View source for Avro 707

{{Short description|British experimental aircraft (1949–1967)}}
{{distinguish|Boeing 707}}
{{Use dmy dates|date=May 2017}}
{{Use British English|date=May 2017}}
{{Infobox aircraft
|name= Avro 707
|image= File:Avro 707B VX790 in flight c1951.jpg
|caption= Avro 707B ''VX790'' in flight, 1951. [[NACA]] air intake.
|type= [[Experimental aircraft]]
|manufacturer= [[Avro]]
|designer=
|first_flight= 4 September 1949
|introduction=
|retired= 1967
|status= 3 aircraft survive in museums
|primary_user= Avro
|more_users= [[Royal Aircraft Establishment]] <br />Australian Aeronautical Research Council
|produced= <!--years in production, e.g. 1970-1999, if still in active use but no longer built-->
|number_built= 5
|unit cost=
|variants=
|developed_into= [[Avro Vulcan]]
}}
The '''Avro 707''' (also known as '''Type 707''') is an experimental aircraft designed and produced by the British aircraft manufacturer [[Avro]].<ref>Force V: The history of Britain's airborne deterrent, by Andrew Brookes. Jane's Publishing Co Ltd; First Edition 1 Jan. 1982, {{ISBN|0710602383}}, p.43, 44, 47, 48.</ref>

It was developed to test the [[tailless aircraft|tailless]] thick [[delta wing]] configuration chosen for the Avro 698 jet [[bomber]], later named the [[Avro Vulcan|Vulcan]]. In particular, the low-speed characteristics of such aircraft were not well known at the time. Aerodynamically, it was a one-third scale version of the Vulcan. The second prototype, ''VX790'', was built to the ''707B'' configuration, featuring a longer nose, alternative cockpit canopy, a modified wing with (51°) sweep, and an elongated nose wheel leg for a greater angle of incidence during both landing and take offs. The twin-seat ''707C'', the final variant, which had been designed to perform delta wing orientation training with the [[Royal Air Force]]; however, no production aircraft would ultimately be produced. The handful of 707s that were produced were largely used for flight testing purposes.

On 4 September 1949, the first Avro 707 performed its [[maiden flight]] from RAF Boscombe Down; low-speed testing began shortly thereafter. Higher speed testing commenced in late 1953 using the third aircraft, the first ''707A''. After development of the Vulcan had been completed, the four surviving 707s continued to be flown as general research aircraft. The prototype 707C was involved in various research programmes, the majority of which were unconnected to the Vulcan. Numerous tests involving the type were conducted by both the [[Royal Aircraft Establishment]] (R.A.E) and the Aeronautical Research Laboratories in Australia. During the early 1950s, the Avro 707 performed several public appearances at the [[Farnborough Airshow]]s. The last flying Avro 707 was grounded during 1967; three aircraft have been preserved and placed on static display in museums.

==Design and development==
[[File:Avro 707A WD280 in flight c1951.jpg|thumb|An Avro 707A in flight, 1951.]]
The Avro 707 originated as a "proof-of-concept" [[delta wing]] aircraft that was principally the work of [[Stuart Davies (engineer)|Stuart D. Davies]], Avro's chief designer. It was a relatively compact aircraft that initially incorporated a wing with about 50° sweep, without a horizontal tail on a fin with [[trailing edge]] sweep. The trailing edge of this wing carried two pairs of control surfaces: inboard [[elevator (aeronautics)|elevators]] and outboard [[aileron]]s. These flight surfaces worked in conjunction with a conventional [[rudder]].<ref name = "jackson 422"/> Retractable [[air brake (aeronautics)|airbrakes]] were also provided above and below the wings.<ref>Buttler 2007, p. 54.</ref> The aircraft featured all-metal stressed-skin construction.<ref name = "jackson 422">Jackson 1965, p. 422.</ref>

The prototypes were ordered by the [[Ministry of Supply]] to fulfil [[List of Air Ministry specifications#1940–1949|Specification E.15/48]], which called for a low-speed research aircraft that would be a one-third scale version of [[Avro Vulcan|Avro's B.35/46]] design for a [[strategic bomber]]. Production of this aircraft was accelerated by using several components from other aircraft, such as the canopy of the first prototype being taken from a [[Gloster Meteor]].{{#tag:ref|"Off-the-shelf" parts included an [[Avro Athena]] main undercarriage leg and Gloster Meteor nose leg.<ref name="Harlin and Jenks p. 174">Harlin and Jenks 1973, p. 174.</ref><ref name = "jackson 422"/>|group=N}}<ref>Buttler 2007, p. 52.</ref><ref name = "bae official">{{cite web |url = https://www.baesystems.com/en-uk/heritage/avro-707 |title = Avro 707 |publisher = [[BAE Systems]] |access-date = 31 December 2023}}</ref> The Avro 707 programme provided valuable insights into the Vulcan's flight characteristics, most of the information coming from the second and third prototypes which flew before the Vulcan. A half-scale aircraft, the ''Avro 710'', was cancelled when it became clear that it would be less time-consuming to develop a high-speed variant of the Avro 707 instead.<ref>Laming 2002, p. 27.</ref><ref name="blackman21">Blackman 2007, p. 21.</ref>

All Avro 707s were powered by a single [[Rolls-Royce Derwent]] centrifugal turbojet engine. The air intake on the first prototype and later 707B was located on the upper rear fuselage.<ref>Winchester 2005, p. 123.</ref> Some aircraft were outfitted with [[ejection seat]]s.<ref>Laming 2002, p. 29.</ref> In total, five Avro 707s were completed.<ref>Buttler 2007, pp. 54–55.</ref>{{#tag:ref|The last three Avro 707s flew after the Vulcan's first flight on 30 August 1952.|group=N}}

==Operational history==
[[File:Avro 707 Farnborough 1951.jpg|thumb|The Avro 707B at [[Farnborough Airshow|Farnborough]], in 1951.]]
On 4 September 1949, the first Avro ''707'', ''VX784'', performed its [[maiden flight]] from [[MOD Boscombe Down|RAF Boscombe Down]], Squadron Leader Samuel Eric Esler, DFC, AE, was at the controls.<ref name = "jackson 422"/> Two days later, it was statically displayed at the [[Farnborough Airshow]]. However, testing with the first prototype was cut shortly when, on 30 September 1949, it crashed near [[Blackbushe Airport|Blackbushe]] during a test flight, killing Esler.<ref>Hewitt 2003, p. 168.</ref><ref name = "jackson 422"/> The loss of the first prototype led to the construction of the second prototype being temporarily halted while the design was re-examined, leading to several refinements being implemented.<ref name = "dunsfold history">{{cite web |url = https://dunsfoldairfield.org/avro-707b/ |title = Avro 707B |publisher = Dunsfold Airfield History Society |access-date = 31 December 2023}}</ref>

The next prototype, ''VX790'', renamed the ''707B'', had a longer nose, different cockpit canopy, a wing of different (51°) sweep and a longer nose wheel leg to provide the high angle of incidence required by deltas for landing and take off. The Avro 707B was given the same dorsal engine intake as the first prototype, although this was later modified to a [[NACA duct|NACA]] design. It first flew on 6 September 1950; the aircraft quickly proved to be relatively docile in flight.<ref name = "jackson 422"/><ref name = "dunsfold history"/> Both the 707 and 707B were largely flown to test low speed characteristics.<ref name = "jackson 422"/>

The third aircraft, designated ''707A'', ''WD280'' was built for higher speed testing.<ref name = "jackson 423"/> Experience with the dorsal intake of the earlier 707 and 707B had shown that as speed increased, the cockpit induced turbulence which interrupted the intake airflow, thus the intakes were repositioned to the [[wing root]]s.<ref name="Harlin and Jenks p. 176">Harlin and Jenks 1973, p. 176.</ref> It was not designed for [[supersonic]] flight as it was felt this would necessitate both power-operated flight controls and far greater engine power.<ref name = "jackson 423"/> When the Vulcan appeared, it looked very much like an enlarged 707A. Later, this 707A was used to test the compound leading edge sweep subsequently used on all Vulcans. Although the first Vulcan prototype was already flying, a second 707A ''WZ736'' was produced to speed the development programme. It made its maiden fight on 20 February 1953.<ref name = "jackson 423"/>

The final variant was the two-seat ''707C''; originally four examples were ordered by the RAF with the intention of conducting orientation training for flying aircraft with delta wing configurations using the type.<ref name = "jackson 423"/> The 707C was provisioned with a wider cockpit to accommodate a "side-by-side" seating arrangement and dual flight controls. However, the production order was cancelled; accordingly, only the sole prototype, ''WZ744'', was built.<ref name="Harlin and Jenks p. 176"/> The 707C had its maiden flight on 1 July 1953 and was ultimately employed in other research that did not involve Vulcan development.<ref name="Buttler p. 55">Buttler 2007, p. 55.</ref><ref name="blackman21"/>

[[File:Avro Vulcan VX770 VX777 FAR 13.09.53 edited-2.jpg|thumb|right|Two Avro 707As, a 707B and a 707C with both Vulcan prototypes at the SBAC [[Farnborough Air Show]] in September 1953]]

Even after the Vulcan development phase was over, the four surviving 707s, in individual bright blue, red, orange and silver (natural metal) colour schemes, continued in use as research aircraft.<ref name="Buttler p. 55"/><ref name="blackman21"/> After the compound sweep investigation,<ref name = "jackson 423">Jackson 1965, p. 423.</ref> and a period with the [[Royal Aircraft Establishment]] (R.A.E) carrying out handling trials with powered controls,<ref name="Cooper p.108">Cooper 2006, p. 108.</ref> the first 707A went to the Aeronautical Research Laboratories in Australia for low-speed delta wing airflow measurements. The second 707A was also at the R.A.E from June 1953 for aerodynamic and later, automatic control investigations.

During September 1952, the Avro 707B joined the R.A.E.,<ref name="Cooper p.108"/> becoming one of the aircraft used by the [[Empire Test Pilots School]] from January to September 1956,<ref>Cooper 2006, p. 85.</ref> when it was damaged on landing, and broken up at R.A.E. Bedford.<ref name="Harlin and Jenks p. 176"/><ref name = "dunsfold history"/> The two-seat 707C joined the R.A.E. in January 1956; perhaps its most substantial research contribution was to the development of [[Aircraft flight control systems#Fly-by-wire control systems|fly-by-wire control]] systems, one of the first of their kind, and fitted with a side stick controller. This aircraft was flying with the R.A.E. until September 1966 when it achieved its full airframe time.<ref name="ElectricHunter">Wilson, Michael, Technical editor. [http://www.flightglobal.com/pdfarchive/view/1973/1973%20-%201822.html "Avionics: RAE Electric Hunter."] ''Flight International'', 28 June 1973. Retrieved: 3 July 2011.</ref>

The Avro 707s made numerous public appearances at the [[Farnborough Airshow]] throughout the 1950s. During 1952, the first prototype Vulcan flew with the 707s A and B and in 1953, the four surviving Avro 707s flew alongside the first two Avro 698 Vulcan prototypes.

==Surviving aircraft==
[[File:Avro 707A WZ736 MSIM 10.08.85R edited-2.jpg|thumb|right|The second Avro 707A ''WZ736'' displayed next to an [[Avro Shackleton]] at the [[Museum of Science and Industry (Manchester)|Museum of Science and Industry in Manchester]] in 1985]]

No Avro 707s are presently airworthy. Both examples of the 707A variant survive. One, ''WZ736'', was preserved in Great Britain at the [[Museum of Science and Industry in Manchester]], but has been transferred to the [[Boscombe Down Aviation Collection]] at Old Sarum, while the other, ''WD280'', is preserved in Australia at the [[RAAF Museum]] at [[Point Cook, Victoria]]. Also in Great Britain is ''WZ744'', the single 707C prototype, which was displayed at the [[Royal Air Force Museum Midlands]], Cosford near [[Wolverhampton]] and is currently stored out of public view with its space in the museum's Test Flight hall taken by the [[British Aerospace EAP]].<ref>Jackson 1965, pp. 422–445.</ref>

==Operators==
;{{AUS}}
* [[Royal Australian Air Force]]
* [[Aeronautical Research Laboratories]]
;{{UK}}
* Aeroplane and Armament Experimental Establishment
* [[Royal Aircraft Establishment]]

==Specifications (707C)==

{{Aircraft specs
|ref= ''Avro Aircraft since 1908''<ref name=Jackson>{{cite book |last1 = Jackson |first1 = A.J. |title = Avro Aircraft since 1908 |url=https://archive.org/details/avroaircraftsinc1908jack_906 |url-access = limited |date = 1965 |publisher = Putnam |location = London |pages = [https://archive.org/details/avroaircraftsinc1908jack_906/page/n158 319]-333}}</ref>
|prime units?= imp
<!--
        General characteristics
-->
|crew= 2
|length ft= 42
|length in= 4
|length note=
|span ft= 34
|span in= 2
|span note=
|height ft= 11
|height in= 7
|height note=
|wing area sqft= 420
|wing area note={{citation needed|date=April 2020}}
|aspect ratio=<!-- sailplanes -->
|airfoil= [[NACA airfoil|NACA 0010 mod]]<ref name="Selig">{{cite web |last1 = Lednicer |first1 = David |title = The Incomplete Guide to Airfoil Usage |url = https://m-selig.ae.illinois.edu/ads/aircraft.html |website = m-selig.ae.illinois.edu |access-date = 16 April 2019}}</ref>
|empty weight lb=
|empty weight note=
|gross weight lb= 10,000
|gross weight note=
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number= 1
|eng1 name= [[Rolls-Royce Derwent|Rolls-Royce Derwent 8]]
|eng1 type= [[centrifugal-flow turbojet]] engine
|eng1 lbf= 3,600
|eng1 note={{citation needed|date=April 2020}}
<!--
        Performance
-->
|max speed mph= 464
|max speed note={{citation needed|date=April 2020}}
|max speed mach=<!-- supersonic aircraft -->
|cruise speed mph=
|cruise speed note=
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|range miles=
|range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|wing loading lb/sqft= 22.6
|wing loading note={{citation needed|date=April 2020}}
|fuel consumption lb/mi=
|thrust/weight= 0.38{{citation needed|date=April 2020}}

|more performance=<!--<br />
* '''Take-off run:''' {{cvt||ft|0}}
* '''Take-off distance to {{cvt|50|ft|0}}:''' {{cvt||ft|0}}
* '''Landing run:''' {{cvt||ft|0}}
* '''Landing distance from {{cvt|50|ft|0}}:''' {{cvt||ft|0}}-->

|avionics=
}}

==See also==
{{Portal|UK|Aviation}}
{{aircontent
|related=
* [[Avro Vulcan]]
|similar aircraft=
* [[Boulton Paul P.111]]
* [[Bristol 188]]
* [[Convair XF-92]]
* [[Dassault Mirage|Dassault Mirage I]]
* [[Dassault MD.550 Mystere-Delta]]
* [[English Electric Lightning|English Electric P1A]]
* [[Fairey Delta 1]]
* [[FMA I.Ae. 37]]
* [[Handley Page HP.88]]
* [[Saab 210]]
}}

==References==
===Notes===
{{Reflist|group=N}}

===Citations===
{{Reflist}}

===Bibliography===
* {{cite book |last = Blackman |first = Tony |title = Vulcan Test Pilot: My Experiences in the Cockpit of a Cold War Icon |location = London, UK |publisher = Grub Street |date = 2007 |ISBN = 978-1-904943-88-4}}
* {{cite magazine |last = Buttler |first = Tony |title = Avro Type 698 Vulcan (Database) |magazine = Aeroplane |volume = 35 |number = 4 |date = April 2007}}
* {{cite book |last1 = Buttler |first1 = Tony |first2 = Jean-Louis |last2 = Delezenne |title = X-Planes of Europe: Secret Research Aircraft from the Golden Age 1946-1974 |location = Manchester, UK |publisher = Hikoki Publications |date = 2012 |ISBN = 978-1-902-10921-3}}
* {{cite book |last = Cooper |first = Peter J. |title = Farnborough: 100 years of British Aviation |location = Hinkley, UK |publisher = Midland Books |date = 2006 |ISBN = 1-85780-239-X}}
* {{cite book |last1 = Harlin |first1 = E.A. |first2 = G.A. |last2 = Jenks |title = Avro: An Aircraft Album |location = Shepperton, Middlesex, UK |publisher = Ian Allan |date = 1973 |ISBN = 978-0-7110-0342-2}}
* {{cite book |last = Hewitt |first = John C. |title = Ireland's Aviator Heroes of World War II |publisher = Mercier Press Ltd. |date = 2003 |isbn = 1-78117-388-5}}
* {{cite book |last = Jackson |first = A.J. |title = Avro Aircraft since 1908 |location = London, UK |publisher = Putnam & Co. |date = 1965}}
* {{cite book |last = Jackson |first = Robert |title = Combat Aircraft Prototypes since 1945 |location = New York, US |publisher = Arco/Prentice Hall Press |date = 1986 |ISBN = 0-671-61953-5}}
* {{cite book |last = Laming |first = Time |author-link = Tim McLelland |title = The Vulcan Story: 1952–2002 |location = Enderby, Leicester, UK |publisher = Silverdale Books |date = 2002 |ISBN = 1-85605-701-1}}
* {{cite book |last = Winchester |first = Jim. |chapter = Avro 707 (1949) |title = X-Planes and Prototypes |location = London, UK |publisher = Amber Books Ltd. |date = 2005 |ISBN = 1-904687-40-7}}

==External links==
{{Commons}}
* [http://www.aeroflight.co.uk/types/uk/avro/707/707.htm Aeroflight]

{{Avro aircraft}}
{{British military aircraft since World War II}}
{{Authority control}}

[[Category:Avro aircraft|707]]
[[Category:1940s British experimental aircraft]]
[[Category:Tailless delta-wing aircraft]]
[[Category:Single-engined jet aircraft]]
[[Category:Aircraft first flown in 1949]]
[[Category:Aircraft with retractable tricycle landing gear]]
[[Category:Mid-wing aircraft]]