Editing Avro Vulcan (section)

====First prototype VX770 and name====
[[File:Comparison of Vulcan Planforms.jpg|thumb|upright|Comparison of Vulcan wing designs]]
More influential than the Avro 707 in the 698's design was the wind-tunnel testing performed at RAE [[Farnborough Airport|Farnborough]]. This necessitated a wing redesign incorporating a cranked and drooped leading edge and [[vortex generators]] to avoid the onset of [[Compressibility#Aeronautical dynamics|compressibility]] drag, which would have restricted the maximum speed.<ref>Laming 2002, p. 43.</ref> This wing modification resulted in the "phase 2" wing which was first investigated on Avro 707A WD480. This modification was too late to be incorporated on the two prototype 698s and the first three B.1 aircraft before their first flights. (The B.1s were quickly retrofitted).

Painted gloss white, the 698 prototype VX770, with its pure delta wing, flew for the first time on 30 August 1952 piloted by [[Roland Falk|Roly Falk]] flying solo.<ref>Darling 2007, p. 13</ref> VX770, fitted with only the first pilot's ejection seat and a conventional control wheel, was powered by four [[Rolls-Royce Avon|Rolls-Royce RA.3 Avon]] engines of {{convert|6500|lbf|kN|abbr=on}} thrust, its intended [[Bristol Olympus]] engines not being available. The prototype had fuselage fuel tanks but no wing tanks, so temporary additional tankage was carried in the bomb bay.<ref>Blackman 2007, pp. 38, 40.</ref> VX770 made an appearance at the 1952 [[Society of British Aerospace Companies|Society of British Aircraft Constructors']] (SBAC) Farnborough Air Show the next month when Falk demonstrated an almost vertical bank.<ref name="Empire">Hamilton-Paterson 2010, pp. 18–19.</ref>

After its Farnborough appearance, the future name of the Avro 698 was a subject of speculation. Avro had strongly recommended the name ''Ottawa'',{{refn|RAF bombers had been traditionally named after inland towns in the British Commonwealth or towns associated with industry.<ref name='white44'>Wansbrough-White 1995, p. 44.</ref>|group=N}} in honour of the company's connection with [[Avro Canada]].<ref name = 'but 31'/><ref name='white44'/> The weekly magazine ''[[Flight International|Flight]]'' suggested ''Albion'' after rejecting ''Avenger'', ''Apollo'', and ''Assegai''. The chief of the air staff preferred a V-class of bombers, and the Air Council announced the following month that the 698 would be called ''Vulcan'' after the [[Vulcan (mythology)|Roman god of fire and destruction]].<ref name='brookes8'>Brookes and Davey 2009, p. 8.</ref>

In January 1953, VX770 was grounded for the installation of wing fuel tanks, [[Armstrong Siddeley Sapphire|Armstrong Siddeley ASSa.6 Sapphire]] engines of {{convert|7500|lbf|kN|abbr=on}} thrust and other systems; it flew again in July 1953.<ref>Blackman 2007, p. 41.</ref>

From 1957, VX770 was used as the flying testbed for the [[Rolls-Royce Conway]] [[turbofan|by-pass]] engine. It crashed at [[1958 Syerston Avro Vulcan crash|a flying display]] at [[RAF Syerston]] in September 1958.<ref name="auto">Darling 2007, p. 15.</ref>