Date:	Tuesday 5 July 1955
Time:	day
Type:	Supermarine 525
Owner/operator:	Vickers-Supermarine Aircraft Ltd
Registration:	VX138
MSN:
Fatalities:	Fatalities: 1 / Occupants: 1
Aircraft damage:	Destroyed
Location:	Idmiston, 2 miles SSE of Boscombe Down, Wiltshire -   United Kingdom
Phase:	Manoeuvring (airshow, firefighting, ag.ops.)
Nature:	Test
Departure airport:	Boscombe Down, Wiltshire (EGDM)
Destination airport:
Confidence Rating:	Information is only available from news, social media or unofficial sources

Narrative:
The third Supermarine Type 508 VX138, built like the others at Supermarine's Hursley Park experimental department, was modified on the production line to closer to Scimitar standards and was redesignated the Type 525. This aircraft was delivered by road to the Aeroplane and Armament Experimental Establishment (A&AEE) at Boscombe Down, Wiltshire, on 25 April 1954. It made its first flight on 27 April 1954 at the hands of Supermarine's test pilot Mike J Lithgow.

The Type 525 was powered by two Rolls-Royce Avon turbojets and fitted with a taller tricycle undercarriage positioned further out on the wings than on the Type 508. It had a conventional tail and rudder surfaces and swept wings. It made its first public appearance at the September 1954 Farnborough Airshow.

The aircraft made further test flights during late 1954 from its base at Chilbolton airfield, Hampshire. In early 1955 it was taken by road to the Hursley Park factory for the installation of a flap blowing system. This was designed to reduce the safe landing approach speed, an obvious advantage for safe operation from aircraft carriers. It also lowered the speed at which catapult launches would be carried out.

The flap blowing system ("super-circulation") on the Type 525 used a device to project a thin jet of high pressure air, bled from an engine compressor, through a narrow slot along the wing trailing edge just ahead of the flap hinges. The Coandă effect then bent the jet of air over the flaps. The improved lift resulted in an 18 mph reduction in approach speed - most useful for carrier-based aircraft.

After returning to Chilbolton by road, the aircraft was flown to the A&AEE on 5 July 1955 for further trials. The aircraft was tested for low speed handling on 5 July. Whilst at 10,000 ft (3,000 m), and unable to recover from a flat spin 20 minutes after take-off, the aircraft spun in from 3,000 ft (910 m) over Idmiston, two miles south-south-east of Boscombe Down. Pilot unable to jettison canopy and ejection seat operating face blind snagged his helmet, delaying his escape further. He finally ejected through reinforced canopy with the aircraft vertical. The pilot sustained fatal injuries in a heavy landing in the seat with parachute only partly deployed. It was destroyed by fire and the pilot Lieutenant Commander Tony A. Rickell, who had ejected just before the crash, died of injuries sustained

1. https://en.wikipedia.org/wiki/Supermarine_525
2. https://www.britishpathe.com/video/first-flight-of-the-supermarines-525
3. Flight Magazine, 15 July 1955 p.73: https://www.flightglobal.com/FlightPDFArchive/1955/1955%20-%200961.PDF
4. https://www.baesystems.com/en/heritage/bristol-175-britannia
5. https://www.thunder-and-lightnings.co.uk/scimitar/profiles.php
6. https://www.thunder-and-lightnings.co.uk/memorial/entry.php?id=242
7. https://www.secretprojects.co.uk/threads/supermarine-scimitar-and-related-projects.23320/
8. https://www.airteamimages.com/supermarine-525_VX138_united-kingdom---royal-navy_115528.html
9. https://www.naval-history.net/xDKCas1955.htm
10. https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_military_aircraft_(1955%E2%80%931959)#1955

Supermarine 525 VX138 at Chilbolton in 1954: Supermarine 525 VX138 displaying at Farnborough Air Show, 11 September 1954:

Date/time	Contributor	Updates
14-Jan-2020 01:43	Dr. John Smith	Added
14-Jan-2020 01:52	Dr. John Smith	Updated [Embed code, Narrative]
07-Jun-2020 15:13	Dr. John Smith	Updated [Source, Narrative]