ASN Wikibase Occurrence # 74458
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| Date: | Sunday 7 June 1942 |
| Time: | |
| Type: |  Handley Page Halifax Mk II |
| Owner/operator: | TFU RAF |
| Registration: | V9977 |
| MSN: | |
| Fatalities: | Fatalities: 11 / Occupants: 11 |
| Aircraft damage: | Destroyed |
| Location: | Lower Lydbrook, Welsh Bicknor, 8 mi SSW of Ross-on-Wye, Herefordshire -
 United Kingdom
|
| Phase: | En route |
| Nature: | Test |
| Departure airport: | RAF Defford |
| RAF Defford |
Halifax V9977 of the Telecommunications Flying Unit, Royal Air Force, was on a flight from its base at Defford, testing the top secret H2S ground mapping radar system. It carried a flight crew of seven RAF personnel and four technical experts.
A fire started in the starboard outer engine and spread to adjacent fuel tanks. The pilot sought to make a forced landing on flat ground near the River Wye, but before he could do so the wing structure burned through and the outer portion of the starboard wing broke away.
The Halifax rolled over and dived five hundred feet to the ground. There were no survivors.
The RAF investigation found that the fire was caused by the improper tightening of a tappet valve nut which had unscrewed in flight, causing excessive valve opening and the failure of the valve stem. This allowed fuel to leak out of the rocker cover and ignite inside the engine nacelle.
One of the civilian scientists aboard the aircraft was Alan Blumlein, an electrical engineer and gifted inventor who is regarded as one of the most significant scientists of the 20th century. He held 128 patents for inventions in the fields of telecommunications, sound recording, radar, and television. He was the inventor of the stereophonic sound system.
The eleven crew that were killed were named as:
First Pilot: P/O Officer D.J.D.Berrington (115095)
Second Pilot: F/O A.M.Phillips (44185)
Crew:
Observer. F/Sgt G. Millar (751019)
F/Eng. LAC B.D.C.Dear (571852)
WOp/AG. Aircraftman II, B.C.F. Bicknell (1271272)
Passengers:
S/Ldr R.J.Sansom (33372) (Attached T.R.E.)
P/O C.E.Vincent (110285) (Attached T.R.E.)
Mr. G.S.Hensby, Civilian T.R.E.
Mr. A.D.Blumlein, Civilian E.M.I.
Mr. C.O.Browne, Civilian E.M.I.
Mr. F.Blythen, Civilian E.M.I.
Details:
There have been huge amounts of text about this crash. So, I shall try to just cover the key points.
Halifax V9977 had been sent to the Telecommunications Research Establishment (TRE) at RAF Defford, to be used as a flying testbed for the H2S radar.
On the afternoon of 7 June 1942, one of its engines caught fire and led to the aircraft crashing near the Welsh-English border, killing all eleven crewmembers. Among the dead was Alan Blumlein of EMI, who was well known as the inventor of Stereophonic sound recording and the 405-line television system used in the UK until 1985.
Investigators determined that improper engine maintenance/assembly procedures caused the accident. It remains the deadliest crash in the history of military test flight in the UK.
At a meeting on 23 December 1941, the Secretary of State for Air, Archibald Sinclair, directed the TRE should direct their work on H2S radar towards the new four-engine bombers, Philip Dee, B J O'Kane and Geoffrey Hensby visited the Aeroplane & Armament Experimental Establishment at Boscombe Down to examine the available aircraft and concluded that the Halifax had the best possibilities for mounting the scanner in different locations for testing.
V9977 landed at RAF Hurn on 27 March 1942 already modified with the perspex radome. The electronics had been assembled at Leeson House as early as January and was being tested in Bristol Blenheim V6000. A second example was fit to V9977 by 27 March, awaiting the new hydraulic scanner from Nash & Thompson which arrived on 16 April. After some debugging, the system was operational the next day, but performed very poorly, with towns becoming visible at only 4 to 5 miles (6.4 to 8.0 km) from an altitude of 8,000 ft.
It was during this period that plans were made to move the TRE away from its exposed location on the English south coast to a more inland location. After considerable searching, Malvern was finally selected, and the TRE moved en mass' in May 1942. Their experimental aircraft moved from Hurn to RAF Defford. Further work on the system continued to improve the effective range, and by early June they were achieving 25 to 30 miles (40 to 48 km).
On the weekend of 6 and 7 June, Lovell and the team met with Alan Blumlein and two of his associates from EMI to examine the system with an eye to beginning production. After the EMI team left to return to their hotel, Lovell flew in V9977 and received strong returns from Gloucester, Cheltenham, and several other towns at previously invisible ranges.
The EMI team decided they should see this for themselves and took off in V9977 at about 2:50 pm on the 7th heading for the Bristol Channel. At 4:20 pm the aircraft was seen over the Forest of Dean with its outboard starboard engine on fire. Shortly after, the left wing broke off and the aircraft rolled over and crashed in a field on the Courtfield Estate in Lydbrook near Welsh Bicknor on the north side of the river Wye. All aboard were killed.
News of the crash did not reach Defford until 7:35. At 9 pm, Lovell and O'Kane were driven to the site to retrieve the top-secret Cavity Magnetron from the wreckage.
Due to the secret nature of the aircraft, for many years the only information available on the crash was a single index card at the Ministry of Defence that stated the accident occurred when the crew attempted to restart a failed engine which then set on fire. The extinguishers did not work, and it appeared that the bottles had not been filled, and it was suggested they might have been delivered empty and never checked. They attempted to restart the engine to supply power for "special equipment to enable experiment to be continued". The lack of detail led Blumlein's wife and Issac Shoenberg, head of EMI's research division, to suspect sabotage.
In the 1980s, members of the Royal Radar Establishment, which had taken over the TRE in 1953, began their own investigation. This was led by W.H. Sleigh, who retired in 1984 and spent the next year meticulously following up every lead. Among the bits of evidence was a series of interviews with the witness to the crash, who narrowly missed being hit by the aircraft, and a former Rolls-Royce engineer who had examined the engine after the crash.
While the pilot was experienced, he was new to the Halifax with only 13 hours on the type. The rest of the crew were all inexperienced. There were several design flaws with the early Halifax that also contributed to the crash; the fuel valves to the engines were on the wrong side of a fireproof bulkhead, as were the extinguisher bottles. Additionally, the controls to cut off fuel to the engines were placed in a difficult to reach position far behind the cockpit.
But the primary reason for the accident was a change that was made by Rolls-Royce shortly after V9977 entered service. Rolls had noticed that the tappet valves on the engine tended to work loose in service, which was potentially dangerous. To keep them in the proper locations, they had begun to install the valves with slightly less clearance in order that that would reach the proper location in service. This was easily accomplished in the factory, but for existing engines the lock nuts holding the valves in place had to be removed, 48 on each engine, the valve adjusted, and the nuts re-tightened.
This procedure was applied to V9977 shortly before its fatal flight. One of the nuts on the engine had not been properly tightened and came loose in flight. The valve began to work its way loose and eventually broke off. This allowed the fuel-air mixture entering the engine to flow into the area under the rocker cover and catch on fire. Although the engine failed, the propeller kept it rotating, operating the fuel pumps, and continuing to spray new fuel into the fire.
The fire eventually worked its way back through the fuel lines and into the main fuel tanks. The flight engineer had to cut off the fuel supply using the controls in the fuselage, but never made it. The fire apparently broke out at an altitude of 15,000 feet, more than enough to bail out, but no one left the aircraft. It is suggested that the crew had parachutes, but the observers did not, so they decided to remain with the aircraft and perform a forced landing. They almost made it; the aircraft did not break up until about 350 feet.
Crew:
P/O Douglas John Davies Berrington 25yo 115095 RAFVR. Pilot. Killed. 1
F/O Algernon Michael Phillips 21yo 44185 RAF. Co/pilot. Killed. 2
W/O Gavin Millar 751019 RAFVR. Obs’. Killed. 3
LAc Brian Douglas George Dear 20yo 571852 RAF. Flt/Engr. Killed. 4
Ac2 Bernard Charles Frederick Bicknell 1271272 RAFVR. W/Op. Killed. 5
Passengers:
S/Ldr Ronald John Sansom 24yo 33372 RAF. Attached T.R.E. Killed. 6
P/O Clifford Edward Vincent 110285 RAFVR. Attached T.R.E. Killed. 7
F/O Geoffrey Spencer Hensby 24 RAFVR. Attached T.R.E. Killed. 8
Mr. Alan Dower Blumlein Civilian Scientist E.M.I. Killed. 9
Mr. Cecil Oswald Browne Civilian Scientist E.M.I. Killed 10
Mr. Frank Blythen Civilian Scientist E.M.I. Killed 11
Burial:
1 Llanfair Kilgeddin (St Mary) Churchyard. Family Enc’. NE of church. Mons’.
2 Hereford Cemetery. Plot A. (C of E). Grave 5620.
3 Stonehouse Cemetery. Section B. Grave 483.
4 Upper Clatford (All Saints) Churchyard.
5 Harrow (Eastcote Lane) Cemetery. Section N. Grave 30.
6 Steyning (St Andrews) Churchyard.
7 Newquay (Fair Park) Cemetery. Grave 131.
8 Farnborough Cemetery. Section C. Grave 19.
9 Ross & Whitchurch. Rural district.
10 Ross & Whitchurch. Rural district.
11 Ross & Whitchurch. Rural district.
Wreckage:
An obvious scar and large indentation can still be seen. However, there is nothing to signify what caused the large scar, due to the location being in an open field with the well-known footpath that runs not more than 50 yards from the site which is on private land.
Memorials:
CWGC Headstones (Military crew)
Private family headstones
A memorial was built next to the site, with a memorial service on 10 June 2019; the memorial was mostly due to an employee of the Hereford Times, with help from the EMI Archive Trust.
Blue Plaque erected in 1977 by the Greater London Council at Alans former home in Ealing.
Additional Information:
P/O Berrington was the son of Major John Spencer Davies Berrington and Alice Christine Davies Berrington, of Bettws Lodge.
F/O Phillips was the son of Group Captain Algernon Wynne Pendennis Phillips, RAF, and Stephanie Phillips; husband of Gwenyth Maude Phillips, of Wraysbury, Bucks’.
Lac Dear was the son of Henry and Olive M. Dear, of Anna Valley. S.E. part. His brother Robert Henry also made the ultimate sacrifice.
S/Ldr Sansom was the son of Charles Henry and Sophia Sansom, of Steyning.
P/O Vincent was the son of Edgar Vincent and of Annie Muriel Vincent, of Saltash. B.Sc. (Lond).
F/O Hensby was the son of Frederick Charles and Gertrude Agnes Hensby, of North Farnborough. B.Sc, Hon. Employed at the Telecommunications Research Establishment.
Mr Cecil Browne B.Sc.; of Mead Cottage, Chalfont St. Peter, Buckinghamshire. Son of Frank and Jessie Martha Browne, of 41 Creffield Road, Ealing, Middlesex; husband of Margaret Winifred Browne.
Sources:
1. Air Britain: RAF Aircraft T1000 - V9999, published 1997
2. http://www.testflyingmemorial.com/1940-45.htm
3. https://www.sungreen.co.uk/Lydbrook/Halifax_WWII.html
4. https://en.wikipedia.org/wiki/Alan_Blumlein#Death
5. http://www.rafcommands.com/archive/10514.php
6. http://ww2talk.com/forums/topic/18817-the-worst-ever-flight-test-accident/
cwgc.gov
www.findagrave.com
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 23-May-2010 22:15 | angels one five | Added |
| 23-May-2010 22:20 | angels one five | Updated [Source, Narrative] |
| 03-Jan-2012 06:00 | Uli Elch | Updated [Aircraft type, Registration, Operator, Location, Departure airport, Source, Narrative] |
| 06-Jan-2013 23:26 | angels one five | Updated [Operator, Narrative] |
| 07-Jan-2013 00:19 | angels one five | Updated [Narrative] |
| 05-Sep-2014 22:52 | angels one five | Updated [Aircraft type, Location, Departure airport, Destination airport, Narrative] |
| 23-Dec-2014 22:26 | Dr. John Smith | Updated [Location, Source, Embed code, Narrative] |
| 23-Dec-2014 22:27 | Dr. John Smith | Updated [Location] |
| 08-Jan-2016 15:05 | JIXN | Updated [Operator, Narrative] |
| 01-Jun-2022 13:36 | Davies 62 | Updated [Source, Narrative] |
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