On 3 June 1966, a newly built

Hawker Siddeley Trident The Hawker Siddeley HS-121 Trident (originally the de Havilland DH.121 and briefly the Airco DH.121) is a British airliner produced by Hawker Siddeley. In 1957, de Havilland proposed its DH.121 trijet design to a British European Airways (BEA ...

jetliner crashed during a pre-delivery test flight near the village of

Felthorpe Felthorpe is a village and civil parish in the English county of Norfolk. Felthorpe is located east of Dereham and north-west of Norwich. History Felthorpe's name is of mixed Anglo-Saxon and Viking origin and derives from an amalgamation o ...

, Norfolk, England, killing all four crew. The aeroplane had entered a

deep stall In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack exceeds its critical value.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', p. 486. Aviation Supplies & Academics, 1997. ...

from which the crew were unable to recover. It was the first loss of a Trident aircraft.

Aircraft and crew

Aircraft

The aircraft involved was a tri-jet Hawker Siddeley Trident 1C, registration that was about to be delivered to

British European Airways British European Airways (BEA), formally British European Airways Corporation, was a British airline which existed from 1946 until 1974. BEA operated to Europe, North Africa and the Middle East from airports around the United Kingdom. The ...

Crew

The crew were pilots Peter Barlow and George Errington, and technicians E. Brackstone-Brown and G.W. Patterson.

Accident flight

The aircraft was making its first flight, which was a routine test flight to enable the aircraft's

Certificate of Airworthiness A standard certificate of airworthiness is a permit for commercial passenger or cargo operation, issued for an aircraft by the civil aviation authority in the state/nation in which the aircraft is registered. For other aircraft such as crop-spray ...

to be issued. There were four crew on board. The aircraft took off from

Hatfield Aerodrome Hatfield Aerodrome was a private airfield and aircraft factory located in the English town of Hatfield in Hertfordshire from 1930 until its closure and redevelopment in the 1990s. Early history Geoffrey de Havilland, pioneering aircraft desig ...

at 16:52. Tests established that the

stick shaker Stick, sticks or the stick may refer to: Thin elongated objects * Twig or branch * Walking stick, a device to facilitate balancing while walking * Shepherd's crook * Shillelagh * Swagger stick * Digging stick * Swizzle stick, used to stir drinks ...

operated at , and that stall recovery system operated at . The crew then disconnected the stall warning systems in order to ascertain the actual margin left after the warning had been given before the aircraft stalled. On this particular flight, the aircraft was being operated with its

centre of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the barycenter or balance point) is the unique point at any given time where the weighted relative position of the distributed mass sums to zero. For a ...

towards its aft limit. Shortly after 18:30, the pilot reported that the aircraft was in a "superstall". At the time, the aircraft was observed to be configured for landing. It was at an altitude of . The nose was seen to pitch up by 30 to 40° before the aircraft turned to port, followed by the starboard wing dropping. Although full power was applied, the aircraft entered into a flat spin, and crashed at

, killing all on board. It was not fitted with an anti-spin parachute. The site of the accident was in a field adjacent to Felthorpe Airfield.

Investigation

The Accidents Investigation Branch opened an inquiry into the accident. The investigation found that accident was the result of the pilot delaying recovery manoeuvres for too long, thereby allowing the aircraft to enter a

from which it was impossible to recover.

References

Sources

*
Deep Stall Disaster
''Flight International'', 20 November 1968 p909-910 {{DEFAULTSORT:Felthorpe Trident crash, 1966 Aviation accidents and incidents in 1966 1966 in England Aviation accidents and incidents in Norfolk Accidents and incidents involving the Hawker Siddeley Trident 20th century in Norfolk June 1966 in the United Kingdom 1966 disasters in the United Kingdom Airliner accidents and incidents caused by stalls