Editing Frank Whittle (section)

===Rover===
Meanwhile, work continued with the W.U., which eventually went through nine rebuilds in an attempt to solve the combustion problems that had dominated the testing. On 9 October the W.U. ran once again, this time equipped with Lubbock or "Shell" atomising-burner combustion chambers.<ref>Developed by Isaac Lubbock of the Shell combustion laboratories in Fulham.{{harvnb|Nahum|2004|pp=80–81}}</ref> Combustion problems ceased to be an obstacle to development of the engine although intensive development was started on all features of the new combustion chambers.<ref>"The early history of the Whittle jet propulsion Gas Turbine" Air Commodore F. Whittle, James Clayton Memorial Lecture 1945, Institution of Mechanical Engineers, pp. 428–430</ref>

By this point it was clear that Gloster's first airframe would be ready long before Rover could deliver an engine. Unwilling to wait, Whittle cobbled together an engine from spare parts, creating the W.1X ("X" standing for "experimental") which ran for the first time on 14 December 1940.{{sfn|Nahum|2004|p=89}} Shortly afterwards an application for a US patent was made by Power Jets for an "Aircraft propulsion system and power unit"<ref>{{cite web|url=https://patents.google.com/patent/US2404334A/en|title=Aircraft propulsion system and power unit|access-date=20 April 2020}}</ref>

The W.1X engine powered the E.28/39 for taxi testing on 7 April 1941 at Brockworth near the factory in Gloucester, where it took to the air for two or three short hops of several hundred yards at about six feet from the ground.<ref name ="Whittle quantal DVD"/>

The definitive W.1 of 850&nbsp;[[lbf]] (3.8&nbsp;[[kilonewton|kN]]) thrust ran on 12 April 1941, and on 15 May the W.1-powered E.28/39 took off from Cranwell at 7:40&nbsp;pm, flying for 17&nbsp;minutes and reaching a maximum speed of around 340&nbsp;mph (545&nbsp;km/h). At the end of the flight, Pat Johnson, who had encouraged Whittle for so long said to him, "Frank, it flies."  Whittle replied, "Well, that's what it was bloody well designed to do, wasn't it?"<ref name=tele/><ref>[https://web.archive.org/web/20040508125109/http://businessweek.com/magazine/content/04_18/b3881044_mz072.htm Frank Whittle: A Daredevil Who Built Jets], ''Bloomberg BusinessWeek''</ref>

Within days the aircraft was reaching 370&nbsp;mph (600&nbsp;km/h) at 25,000&nbsp;feet (7,600&nbsp;m), exceeding the performance of the contemporary [[Supermarine Spitfire]] fighters. Success of the design was now evident, and in 1941, [[Rolls-Royce Holdings|Rolls-Royce]], [[Hawker Siddeley]], the [[Bristol Aeroplane Company]], and [[de Havilland]] became interested in gas turbine aircraft propulsion.{{sfn|Golley|1987|pp=171, 178}} Under [[Roxbee Cox, Baron Kings Norton|Harold Roxbee Cox]], the Gas Turbine Collaboration Committee was created to give a forum for all the companies for exchange of information.<ref>Nahum 2004 p 66-67</ref>

The stress on Whittle was expressed in a 27 May 1941 letter to [[Henry Tizard]]:
{{cquote|The responsibility that rests on my shoulders is very heavy indeed. We are faced with two alternatives – either we place a powerful weapon in the hands of the Royal Air Force or, if we fail to get our results in time, we may have falsely raised hopes and caused action to be taken which may deprive the Royal Air Force of hundreds of aeroplanes that it badly needs.{{sfn|Nahum|2004|p=57}}{{sfn|Golley|1987|p=173}}}}

[[File:Whittle Jet Engine W2-700.JPG|thumb|left|The [[Power Jets W.2|W2/700]] engine, or W.2B/23 as it was known to the Air Ministry. It was the first British production jet engine, powering early models of the [[Gloster Meteor]].]]
In mid-1941, relations between Power Jets and Rover had continued to deteriorate.  Rover had established a version of Power Jet's set-up at Waterloo Mill, associated with their [[Barnoldswick]] factory, near [[Clitheroe]]. Rover was working on an alternative to Whittle's "reverse-flow" combustion chambers, by developing a "straight-through" combustion chamber and turbine wheel.  Rover referred to the engine as the B.26, sanctioned by the Directorate of Engine Development, but kept secret until April 1942, from Power Jets, the Controller of Research and Development, and the Director of Scientific Research.{{sfn|Golley|1987|pp=174, 189–191}}