AAPT Conference 2007

The role of the autopsy in the investigation of fatal aircraft accidents

Fatal air accidents have declined over the past 25 years thanks in part to the detailed investigations into air crashes by aviation pathologists.

Fatal air accidents have declined over the past 25 years thanks in part to the detailed investigations into air crashes by aviation pathologists. At the Association of Anatomical Pathology Technologists’ conference in Glasgow last September, Wing Commander Graham Maidment from the Department of Aviation, RAF Centre of Aviation Medicine, gave a fascinating insight into how pathological findings from the autopsy of the victims of a fatal aircraft accident provide an essential component of the overall investigation of the accident. The findings may assist in determining the cause of the accident, or may provide information on the survivability issues which may promote flight safety.

One of the first cases of aviation pathology where knowledge gained by investigation was used for preventative purpose, was in 1908 when Lt. Thomas Selfridge of US Army was killed while flying with one of the famous Wright brothers. An autopsy revealed that death was due to fractured skull Taking this into account, Lt. Henry Arnold, who was entrusted with further flying wore a football helmet as a precautionary measure.

Since then investigation of air crashes by aviation pathology has developed through international research and collaboration. In the UK an investigation into a fatal air crash is undertaken by at least two bodies, the Coroner or Procurator Fiscal and the UK Air Accidents Investigation Branch (AAIB) which is part of the Department for Transport. The Coroner investigates the basic facts: the who, what, why, when as well as causes of death. The AAIB has a broader remit to investigate causation, survivability and what lessons can be learnt "to improve aviation safety by determining the causes of air accidents and serious incidents and making safety recommendations intended to prevent recurrence".  The RAF’s Board of Inquiry has a similar role to the AAIB but investigates accidents involving military aircraft.

Maidment explained that the first considerations will be similar to those of APTs in mass fatality accidents, the mortuary. Plane crashes can occur in difficult and remote terrain so it may be a challenge to recover bodies. Can local mortuaries cope with a large number of fatalities? If not, a temporary mortuary needs to be organised. Storage is a concern, especially with the number of potential body ‘fragments’. Security systems need to be in place to deal with large and diverse number of personnel such as police and investigators. With the personnel comes practical issues like parking, catering and reception areas. X-ray facilities are also necessary on site as part of autopsies.

The next big question is who has died. Reconstruction can help relatives identify victims but that is of course dependent on the level of trauma to the bodies. Identification becomes far more difficult in cases of fire, high-level trauma, body fragmentation or the accident has taken place at sea and there is delay in recovering bodies.

In the majority of cases there will be multiple injuries that require pathological analysis. The demonstration of patterns of injury, toxicological findings and assessments flying clothing, the aircraft controls or the flight environment may all contribute to the understanding of the accident and the prevention of similar deaths in the future. For example, injuries caused by harnesses will be of particular interest to evaluate their effectiveness, and whether they hindered or enhanced survival. If someone had survived the crash but died of the ensuing fire could they not get out in time and if so why not? Were the harnesses preventing those onboard from escaping in which case the design needs to be researched for improvement.

The aim of autopsy, as required by international bodies, is to determine cause of death, to evaluate the effects of environmental stress of flight on the fatalities, to correlate injuries with events during accident and to look for any pre-existing diseases or factors which could cause sudden incapacitation. Such an approach to autopsy takes in many different details, history of flight, type of aircraft, medical history of individuals, state of safety equipment and the nature of the crash sites - the latter covered by detailed photography. The pathologist will also need to know how the body was recovered, for example, were some of the injuries caused by fireman cutting bodies out from the plane? In a tiny minority of cases clues will point to the possibility of an accident being deliberately caused – whether through suicide, sabotage or homicide.

X-rays will be taken to detect unidentified fractures and to visualise any metallic or foreign bodies embedded in the soft tissues especially when blast is suspected. They can also help in establishing the age in case of unidentified bodies.

An aviation pathologist will assess whether injuries happened ante-mortem or post-mortem. Burns can be caused in a number of different ways, in a blast or lying in aviation fuel. Fracture of vertebrae and condition of intervertebral discs provide useful information of the direction of the forces operating in relation to bodies. Analysing G-force and whiplash injuries will determine the direction of the crash, an impact moving ‘upwards’ will cause a certain type of spinal-related injuries to the head that will be different to a ‘head-on’ impact.
 
The patterns of injuries to the passengers will give clues to the crash, the speed of the aircraft and how the aircraft breaks up. A pathologist will plot severity and types of injury to passenger seating and build up a profile that will provide clues to reconstructing the crash.

In military accidents investigators need to be cautious as clothing of military personnel may contain ammunition or flares. The pathologist will also have to determine injuries caused by windblast and exposure when pilots eject from fighter planes.

Toxicology tests also play a key role in detecting carbon monoxide, alcohol and drugs, both recreational and less obvious over the counter drugs. Maidment outlined one investigation into a plane crash in the Alps that potentially saved many lives. It became apparent from toxicology tests that all passengers had died before the crash of carbon monoxide poisoning. Further examination of the plane’s debris revealed that a faulty heater had caused fumes to be released into the plane. The aviation authorities grounded all aircraft with the same model of heater and discovered similar defects developing that could have led to further accidents.

Histopathological examination may be undertaken and there may be testing for natural disease such as heart attacks or sudden conditions such as renal stones.

Wing Commander Graham Maidment gave an interesting insight into a specialised, important yet little-known role in that puts pathology at the heart of aviation safety. .

The AAPT conference in September 2007 saw a series of lectures on embalming, Inforce training for atrocity crime investigations; the Health Protection Agency and the chemical, biological and radiology project; tissue donation after death; training and education for anatomical pathology technologists; role of the consular officer; a Bosnian’s journey from working as an APT in Bosnia to Scotland; and finally, the roles and activities of the Federation for Healthcare Science. The conference also hosted a trade exhibition and a dinner.

Further information

UK Air Accidents Investigation Branch (AAIB)
www.aaib.dft.gov.uk

Role of Aviation Accident Pathology in Fatal Aircrash Investigation
AVM SK Adaval AVSM VSM (Retd)
http://www.isam-india.org/essays/cme_role.shtml

 Abstract
In addition to assisting the Coroner or Procurator Fiscal in fulfilling their duties to identify the deceased and arrive at a verdict as to how they have died, the pathological findings from the autopsy of the victims of a fatal aircraft accident provide an essential component of the overall investigation of the accident. The findings may assist in determining the cause of the accident, or may provide information on the survivability issues which may promote flight safety. The demonstration of natural disease, patterns of injury, toxicological findings and assessments of interaction with flying clothing, the aircraft controls or the flight environment may all contribute to the understanding of the accident and the prevention of similar deaths in the future. Close cooperation between the pathologist, the legal authorities and the air accident investigators is essential. Ideally, the autopsies should be performed or the finding reviewed by a pathologist with experience of aviation pathology.