by the method of manufacture, existing imperfections, degree of plasticity, and the method of load application. H can be evaluated by experiment.

The permanent urgency of aircraft design during the author’s career at Hawker Aircraft, a.k.a. British Aerospace Kingston, inhibited publication of his advances of theory. So he collected those on propulsion and presented them to the Royal Aeronautical Society in a lecture “Some Unpublished Contributions to Propulsion Theory” on 11 March 1992. The meeting proposed that the material should be published in full, and F. W. Armstrong helpfully suggested that the best way for future reference would be to divide the material into Technical Notes on related topics, each capable of standing alone. These have been reworked to stand separately, as follows:

• 1) Fuel consumption formulae and the general range equation

• 2) The Stream Force Theorem and applications to propulsion

• 3) Non-isentropic duct flow and the general wake traverse

• 4) Propulsion streamtubes in supersonic flow and the first supercritical intake cowl

• 5) Rotary jet thrust augmenters

• (a) fallacy of Foa’s theory and correction

• (b) the jet fan augmenter.