WHITTLE FRANK: (1907-1996)

WHITTLE FRANK: (1907-1996) English Air Commodore, inventor and engineer, credited with the invention of the turbojet engine which culminated in the first British jet-engined aircraft, the Gloster E.28/39, flying on 15th May 1941. An historically important document prepared by Whittle, unsigned, although with a few corrections in his hand, titled Report on First Tests of an Experimental Gas Turbine by Squadron-Leader F. Whittle, R.A.F., marked 'Confidential', and one of five copies, being the first confidential report delivered to the Air Ministry by Power Jets Ltd. 'in fulfilment of Item No.1 of Research Contract', thirty-six pages, folio, with three fold-out appendices at the conclusion, n.p., 31st March 1938. The typescript (carbon copy) report describes, in detail, the initial tests of a constant pressure gas turbine intended for aircraft propulsion by jet reaction and the experiments carried out under Whittle's supervision between April and August 1937, the introduction stating, in part, 'At the time when the development of the propulsion unit was under consideration, there was no intention of making a complete engine at once, partly because definite ideas as to its final form were rather nebulous, but mainly because a sufficient knowledge of the performance of the different components for design purposes was lacking. It was therefore intended to adopt a step by step process, commencing with tests on a high speed single stage centrifugal compressor. It was decided that this should be of the size to be used in the engine…..because it was believed that to make tests on a smaller scale would lead to misleading results' and the document continuing with reports on Design and Construction (including the strength of the materials when exposed to high temperature, the rotor assembly, the 'very unorthodox feature' of the turbine nozzle, etc.), the results of Preliminary Combustion Tests ('These tests at least proved that the required combustion rates could be obtained, though for various reasons, they did not provide sufficient information for the avoidance of combustion trouble in the engine itself……Ignition of the atomising sprays by high tension spark proved to be easy at moderate air speeds, but as the electrodes were damaged early in the tests, ignition was mainly achieved by the insertion of burning oily waste through a flap……The quality of combustion was judged by the appearance of the flame, the presence or otherwise of visible smoke or fuel vapour, and the smell and the effect on the eyes of the exhaust'), Tests with Atomising Sprays, Plain Sprays ('The flame was very intense, and for the speed, the combustion was the best that had been achieved up to that time. It appeared, however, that the system was very sensitive to jet alignment, and this was largely true of all similar systems tried'), Testing Arrangements ('For test purposes, the unit was mounted on a four wheeled trailer. This trailer also carried the starter motor, instrument board and controls, making the set self-contained with the exception of the fuel and water supply….For starting, it was considered to be necessary to spin the rotor up to about 3000 r.p.m. after which it was expected to be capable of accelerating under its own power…..The instruments and their connections were considerably modified in the course of the tests. Pressure gauges were connected to six points on the compressor casing…..The tachometer was mounted on the top of the gear case in such a position that it could be seen through a hole in the instrument board'), further providing a description of the test runs of the unit, subdivided into four categories, in part, 'For the test runs, the starting procedure was as follows:- The rotor was motored over at about 1000 r.p.m. and the pilot jet ignited by the hand magneto. The speed was then raised to 2000 r.p.m., at which speed the main jet was opened and the unit accelerated under its own power…..No trouble was ever experienced in starting other than occasional trouble with the initial ignition through cracked electrodes, and in fact the very first attempt to start was successful……Five runs were made with this system, the maximum speed reached being 8,500 r.p.m. beyond which the unit would not accelerate on further opening of the control…..Of these five runs, uncontrolled acceleration occurred in one case, otherwise it was found possible to hold the unit at a steady speed with the control', also giving a discussion of the results and Whittle's conclusions. A document of exceptional content and major significance in Whittle's development of the jet engine, the historical importance of which cannot be overstated, the jet engine being one of the most important of the 20th century, affecting the life of almost very human being. Loosely bound in the original plain paper wrappers, with a typed title to the cover, and all of the pages with two files holes to the left edges. Some very light, minor overall age wear and some light staining and a few minor tears to the edges of the paper covers, about VG The invention of the turbo-jet engine, and the determined effort to design and develop it to replace piston engines in the air, was one of the most important technical achievements of the 20th century. That one man accomplished this, working with a small but dedicated team of engineers and craftsman in the middle of a war, and in the face of many doubters, was a truly monumental achievement. The jet engine conceived by Frank Whittle, a young RAF officer who had the necessary intellect, vision, and dedication to fulfil his dream of flying higher and faster, made the world a village, and introduced world-wide travel to ordinary people everywhere. Provenance: Acquired by our vendor from John Wilson (Autographs) Ltd., Witney, Oxfordshire, on 24th June 1980. In his catalogue description Wilson notes that of the five copies which were prepared 'two, perhaps three, are believed to have been destroyed'. The document has not been offered for sale or appeared at auction at any time since, until now.