A look inside the Air Accidents Investigations Branch
The BBC has been given exclusive access to the work of the Air Accidents Investigations Branch (AAIB) in Farnborough.
Transport correspondent Paul Clifton met with crash investigators at the AAIB to see how they determine the cause of a number of air incidents.
His report comes weeks before the final publication of a report looking into the cause of a jet crash at the Shoreham air show last year, which killed 11 men.
Air experts said they investigate over 200 incidents and 20 deaths a year - with most involving light aircrafts.