Douglas A/B-26 Invader

Bad day at Biggin

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Firstly, may I point out that in creating this feature on the Biggin incident, I thought long and hard about the possible repercussions arising from bringing this event to life from the archives of aviation history.
On perusing the various aviation forums, I found that there were those self opinionated sorts, that hit the "don't go there" button when questions regarding this accident had been raised.
I feel the incident warrants an in depth look at what really occured on that fateful day and I also feel a duty to those not only killed in the tragedy but to all the relatives and onlookers, who still to this day suffer from trauma associated with experiencing the crash.
No one will ever know for sure, what made Don Bullock perform that disastrous manoeuvre and we may never know why the accident actually happened, but in creating this feature, I have at considerable time to myself managed to collate all the information available, be it from the web the NTSB or via my own investigation, so that you can come to your own conclusions.
There are people who think the subject should be put to bed and bringing it all to the surface again is ghoulish and unnecessary.
I felt that there was enough on-going data in the public domain, accessible by the general public, to safetly create a summary of the accident using both "eye witness" reports and "official documentation" and thus bring an end to the discussion on the topic.
This article is not based on my opinions or speculation.
I have only created this feature because this is a site dedicated to the A-26 Invader, so all stories and events connected with the A-26 are relevent and had my passion lay in another aircraft type, then this would all be academic.
I would like to thank, the Inspector Support Unit at the Air Accidents Investigation Branch, Farnborough House, Berkshire Copse Road, Aldershot, Hampshire, GU11 2HH, for their invaluable help and assistance in supplying data on the accident.

Important note: Due to the overwhelming request to bring this feature back, I have decided to reinstate this feature.

I have not taken this lightly, but after many emails from the people that where there and wanted to tell their story I have allowed the feature to again be viewed as part of this web site.


All information presented on this subject is for general reference only. While every effort has and will be made to insure its accuracy, the information should not be used or relied on for any research or similar use without consulting the writer of the article or the webmaster. Anyone making use of this information does so at his or her own risk and assumes any and all liability resulting from such use. The entire risk as to quality or usability of the information contained within is with the reader. In no event will I be held liable for the use of the information contained within this article.

Personal accounts

Graphic and multimedia evidence

Newspaper reports - Donated by Paul van der Horst

The aeroplane - Double trouble

Tragedy is part of aviation history and it is definately part of Biggin Hill's history.
Since the airfield was first opened in 1917 many of pilots have died in accidents, as opposed to war time exploits, each one adding to the concerns of those who argue that the flight path today should not go over a hospital, school and hundreds of homes. 

In June 1918: Lieutenant Pownall of 141 Squadron took off on a routine searchlight exercise on a clear warm night, minutes later his colleagues heard a loud explosion from the valley. Pownall is dead among the mangled remains of his BE2 and so is a pigeon which caused the tragedy.
"He is the first pilot to die in an accident at Biggin Hill."


Clarification: Re the above

I had a mail from Martin Kent who wrote,

Hi, I have have information that the first pilot to be killed at Biggin Hill as a result of an accident was Captain Francis Reginald Hudson 141 Squadron flying a BE12 6534 on 21st March 1918. If you can help with any details of the circumstances of the accident that would be greatly appreciated.



Lets start at the begining: The accident


The pilot was Don Bullock, a noted pilot of several thousand hours who not only carried his business associate Peter Warren along with 6 passengers in the A-26, but tried to Barrell Roll the Invader on that fateful day at Biggin Hill on September 21st 1980.

There were no maintenance problems found, but the official sources ( Douglas ) say, you "do not" attempt to roll an Invader, let alone at low-level and definately not with 6 passengers on board, even though many have. 


Note: Following the accident, the CAA ruled that only "essential crew" would be carried during air shows and "no passengers".


"If anyone was found flouting this rule, they risked having their display permit withdrawn".



Fact: Don Bullock had asked to practice the fatal roll before the show but was refused.


Fact: An eye witness report stated, that the Invader flew past the crowd right to left, heading south, and as it did so, it climbed and rolled left. When the roll reached the inverted position the nose dropped sharply, and the aircraft continued rolling left before it disappeared flying vertically into the valley. There was no sound of an explosion but a large puff of smoke. The Invader was carrying little fuel, so the onset of stall on this aircraft might have been due to the laminar wing design, which must have been sudden and unforgiving. (see video on page 2.)


Fact: Don Bullock attempted the same manoeuvre on take off at Mildenhall Air Fete the previous May, as he attempted to barrel roll he changed his mind and managed to pull it into a climbing turn, the commentator went very quiet then made some comment to the effect of 'He shouldn't have tried that'.


Fact: Don Bullock also barrel rolled the Invader at the 1980 Leicestershire Aero Club Air Show in late August. It was completed without any problem.


Fact: Don Bullock had practised with an A-26 instructor during the year prior to the accident and had flown the manouevre at shows earlier that season, prior to which he had said that he would not introduce it into his routine until he was thoroughly satisfied that he had perfected it.


Fact: On the day of the crash, a B-25 flew in low and fast over the field, piloted by John 'Jeff' Hawke and Rodney Small, he was also carrying passengers and one young lad in particular had jumped out of the B-25's hatch and ran over to Bullock to ask him if he could take a flight in the Invader as he had never flown in that type.

He died along with six other people.


Also, I have included some shots of Don Bullock flying ' Sally B ' and as you can see, his display routine was unorthodox, at least for todays standards.



Those lost in the Accident:

  • Don Bullock ( Pilot )
  • Peter Warren ( Associate )
  • Arthur Heath of Broadwalk, Heston, Middlesex ( Director of F&H Aircraft )
  • CMSgt Don Thompson ( Ground engineer for the A-26 ) Upper Heyford USAF ground crew.
  • Sgt Mechanic Kevin Vince ( assistant to Thompson ) Upper Heyford USAF ground crew.
  • Gary French of Brighton Close Hillingdon.
  • Roger Russell of Firglen Drive, Yately Hampshire.

Chief Master Sergeant (CMSgt) Don Thompson
( Ground engineer for the A-26 ) Upper Heyford USAF ground crew.





The above four photos were kindly supplied by Victor Blanchard
Victor wrote:

Hi Martin

You’ve probably heard this one a few times, but yes I was there re the above, I was 24 at the time and witnessed the crash. I don’t want to go into that debate anymore but the reason I’m contacting you is I have some photos from that fateful day of ‘Double Trouble’ that someone like yourself and your interesting website might be interested in. There are 4 photos, 2 being particularly poignant of Sgt.Don Thompson who was a passenger on board that day and as you know died a few hours later.

I’m testing the water at the moment(so to speak) because I don’t want to go down that road of copyright/sensitivity issues.

I’ve done a bit research re Sgt. Thompson, his family/relatives are difficult to find.

So if you’re interested in these photos for the website please contact me


Above left, CMSGT Don Thompson
Submitted by Bill Waller ( See link )
During the month September 1980 I visited an Air Show at Biggin Hill, Kent. I photographed Chief Master Sgt Donald Thompson, 20th TFW, who later in the day lost his life as a passenger in what I believe to be an ancient WW II plane. Scant details were published in the national press but later I confirmed the details with the Deputy Commander at Upper Heyford. This photo has laid dormant in my collection ever since and has now been filed digitally on my PC.
I would very much like the family of CMS Thompson to have this shot, which was taken moments before his death. I have written twice to the authorities at Shaw, their base in Sumter SC and have had no response whatsoever. Would you know of an organisation in the US that could assist me in my quest. I am, of course, aware of the time lapse but feel the family would be happy to have this last picture in their collection. I would appreciate your advice and assistance.

The attached file shows two airmen, perhaps discussing the ensuing flight, certainly the last in respect of CMSgt Thompson shown on the left.

I do not have any details of the guy on the right or if he was on the fateful flight in question.

Bill Waller
Sussex England.


From Dwayne A. Thompson

I am the son of Duane L. Thompson, the youngest brother of Chief Master Sargeant Donald L. Thompson. Your website giving the details of that fatefull flight of the A-26 Intruder has been a welcome relief for the Thompson family. We did not have much information regarding this accident. My Uncle gave me his E-8 uniforms when he was promoted to E-9, when I was a boy. He was a hero to me, even though I met him twice. His time served in England kept him from his family in Michigan, USA. Thank you, again for your website. I have shared your website with the rest of the Thompson family, and they are grateful. We do not know the location of his wife, and three children, but I am researching.


Above, another shot of CMSGT Don Thompson ( left )


Regarding the above two shots
I would like to thank you for posting the second photograph of CMSGT Donald Thompson on top of the A-26 Invader. As mentioned in a previous message, Donald Thompson was my uncle. I can confirm that is him on the left. The young gentleman on the right side of the photograph is his only son, Paul Robert Thompson. I have included a photograph of CMSGT Thompson's military funeral in Fort Logan National Cemetery in Denver, Colorado, United States. This photograph captures the airmen preparing to fold the American flag. Seated on the bench in the forefront is Paul Robert, next to his mother, and CMSGT Thompson's widow, Jean Thompson. My father, Duane L. Thompson

Dwayne A. Thompson
Dwayne continues:

Thank you for your response. I have shared your website link with my family members. We are very appreciative of the work you have compiled. We are still searching to locate Uncle Don's children. We understand his oldest child, Gretchen and son, Paul were living in the states. Paul entered the military shortly after his Dad's death. Uncle Don's widow, Jean stayed in England, along with his youngest child, Cynthia. My mother gave me some old contact information that my father received from Aunt Jean many years, ago. My father passed away August 15, 2011, and my found this information among his belongings.

Thank you, again,

Dwayne Thompson
If anyone out there can help Dwayne track down his family he would be extremely greatful





The pilot - Don Bullock


Below, Bullock at the controls of "Sally B"



Above is Don Bullock and his associate Peter Warren (who also died in the crash) prior to the incident.

Below are a series of articles/arguements, for and against the defence of Don Bullock

In defence of Don Bullock

FLIGHT International, 12 November 1980

SIR—After reading your editorial on Air Show Safety (Flight, October 25), I felt that it cast an oblique slur on Don Bullock, the pilot of the A-26 which crashed at the Biggin Hill Display. In view of the fact that a dead man cannot defend himself, perhaps I may be permitted to comment.

I flew withDon at a good many air shows, and I never saw him do anything which I considered reckless or dangerous. He thought far too much of the aeroplanes to risk them. The A-26 crashed whilst Don was carrying out a simple manoeuvre in an aircraft with which he was thoroughly familiar. The cause of t he accident has not yet been established, and until the official enquiry by the CAA has reported its findings, neither the editorir! staff of Flight nor anyone else is in a position to pass judgement.


Pippingford Park




Pilots medical history cited in air display accident inquest

FLIGHT International, 31 January 1981      
A PILOT who crashed during a display is said to have had a history of psychiatric illness and, in at least one doctor's judgment, should not have been flying—allegations which brought swift reaction from British aviation authorities and commentators. In an inquest on the seven people who died when a Douglas A-26 Invader crashed at Biggin Hill last September (see Flight, September 27, page 1243), a consultant physician has testified that pilot Capt Don Bullock suffered from depression for many years and received treatment in 1975 and 1976.
A verdict of accidental death was recorded on Bullock and verdicts of unlawful killing were returned on four of the six passengers; two further passengers—both US Servicemen—are subject to American inquiries.
The aircraft came down at the end of a barrel roll, striking the ground in a valley at a level much lower than the adjacent airfield. The Invader was not registered in the UK and was maintained under US regulations limiting its use to aerial survey work.
Consultant physician Dr Anthony Hall of London's Hospital for Tropical Diseases provided Bullock with a certificate for insurance to show that he had been temporarily unfit to fly for medical reasons in 1976. "I wish now that I had given him a certificate that he was unfit to fly for ever, because of his gross exhaustion and depression," Dr Hall told the inquest.
"I could say he was mentally disturbed and that should have precluded him from flying. I was very shocked that he should be flying at all." UK Civil Aviation Authority (CAA) chief medical officer Dr Geoffrey Bennett said that the CAA had known of Bullock's psychiatric history and that he took tranquillisers. Senior CAA consultant psychiatrist AVM O'Connor reported that Bullock had been symptom-free, off medication for a month and was fit to fly before his licence was renewed in July I960. Coroner Dr Mary McHugh said that she would invite the CAA. to establish a committee to monitor airdisplay programmes and standards.
Dr Hall went on record afterwards as saying that his clinical experience indicated that a high proportion of pilots were physically and/or mentally unfit to fly. He was not satisfied that CAA medical checks were sufficiently stringent. "Pilots should be grounded if they drink or smoke more than small quantities," he is reported as saying, since "smoking and alcohol can each impair visual acuity." Obese pilots should be grounded, he said.
CAA senior aircrew medical examiner and aviation-medicine specialist Dr Ian Perry does not agree with Dr Hall's conclusions about Bullock's state of health or his sweeping generalisations about "inadequacies" in present pilot medical screening.
Hall "has no aviation medicine background and is therefore unfit to comment in detail on these subjects," says Perry. Pilots who are referred to Hall see him only for tropical diseases screening. Dr Perry, who has examined Bullock, says that he did not have depression, but had been on tranquillisers to help him sleep during a period of overwork. He adds that Hall has made statements before "which indicate an obsession with alcoholism," a disease and the effects of which, Perry insists, will be discovered by any experienced CAA examiner during normal six-monthly medical checks. Though the best of safety nets will let through a few who should not pass, "pilots have continuously to prove themselves on flying checks; this catches any the medical net misses," says Perry.
Dr Hall has remarked that some pilots sent for checks had symptoms of "partial blindness." Perry says this description can be applied to pilots who are tested without spectacles, but are cleared to fly using them. The general feeling at the CAA and at the British Airline Pilots' Association is that Hall has taken isolated medical cases out of context, exaggerates the significance of the detail, and implied that present checks take no account of certain cases. Dr Hall has spoken on subjects in which he is not a specialist, including non-medical ones: "stunt flying should be banned," he pronounced in a BBC radio interview.



The Invader accident: in defence of the pilot

FLIGHT International, 14 March 1981

SIR—One of the most striking aspects of the Invader accident has been the inordinate amount of publicity given to it, much of which has been inaccurate and emotive. Dr Anthony Hall (Flight, February 21) adds fuel to the fires of meaningless discussion with his inflammatory and grossly erroneous statements. The jury's verdict was not in any way related to the question of mental health, but was specifically concerned with the absence of appropriate "paperwork." Although this aircraft was not expressly cleared for aerobatics, that does not necessarily mean that it was unsuitable for, or incapable of, limited aerobatics such as barrel rolls. This is borne out by the fact that this particular aeroplane had performed this manoeuvre many times before, both in practise and during air shows, and I understand that the type is similarly flown at displays in the Americas, just as it was on occasion when in military service. It seems likely that if application had been made to the FAA some form of approval for limited aerobatics would have been given.

It was made clear at the inquest that the unfortunate verdict arrived at by the jury was based effectively on a technical point of legality. The only "mental" aspect one can possibly construe from this is the oversight of the owner/operator/pilot in not ensuring that the "paperwork" was appropriate to the intended flight. In this "paper-shuffling" world of ours, how many of those of us who fly have not been guilty of some such oversight at some time or other?

During the past two air show seasons there have been four major accidents in addition to the Invader, all involving relatively high-performance military aircraft of four different types operated by as many different air forces. All occurred in this country and yet not one resulted in the hue and cry which has followed the A-26 crash, not even the Red Arrow Hawk which hit a yacht's mast at Brighton. Yet each one was as potentially catastrophic as the Invader could have been. The reason must be that the Invader carried passengers and crashed in the full glare of the cameras, resulting in emotive reports on such things as low-flying, old aeroplanes, aerobatics, passengers, the Biggin valley and other side issues irrelevant to this accident. The Invader did not crash because it was low-flying; this aircraft can gain height easily during the rolling manoeuvre. Many older aircraft are regularly flown at air displays and some are "aerobatted." The Invader was not manoeuvring in the valley—it crashed in it because the valley was underneath it at the time of trouble. Additional restrictions at air shows arising from these aspects would be over-reactive and fortunately seem unlikely.
The most important factor in this accident is the question of passengers and sensibly it is this feature which has preoccupied those involved in air show affairs. Again, one must be wary of "blanket" rules. An aerobatic routine is obviously different from an "historic type presentation" and thus the risk factor is different, justifying different rules. In certain cases carrying a "non-operating" crew member such as an engineer is reasonable, and provision must be made for this in the new rules which are bound to apply by next season. In fairness it must be said that some of those on board the A-26 were engineers who dedicated a considerable amount of their spare time to that aircraft and a flight was recompense for their devotion. Several of them had flown and been rolled previously in the A-26 and they knew quite well that they were not due for a sober saunter round the circuit.

The implications suggested in Dr Hall's letter are obvious, but that fatal roll was not an unrehearsed sudden notion. Bullock had practised with an A-26 instructor during the previous year and had flown the manoeuvre at shows earlier that season, prior to which he had told me that he would not introduce it into his routine until he was thoroughly satisfied that he had perfected it. At the Biggin briefing and at lunch before the show, the Don Bullock I talked and joked with was the same Don Bullock I had known for years. At briefing the early takeoff he requested was refused, but his "slot" time was still adequate for the barrel-roll provided that he reduced his other "passes." As he virtually went straight into a climb for the roll, presumably this is what he intended.
Only the Department of Trade investigators can come to the most realistic conclusion, but with no survivor or flight recorder it will hardly be positive. In the meantime Dr Hall's misleading statements are merely a time-wasting hindrance which serve no purpose except to rub salt into a deep wound already felt by Bullock's family and Jriends.

Sussex TN31 7NL



.....But was the aeroplane really suitable for aerobatics ?

FLIGHT International, 14 March 1981

SIR—The continuing investigation of the fatal B-26 (A-26) crash at Biggin Hill seems to ricochet from one extreme to another without pausing to examine the basic characteristics of the aircraft involved- The description of the pilot has run from that of an unflappable ace to borderline psychotic, and the basic fault charged to the aircraft has been that of being registered and maintained as an American aircraft and not British with a limited permit to fly. What surprises me the most are the casual references made to the fatal barrel role.
The aircraft was licensed under Type Certificate LTG-3, which sets the operating limitations to those found in the applicable flight handbook.
The pilot has been described as being thoroughly familiar with the aircraft and performing a simple manoeuvre. This familiarity seems to cover only the location of all the taps, levers and hooters. The applicable USAF Flight Handbook, T.O. IB-26-1, clearly states in Flight Characteristics, section VI, page 6-3, Manoeuvring Flight, that acrobatics are prohibited, and in section V, Operating Limitations, page 5-4, Prohibited Manoeuvres that rolls are strictly prohibited. It makes no difference who is the pilot or what agency inspects the aircraft if the basic capabilities are ignored.

David M Kubista

2245 E 3rd Tucson
Arizona 85719


Pilot fitness—the debate continues

FLIGHT International, 25 April 1981

The Invader Accident As reported in Flight on March 14 (page 711), the UK Department of Trade Accidents Investigation Branch air-safety bulletin points out that Capt Don Bullock "had undergone treatment for a depressive illness in June 1980. He was subsequently examined by an aviation psychiatrist and issued with a Class 1 medical certificate in July 1980." This is believed to be the first time that an official body has referred to a pilot's mental health in an accident report. The medical and physical fitness of pilots continues to be a topic for correspondents:

SIR—You are performing a public service by allowing full debate in your columns on the Invader accident at Biggin Hill, in which Donald Bullock and his six passengers died. Keith Sissons (March 14), an airline pilot, claims that the Jury's verdict that the four UK passengers were unlawfully killed "was not in any way related to the question of mental health, but was specifically concerned with the absence of appropriate paperwork." the Jury was not asked to explain its verdict, but probably returned the verdict of unlawful killing because Dr Geoffrey Bennett of the CAA, three other witnesses and I gave evidence that Bullock had been mentally ill, seen psychiatrists over many years and had been taking tranquilliser drugs. Also, the Coroner, Dr Mary McHugh, told them that Bullock, having accepted that he could not have time for the roll, appeared to carry out the manoeuvre in a "rather stubborn manner." She told the Jury: "We know that he was a controversial pilot and not an experienced acrobatic pilot. The plane was only registered for surveying purposes and other pilots knew this.

That may, in your mind, suggest recklessness." Bullock had refused to join the Historic Aircraft Association, a voluntary body, because he would not be bound by its rules on flying and had been warned for low flying at displays. Dr McHugh added: "He was anti-authority in that he refused the restrictions of the Historic Aircraft Association and perhaps that says something of his personality." My detailed notes at the Inquest reveal that one witness (whose father died in the crash) said: "Don's health was a problem, all his friends knew this. He was very upset by the recent death of his father, and his friends decided to talk him into safety." It is unfortunate that legal proceedings (including Inquests) are not taperecorded and published. The book Aviation Medicine (vol 2, p 216) says "Disregard for Society's rules is a cardinal symptom of personality defect . . . the great majority of personality disorders will not respond to treatment, so that once a man is adjudged unfit by reason of personality disorder, the embargo is permanent."
CAA statistics show that mental illness is second only to cardiovascular disease in the premature career termination league. I criticise' John Biflen, the Secretary of State for Trade, for refusing my request for a Public Inquiry where all doctors and pilots who knew Bullock could have been crossexamined and all his flying and medical records been published. I claim that there has been a cover-up with respect to Bullock, the Invader and their safety of air shows. During my tour in Vietnam in the US Army, I was a doctor for many brave men wounded in battle.
Bravery by pilots in battle is totally distinct from the antics of pilots who do dangerous stunt flying for cheap thrills.

Dangerous stunt flying, like public hangings, appeals to the mentally immature and should also be abolished.
Tropical Diseases Consultant Physician
London NW1 OPE


The Invader accident, no medical cover-up .

FLIGHT International, 16 May 1981

SIR—I feel that the time has come to stop all the nonsense concerning this tragic accident.

Certain persons' vitriolic attacks on a dead man's personality and character give the impression that these people knew Capt Bullock well. They had, in fact, not sen Don Bullock for many years, and base all their comments on other people's observations, many of which are erroneous.

Don Bullock had been misdiagnosed, mistreated and was not suffering from any illness at the time of the accident. He was, in fact, better than he had been feeling for a long time. It can be clinically proven that he did not have a depressive illness at all, so certain persons are quite professionally out of order and wrong on that score. He did not have a personality defect, and his health was not a problem to anyone except a certain Dr Hall. Aeroplanes will stunt fly for as long as t h e r e are aeroplanes, and sadly accidents will continue to occur. Should we stop car racing, motor-cycling, hang gliding, autocross, parachuting, etc?

I understand from those who know that an Invader will happily roll all day well within its operating envelope. What we will never know is whether one of those passengers came loose and fell on to one of the control systems at a critical moment in that fatal roll. This would seem to make sense in light of the films taken and subsequent analysis by those who know more about it than Dr Hall or I.

There have been other fatal accidents in recent times which deserve more fuss and bother than this sad affair has caused. There has been no cover-up to. my knowledge: why should there be? There have been, however, too many unqualified people making unqualified and unprofessional remarks about subjects they know very little about. Empty vessels always makethe most noise.

Dr Ian Perry

19 Cliveden Place

London SW1W 8HD



.....and unconstructive generalisations

FLIGHT International, 16 May 1981

SIR—While considering myself unqualified to comment on the aeromedical aspects of Dr Hall's various statements and letters concerning the Invader accident, it would seem to me that there are many people greatly more qualified than he on those areas of aviation medicine in which he seems to consider himself something of an expert.

But he is totally over-reaching those areas of his professional or technical competence when he writes "Dangerous stunt flying appeals to the mentally immature and should be abolished." If anything is immature, it is making these bald statements of such fantastic generality that it is difficult to see what he might be trying to get at. Is he trying to say that all display flying should be banned, whether for the demonstration of aircraft or for public entertainment? Since any display is intrinsically more dangerous than straight and level flying at height, he probably is. If so, let us not confine the vital lessons which must be learned from the Invader accident within the much broader suggestions he is making. Of course display flying is dangerous, as is, to a certain extent, anything to do with flying. But it is unnecessarily emotive to bandy around expressions such as "dangerous stunt flying," particularly at a time when various groups of notably mature and sensible pilots and show organisers are meeting to make all forms of flying display as safe as possible. By all means we must learn from Biggin Hill, but the ill-informed and emotional approach of Dr Hall in non-medical areas is unconstructive, not to' say unnecessary, when much is being done that is constructive.

Richard Goode

1 Manchester Square



...........And the conclusion

FLIGHT International, 14 March 1981

No further inquiry into UK air show crash

THE UK Department of Trade Accidents Investigation Branch (AIB) has no plan to order an inspector's investigation into the cause of the Douglas B-26 (A-26) Invader crash in which seven people died during an air display at Biggin Hill last year. The test AIB air-safety bulletin published this week says that after pulling up into a climb the Invader rolled until inverted, when it pitched nose downwards; whilst descending its rate of roll appeared to slow down." According to an operating manual recovered from the wreckage, says the bulletin, aerobatics were not permitted. The Invader continued "rolling to the left at an increasing rate and, wingtip vortices still visible, dived steeply into the valley beyond the end of the runway. [It] continued rolling past the wings-level attitude and . . . still rolling with ailerons applied in the correct sense . . . it crashed.

"Its attitude was about 60 nose down and steeply banked to the left. The aircraft was structurally complete, the flaps retracted and both engines were developing power." Two restrictions in the FAA airworthiness certificate stated that the Invader "did not comply" with Icao international standards and that "special permission
must be obtained from foreign countries for flights over their territories.

There was no record of any permit being issued by Britain's CAA. It was not possible to establish the Invader's c.g. or the precise distribution of its load. The pilot was issued with a Class 1 medical certificate in July 1980, the bulletin points out, after undergoing treatment for a depressive illness during the previous month.

Film of the accident was broadcast all over the world and correspondence in the aviation press (see pages 764- 765 this issue) continues to focus attention on the crash. A coroner's inquest considered that the pilot died accidentally and that the six passengers were unlawfully killed.



What the experts say ( Douglas Aircraft Company )
Pilot's Handbook for Army Models A-26B and A-26C airplanes.
AN 01-40AJ-1
Page 39.

(1) Loops
(2) Spins
(3) Rolls
(4) Inverted Flight

Page 53
Paragraph 15.
Acrobatics are stictly prohibited.

T.O. 1A-26A-1 (Formerly T.O. 1B-26K-1)
Section 5, Operating Limitations
Page 5-5
Spins or acrobatic maneuvers are prohibited.


The symmetrical load factor capability is 4.4G from the minimum flying weight to 33,000 pounds, decreases linearly to 3.75G at 36,000 pounds, then is constant to the maximum gross weight. Etc. Etc.

The rolling pullout load factor capability is 3.2G from the minimum flying weight to 33,000 pounds, constant to the maximum gross weight.

Section VI, Flight Characteristics
Page 6-3

Acrobatics are prohibited in this aircraft.

Air Accidents Investigation Branch full Report with associated Photos

Air accident investigation report summary
Bulletin 2/81 EW/C717
Aircraft: Douglas A-26C (Invader) N3710G
Date and time (GMT): 21 September 1980 at 1514 hrs
Location: 1/3 mile beyond end of runway 21 at Biggin Hill Aerodrome,Kent
Type of flight: Display
Persons on board: Crew - 1 Passengers - 6
Injuries: Crew - 1 (fatal) Passengers - 6 (fatal)
Nature of damage: Aircraft destroyed
Commander's Licence: Commercial Pilot's Licence (UK)
Commercial Pilot's Licence (USA)
Commander's total flying experience: Over 8,000 hours (+200 hours on type)

The aircraft was due to take part in a Battle of Britain Air Display and was programmed to take-off and go straight into a display lasting eight minutes.
During the display briefing, which was held on the morning of the show, the pilot of the Invader asked if he could take-off early prior to the commencement of his display. No explanation was given for this request, nor did the pilot give any indication at the briefing as to what manoeuvres he intended to include in his display.
A suitable time in the programme for an earlier take-off could not be found and the pilot accepted the arrangements as originally scheduled."