Research into delta-wing aircraft had also been conducted by the Royal Aircraft Establishment (RAE) at Farnborough, and the combined results of this programme and that of the Avro team brought about a number of changes in the design. The wing became thinner, with the engines buried inside with their intakes built into the wing roots, and wingtip fins were deleted in favour of a large central fin, the whole aeroplane taking on the appearance of the Vulcan which is so well known today.
The order covering two Avro 698 prototypes was received in January 1948, and work commenced immediately. To investigate the practically unknown characteristics of the delta design it was decided that a series of one-third scale research aircraft would be built, and these were designated the Avro 707s, with the design work commencing in May of that year.
The first Avro 707 was a fairly simple aeroplane, with an unusual engine air intake built into the top of the fuselage behind the cockpit. To speed construction, the aircraft utilised the cockpit and nose-wheel leg of a Gloster Meteor, and the main undercarriage of an Avro Athena. This aircraft was flown for the first time on September 4th 1949 by Avro test pilot S.E. ‘Red’ Esler, who two days later took it to Farnborough where it appeared in the famous Air Show. Unfortunately it crashed near Blackbushe on September 30th, and Esler was killed.
Avro 707s of varying designs were flown, and had contributed valuable research to the Avro 698 programme before the bomber prototype, VX770, took to the air on August 30th 1952, in the capable hands of the Company’s chief test pilot R.J. ‘Roly’ Falk. This was flown in time to appear at the 1952 Farnborough Air Show, where the aircraft put on a show-stopping performance, before settling down to handling trials at Boscombe Down.
The chosen powerplant, the Bristol Olympus, was not yet ready when the Avro 698 was approaching completion, so the prototype was powered by four Rolls-Royce Avons at the time of its first flight, each generating 6,500lbs thrust. In order to extend the aircraft’s flight envelope VX770 was later powered by Armstrong Siddeley Sapphires (with 7,500lbs thrust), before the second prototype VX777 made its initial flight on September 3rd 1953, with four Bristol Olympus 100 engines (developing 9,750lbs thrust).
The Birth of the Vulcan
In January 1953, the name Vulcan had been chosen for the aircraft, to complete the famous RAF V-Bomber trio of the Vickers Valiant, Handley Page Victor and the Avro Vulcan. The Victor had been one of the Vulcan’s competitors for the B.35/46 specification, and the Valiant was an interim V-Bomber designed to a slightly less demanding (B.9/48) specification.
The flight of the second prototype Vulcan had come just in time for this aircraft to take part in the 1953 S.B.A.C. (Society of British Aerospace Companies) display at Farnborough, and the crowds were treated to the never-to-be forgotten sight of two Vulcans, flanked by four Avro 707s, in a memorable fly past.