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ASN Wikibase Occurrence # 206319
Last updated: 30 July 2020
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Type:Willoughby Delta F
Owner/operator:Willoughby Delta Company Ltd
Registration: G-AFPX
C/n / msn: 1
Fatalities:Fatalities: 2 / Occupants: 2
Other fatalities:0
Aircraft damage: Written off (damaged beyond repair)
Location:Caulcott, near Bicester, Oxfordshire -   United Kingdom
Phase: En route
Departure airport:Whitney Aerodrome, Whitney, Oxfordshire
Destination airport:
The Willoughby Delta F (or Delta 8) was a small twin-engined aerodynamic test bed for a proposed flying wing airliner - the Delta 9. The Delta 8 flew in the United Kingdom for a few months during 1939 before being involved in a fatal crash. With the death of the designer, and the outbreak of WWII, there were no further developments.

The Delta first flew on 11.3.39, having already been registered [C of R 9034] on 22.11.38 as G-AFPX. On 14.5.39, piloted by A.N. Kingwill, it was demonstrated at the Royal Aeronautical Society's garden party fly-in at Great West Aerodrome, also at Heston Aerodrome.

On 10.7.39, it crashed at Caulcott near Bicester, Oxfordshire, killing the pilot Hugh Olley and the Delta's designer, Percival Willoughby. The crash was not attributed to the novel configuration but to an ill-designed elevator trim tab that sent the Delta into a dive. Nonetheless, with the death of the designer and the coming of war, no more was heard of this type of flying wing. A contemporary local newspaper reported on the incident (Birmingham Mail - Tuesday 11 July 1939):

Half an hour after leaving Minster Lovell (Oxon) aerodrome in the St. Francis, an all-wing aeroplane which he had designed and which he claimed to be the safest ever flown, Mr. Percival Nesbitt Willoughby, of Filsham Road, St. Leonards-on-Sea, and his pilot, Mr. Hugh N. Olley, of Dolcoed, Doyslyn, Carmarthenshire, crashed to their deaths at Caulcott, near Bicester, last night.

Mr. Willoughby, who was the managing director of the Willoughby Delta Co., Ltd., of London and Witney, Oxon., first conceived the idea of a triple-engined compound-wing type of machine, whose chief features would be light weight, high efficiency and safety, some ten years ago. He saw the culmination of years of painstaking research in the St. Francis—the first all-wing aeroplane —which was a smaller twin-engined machine built merely to demonstrate the all-wing principle.

When it underwent its tests last May the unorthodox 'plane was enthusiastically received by the experts.

The company had in view a much larger aircraft with a load weight of 5,000 lbs., capable of cruising at 240 mph for 6,000 miles with a load of three tons of mail. Alternatively it might be equipped with cabins for 20 passengers and have a range of 4,500 miles."

Registration G-AFPX belatedly cancelled by the Air Ministry post war, on 23.1.46, due to "destruction or permanent withdrawl from use of aircraft". A note on the aircraft's record card states "(Census 1945)"; which indicates that the Air Ministry were only made aware of the demise of G-AFPX after a return (or - considering that they had died six years earlier - the lack of one!) from the last registered owners, in response to the Air Ministry's 1945 census into the existence (or not) of all UK-registered pre-war civil aircraft


1. Birmingham Mail - Tuesday 11 July 1939
2. Hastings & St. Leonard's Observer - 15 July 1939.

Willoughby Delta F G-AFPX at Whitney, Oxfordshire 9.2.39 Willoughby Delta 0371

Revision history:

18-Feb-2018 22:25 Dr. John Smith Added
02-Apr-2020 20:30 Dr. John Smith Updated [Source, Narrative]
02-Apr-2020 20:35 Dr. John Smith Updated [Source]

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