Development Fairey Delta 2

1 development

1.1 background
1.2 flight testing
1.3 breaking world airspeed record
1.4 proposed derivatives
1.5 bac 221

development
background

during late 1940s, fairey aviation, british aircraft manufacturer, had become interested in delta wing technology , proceeded submit multiple submissions based on delta wing concept ministry of supply. ministry, being interested in these proposals, issued orders models test envisioned delta wing, first of being built in 1947; testing performed royal aircraft establishment (rae). program succeeded multiple times, including investigation potential vtol operations, leading further flight tests of delta wing models conducted in cardigan bay, wales , woomera, australia. in 1947, air ministry specification e.10/47 issued full-scale piloted delta wing aircraft, resulting in fairey delta 1, conducted maiden flight @ raf boscombe down on 12 march 1951.

meanwhile, throughout , mid 1950s, royal air force (raf) had developed intense desire advance performance of aircraft; in particular, service sought new fighter aircraft capable of routinely flying @ high speeds , high altitudes long term replacement existing inventory of 700 first-generation jet fighters. @ time, there perception britain trailing behind in supersonic aircraft design, , there pressure correct this. events such korean war , rapid advances in fields of supersonic aerodynamics, structures , aero engines british aircraft industry had effect of increasing demand , potential capabilities of new fighters. in addition developing improved versions of existing , emerging fighters such hawker hunter , gloster javelin, there appetite more promising entirely new aircraft.

following on delta 1, ministry of supply requested fairey conduct further model programme purpose of transonic investigations. however, fairey did not find proposal attractive, believing piloted aircraft mandatory if project produce worthwhile data. fairey commenced work on highly swept twin-engine aircraft; however, ministry lacked enthusiasm twin-engine configuration, largely due existing rival project underway produce twin-engine supersonic aircraft - become english electric lightning. in february 1949, suggested fairey examine prospects single-engine transonic aircraft alternative; end of year, company had produced new project, out of fairey delta 2 (fd2) directly originate. accordingly, ministry issued air ministry specification er.103 project, ordering pair of prototype aircraft produced.

the first delta 2 wg774 in original design format landing @ farnborough in 1956 during year s sbac show using droop snoot

at time, fairey known producing naval aircraft, such fairey swordfish biplane , fairey firefly monoplane; design team lacked experience high speed projects. remedy this, in october 1951, sir robert lickley of hawker aircraft promptly recruited fairey s new chief engineer , became major force behind programme. data had been obtained earlier model work proved have been highly valuable fairy delta 2 programme. development work on fd2 hindered 2 major factors, lack of available information on wing , intake design, , declaring of fairey gannet super-priority british government, had necessitated delays.

in september 1952, technical drawings of fairey delta 2 issued , development proper commenced. project s beginning, fairey designed parameters of fd2 intentionally exceed necessary achieving mach 1. in addition seeking high performance, design adopted general configuration , structure readily adapted future military requirements, potentially become fighter aircraft. in total, pair of flight-capable aircraft produced: serial numbers wg774 , wg777. wg777, second manufactured, similar wg774 apart underwing flap system have been eliminated, there few differences in terms of equipment , instrumentation. in addition 2 flying aircraft, single static test airframe completed.

flight testing

on 6 october 1954, wg774, first fd2 completed, conducted maiden flight, flown fairey test pilot peter twiss. according aviation author derek wood, delta 2 proved exceptional aeroplane outset . on 17 november 1954, wg774 suffered engine failure on 14th flight when internal pressure build-up collapsed fuselage collector tank, closing off fuel supply engine, while heading away airfield @ 30,000 ft (9,100 m), 30 mi (50 km) after take-off raf boscombe down. twiss managed glide dead-stick landing @ high speed on airfield. nose gear had deployed, , aircraft sustained damage sidelined 8 months. twiss, shaken experience otherwise uninjured, received queen s commendation valuable service in air. 1 result of crash temporary halt on test programme, did not resume until august 1955.

during flight tests, repeated supersonic test runs on southern britain conducted; result of these flights, number of claims damages against supersonic booms received. tests of delta 2 s low-level supersonic flight capability disrupted due perceived heightened risk posed supersonic booms being produced during lower altitude flight; such, ministry of supply refused allow testing performed on uk. result of refusal, fairey chose transport delta 2 first france , later norway tests performed. french government required tests insured against damage claims; demand had proved impractical british-based insurance company due unrealistic prices; however, french company insured them £40. no claims ever received in either france or norway.

wg774 original polished-metal finish. later received yellow go faster stripes, followed purple , yellow scheme, before conversion bac 221

on 15 february 1956, wg777, second delta 2, performed maiden flight raf boscombe down; piloted twiss, aircraft proceeded reach transonic speeds during first flight. following final contractor check flight on 14 april 1956, wg777 formally accepted, upon assigned rae s high-speed research programme, conducting measurement, stability , handling research. in september 1956, both aircraft performed flight displays @ farnborough airshow in hampshire. delta 2 typically used conduct multitude of tests including aerodynamics characteristics, handling, , stability performance.

testing of delta 2 carried out in france time, in part due fairey s relations dassault aviation of france , french air force. in october , november 1956, total of 47 low level supersonic test flights conducted cazaux air base, bordeaux, france; detachment of dassault engineers closely observed these trials, learning great deal delta wing aircraft fd2. dassault went on produce md.550 mystère-delta design, wood notes have bore striking resemblance fd2; md.550 design proceed manufactured successful dassault mirage iii fighter. wood credits delta 2 having served confirm dassault s theories , supporting designing , development of mirage iii.

once manufacturer s testing completed, both aircraft formally handed on rae. in addition providing institution useful information on characteristics of 60°-swept delta wing, 1958 onwards, fd2 aircraft participated in various research projects , flying trials, including investigation performance of ejection-type propulsive nozzles. substantial rebuilding of aircraft participate in further research first mooted in same year well. in original configuration, delta 2 performed flight tests, interspersed periods of storage, until mid-1966.

breaking world airspeed record

during august 1955, delta 2 transitioned between subsonic , supersonic flight without use of reheat. according wood, many members of development team recognised fd2 possessed huge speed potential, beyond other british-built aircraft in existence of time. during flight testing, twiss came realise delta 2 capable of speeds above 1,000 miles per hour , proposed flown on aim of breaking current air speed record, had been held since 1955 north american f-100 super sabre. however, fairey found ministry of supply unsupportive; organisation having adopted prevailing belief being manned military aircraft replaced guided missiles; firm had great difficulty in obtaining permission attempt. twiss stated situation curiously inverted expectations, having expected government agencies have been enthusiastically pressing record-breaking flight means bolster national prestige.

according wood, fairey confronted combination of scepticism , apathy majesty s civil service, extent appeared government opposing endeavor. ministry of supply sought avoid association speed record bid while rolls-royce, fd2 s engine manufacturer, dismissed attempt, claiming air intakes unsuitable speeds around mach 1.5, , avon engine disintegrate @ such speeds, despite absence of practical data support assertion. in spite of opposition, fairey sought continue, , given permission proceed. ministry provided no financial support, having opted instead loan aircraft fairey , charge firm use of rae assets. fairey had finance own insurance. regardless, fairey chose continue record attempt.

the first fairey delta 2 (s/n wg774) in flight, circa 1956

in order reduce risk of competitor beating them it, preparations had carried out in short space of time , in great secrecy. development , deployment of equipment suitable accurate measurement of flight @ such speeds challenge in itself. purpose, variety of ground measurement cameras set @ chichester , @ rnas ford, various ground markers installed @ specified locations, , radar tracking rnas ford , raf sopley; flights gloster meteors , de havilland venoms calibration purposes conducted raf. operational demands on both pilot , ground crews severe , many runs attempted failed qualify on 1 technicality or another. on final day available, first run failed; second , last run day became chance left before attempt end.

on 10 march 1956, fairey delta 2 broke world air speed record, raising 1,132 mph (1,811 km/h) or mach 1.73. achievement exceeded prior recorded airspeed record 310 mph, or 37 per cent; never before had record ever been raised such vast margin. achievement had made fairey delta 2 first jet aircraft exceed 1,000 mph (1,600 km/h) in level flight. @ speed, when flying westward aircraft flies faster apparent motion of sun, making sun appear move backwards in sky; peter twiss became first man fly faster sun.

news of new airspeed record spread , made equally prompt impact upon international aeronautics industry, typical reactions being shock , near-disbelief. according wood, consequences included in-depth studies of fd2 airframe united states , major reshaping of military aircraft programs in france. fairey elated achievement, viewing practical endorsement of design, , fuelled firm s ambitions establish family of supersonic fighters on basis. record stood until 12 december 1957, @ point surpassed mcdonnell jf-101a voodoo of united states air force.

proposed derivatives

fairey produced number of proposals have involved further development of delta 2. first of these experimental aircraft, designated er.103/b, have paired wings of fd2 revised fuselage, had greater span , length. er.103/b have been powered either de havilland gyron or rolls-royce rb.122 , have accommodated underwing fuel tanks extended endurance. combat fighter model, er.103/c, proposed, upon wings have been scaled 50 per cent, no radical aerodynamic alterations made. combat equipment have been provisioned, including ferranti-built airborne interception radar 1495 , de havilland firestreak air-to-air missiles. fairey claimed er.103/c capable of attaining mach 2.26 @ altitude of 55,000 feet.

marcel dassault, founder of dassault aviation

according fairey s projections, er.103/b have been ready fly within eighteen months of having received order, while er.103/c reach same readiness within 30 months. in particular, fairey pursued operational requirement f.155, called two-seat fighter equipped radar , missiles suitable performance achieve altitude of 60,000 feet , mach 2 within 6 minutes of taking off; while company thought firm thought design able capable of meeting specified requirements, believed complete weapon system not developed until 1962. thus, fairey proposed simpler interim aircraft, if selected, available 1960 or potentially earlier.

in addition gyron engine of earlier proposals, proposed fighter equipped pair of de havilland spectre rocket engines mounted in fairings on rear fuselage. high-test peroxide (htp) fuel rocket engines stored in tanks held in underwing fairings , within wing s leading edge, separate turbojet engine s fuel storage. featured two-man crew, pilot , radar operator/navigation, seated in side-by-side configuration. fuselage area ruled while large rectangular variable air intakes adopted. specified, fighter tentatively armed wingtip-mounted de havilland red top air-to-air missiles. further design revisions saw single gyron engine being replaced pair of rb.122 engines instead , adoption of red dean missile, alongside refinements such intake improvements , increased internal fuel capacity. fairey stated aircraft suited interceptor duties @ various altitudes, strike , aerial reconnaissance missions mooted.

on 1 april 1957, fairey informed officials within ministry of supply proposals favourite meet operational requirement f.155. however, on 4 april 1957, duncan sandys, minister of defence, announced effective termination of fighter aircraft development raf, instantly removing f.155 requirement.

a final attempt made progress delta 2 derivative production came during late 1950s new german air force of west germany. running against competing american bid lockheed f-104g starfighter, fairey joined forces rolls-royce , dassault in collaborative effort produce delta wing aircraft capable of reaching mach 2 meet german demand fighter aircraft. proposal have seen dassault produce wings, fairey manufacture fuselage, , rolls-royce provide engine, intended rolls-royce spey engine reheat; belgium played role in programme. however, american lobby proved strong, in part due subsequently uncovered lockheed bribery scandals had influenced german decision makers, , f-104g selected instead. end fd2 fighter concept; concept never saw use production aircraft; wood summarised state of affairs harvest left france gather .

bac 221

development of concorde harnessed then-new type of delta wing being developed @ rae known ogee or ogival delta design. design aimed improve both supersonic performance through limited span, , low-speed performance through creation of vortices between wing , fuselage increased air velocity on wing , thereby increased lift. in order make full use of effect, wing should long possible, , highly swept @ root. continued studies of basic concept led ogee layout , become apparent series of full-scale flight tests necessary validation.

bac 221 @ fleet air arm museum. forward extension , general curving layout can seen

low-speed testing of concept being provided handley page hp.115. although high-speed performance appeared predictable, dedicated testbed aircraft desired, drag measurements. 1958, rae , fairey began discussions converting 1 of delta 2 prototypes support ogee wing. fairey proposed stretching fuselage further 3 feet better match long planform, wing extending out onto drooping nose. however, calculations showed extension not great enough counter forward moving centre of pressure (cop) resulted extended planform, , there concerns over-wing engine intakes swallow vortex above wing.

during 1960, further development activity disrupted purchase of fairey westland aircraft, assigned further work on conversion project hunting aircraft. accordingly, in july 1960, programme moved bristol , part of larger british aircraft corporation (bac). bristol suggested 2 ways forward, minimal conversion sub-optimal wing no other major changes, or maximal conversion larger 6 foot extension fuselage , taller landing gear more typical of type expected on concorde. both equipped new elliott brothers stabilization system, , have engine intakes moved under wing. minimal conversion considered more of compromise , being less slender , lacking additional fuel capacity maximal option provided for.

in september 1960, agreed maximal conversion proceed; on 5 september of year, wg774 flown bristol s filton facility. following period of detailed design work, re-manufacturing process commenced in april 1961. considerable cost cutting measures , management strategies, such pert, adopted bac in order not overrun on fixed-price contract had been issued work; engineers allegedly frustrated apparent means of further improvement dismissed. on 7 july 1961, newly christened bac 221 completed.

several problems encountered during conversion. newly lengthened landing gear required more hydraulic fluid, required larger reservoir hold it, pump move enough through system, , on through hydraulic system. retaining relatively simple intakes on bottom of wing presented issue airflow engine below, opposed entire compressor face, ducts extended above wing split airflow evenly; produced noticeable bulge on upper surface of wing. no attempt made fit variable intakes. @ high throttle settings, considerable suction inlets generated; in event of sudden down-throttle motion pilot result in air spilling out of intakes, concern because flow above wing , disrupt vortex. small lips added intakes prevent this, proved cause intake buzzing. changes ducts, assisted rolls-royce, addressed issue.

one major advantage of new design larger fuel capacity, has been major problem original fd2. delta 2 had run out of fuel while still accelerating, thereby never reaching full performance. modifications 221 meant not capable of same levels of performance; however, speeds of mach 1.6 attained during test flights. in total, bac 221 featured new wing, engine inlet configuration, rolls-royce avon ra.28, modified vertical stabilizer , lengthened undercarriage mimic concorde s attitude on ground. first flew in form on 1 may 1964. sole 221 used various test flight conducted 1964 until 1973, after aircraft after preserved , placed on public display.