History Brief, by Johan Visschedijk July 7, 2007

Hawker P.1127 & Hawker Siddeley Kestrel F(GA).Mk.1

In 1957, Dr. Stanley Hooker of the Bristol Engine Company and Sir Sidney Camm of Hawker combined their forces in the design of a VTOL-aircraft that led to the well-known Harrier. A Hawker design team led by Ralph S. Hooper made the initial layout and by the end of 1958 the aircraft was conceived in project P.1127. At the same time financial backing was obtained from the NATO and the USA by the Mutual Weapon Development Project, and in April 1959 the manufacture of two prototypes was approved, the contact was signed June 22, 1960. Produced at the Hawker works at Kingston upon Thames, Surrey, the first airframe, XP831, was delivered to the Dunsfold, Surrey, on July 15, 1960, for final assembly and engine tests. The aircraft lifted itself from the grid on October 21, although still tethered. The first free hover was made on November 19, 1960 and the following January the prototype was transported to RAE Bedford, Bedfordshire, were Hawker Chief Test Pilot A. W. "Bill" Bedford made the 22 minute-lasting first conventional flight on February 13, 1961. The first transistion from hover to full wing-borne flight, and back to hover, took place on September 12, 1961. The second prototype, XP836, was first flown conventionally from Dunsfold on July 7, 1961, but unfortunately crashed near Yeovilton on December 14, 1961, after the loss of the port front engine nozzle. Pilot Bill Bedford ejected safely, but the aircraft exploded on impact. Ordered by the Ministry of Supply on November 2, 1960, the first of four P.1127 development aircraft, XP972, was flown on April 5, 1962. Support was gained from West German and the USA and on May 22, 1962, the Ministry of Aviation ordered an additional nine aircraft, UK s/n XS68 to XS696, for delivery to an evaluation unit to be formed at the Central Fighter Establishment at West Raynham, Norfolk. In the FY 1964 the nine aircraft received for procurement reasons the US military s/n 64-18262 to 64-18270, they also were designated XV-6A. The first of the evaluation aircraft, XS688, flew for the first time on March 7, 1964, the remaining eight were all flown by March 5, 1965. In September the type became known as the Hawker Siddeley Kestrel F(GA).Mk.1 (Hawker had merged into Hawker Siddeley on July 1, 1963). The first aircraft was delivered to West Raynham on June 25, 1964. There pilots, ground crew and equipment were gathered to form the Tripartite Evaluation Squadron (TES). The squadron was officially formed on October 15, 1964 and consisted of four pilots from the RAF, two from the German AF, one from the USAF, two from the US Army and one from the US Navy. Additional there were 7 officers and 109 other ranks from all services. The last aircraft was delivered on March 26, 1965. In November 1965, after 938 flights, the TES was disbanded. Six aircraft were shipped to the USA and as XV-6As with US serials participated in the combined Tri-Service trials at NAS Patuxent River, aboard the USS Guam, USS Independence, and USS Raleigh, flown by pilots of US Air Force, Army, Navy and Marine Corps. The USAF flew trials at Edwards AFB, California as well. Hawker Siddeley XV-6A

Hawker P.1127

XP831. First flown October 21, 1960, crashed Paris Air Show, June 16, 1963, rebuilt, last flown October 10, 1972, presently at Science Museum, South Kensington, London. XP836. First flown July 7, 1961, crashed near Yeovilton, December 14, 1961, scrapped. XP972. First flown April 5, 1962, crashed Tangmere, Chichester, West Sussex, October 30, 1962, scrapped. XP976. First flown July 12, 1962, twenty years later scrapped. XP980. First flown February 24, 1963, presently at FAA Museum, RNAS Yeovilton, Somerset. XP984. First flown February 13, 1964, crashed forced landed at Thorney Island, West Sussex, on March 19, 1965, rebuilt, crashed October 31, 1975 at RAE Bedford, presently at Brooklands Museum, Weybridge, Surrey.

Hawker Siddeley Kestrel F(GA).Mk.1

XS688. First flown March 7, 1964, delivered to TES June 25, 1964. Delivered to the USAF as XV-6A 64-18262 on February 19, 1966, presently at USAF Museum, Wright Patterson AFB, Ohio, USA. XS689. First flown May 28, 1964, delivered to TES July 15, 1964. Delivered to the USAF as XV-6A 64-18263 on February 19, 1966, became NASA "521" in February 1967, presently at NASM, Washington, D.C., USA. XS690. First flown August 5, 1964, delivered to TES September 17, 1964. Delivered to the USAF as XV-6A 64-18264 on February 19, 1966, presently at the Museum of Army Aviation, Fort Rucker, Alabama, USA. XS691. First flown September 5, 1964, delivered to TES November 11, 1964. Delivered to the USAF as XV-6A 64-18265 on February 19, 1966, scrapped after trials. XS692. First flown November 7, 1964, delivered to TES January 8, 1965. Delivered to the USAF as XV-6A 64-18266 on January 8, 1966, after trials delivered to NASA Langley as spares support, eventual replaced NASA "520" (see XS694), presently at Hamilton Aerospace Park, Virginia, USA. XS693. First flown November 25, 1964, delivered to TES January 29, 1965, crashed near Stonehenge, near Amesbury, Wiltshire, September 21, 1967. 64-18267 not taken up. XS694. First flown January 30, 1965, delivered to TES March 30, 1965. Delivered to the USAF as XV-6A 64-18268 on February 19, 1966, delivered to NASA as "520" on July 31, 1966, crashed at Wallops Island, Virginia, USA, August 27, 1967. XS695. First flown February 19, 1965, delivered to TES March 26, 1965, crashed at Boscombe Down near Amesbury, Wiltshire, March 15, 1967, presently at Cosford, Shropshire. 64-18269 not taken up. XS696. First flown March 5, 1965, delivered to TES March 26, 1965, crashed April 1, 1965. 64-18270 not taken up.

Specifications (Hawker Siddeley Kestrel F(GA).Mk.1)

Type: Engine: Span: Length: Height: Wing area: Empty weight: VTOL take off weight: STOL take off weight: Max take off weight: Max speed: Climb: Service ceiling: Range (STOL): Range (ferry): Single-seat vertical and short take off and landing ground attack fighter One 15,200 lb {6,895 kg) Bristol Siddeley Pegasus 5 turbofan engine 22 ft 10 in (6.96 m) 42 ft (12.80 m) 10 ft 9 in (3.28 m) 186 sq.ft (17.28 sq.m) 10,000 lb (4,536 kg) 13,000 lb (5,897 kg) 18,000 lb (8,165 kg) 21,000 lb (9,525 kg) 690 mph (1,110 km/h) at sea level, 650 mph (1,046 km/h) at 36,000 ft (10,973 m) 35,000 ft (10,668 m)/min initial; to 50,000 ft (15,240 m) in 4 min 50,000 ft (15,240 m) 220 mls (354 km) at 1,000 ft (305 m), 350 mls (563 km) at 40,000 ft (12,192 m) 2,500 mls (4,023 km)