Eleven men died when a vintage Hawker Hunter aircraft crashed at the Shoreham Airshow in August 2015.
As an investigation has concluded that pilot error caused the disaster, Sky News takes a look at the man who was behind the controls of the jet.
:: Flying career
Andy Hill, from Sandon, Hertfordshire, received flying training with the RAF and served as an instructor and fast jet pilot before going into commercial aviation.
Between May 2011 and August 2015, the 52-year-old flew the Hawker Hunter for a total of 40 hours - including almost 10 hours in the 90 days before the crash.
He held a European Union Airline Transport Pilot's Licence and was authorised by the Civil Aviation Authority to fly the Hawker Hunter in displays.
Mr Hill had also flown at air displays in other types of aircraft. He was issued with a medical certificate in January 2015, which was valid for 12 months.
:: Shoreham disaster
Mr Hill was thrown clear from the plane during the crash and was taken to hospital in a critical condition.
After coming out of a medically induced coma he recovered and was discharged from hospital the following month.
Following the crash, George Bacon of the British Air Display Association said Mr Hill was "an unbelievably experienced chap" who was "very thorough and professional" in his preparation.
Neil McCarthy, who has flown similar Hawker Hunter aircraft, described Mr Hill as a "very accomplished" pilot.
He told Sky News: "(Mr Hill) is an expert at what he does and a very, very safe pilot.
"It's not dangerous, it's a calculated risk. We're flying fast jets at low level but when you get to the kind of level Andy is at these are not issues."
Despite this, fast jet pilot Chris Heames told Sky News "there are risks involved" in air show displays.
An incident involving Mr Hill at the 2014 Southport Airshow has formed part of Sussex Police's probe into the Shoreham air crash.
It was said the jet the pilot flew in Southport was considered to be low.
Witness Stephen Lomax said visitors were worried about "how close" the jet got to them.
In March 2016, an interim report by the Air Accidents Investigation Branch (AAIB) found that Shoreham Airshow organisers were unaware of Mr Hill's display plans before his jet crashed.
It added that a risk assessment carried out in advance of the event did not "show the range of hazards presented by different display aircraft".
Sussex Police later confirmed Mr Hill is being investigated for possible endangerment pursuant to Article 138 of the Air Navigation Order 2009 and also manslaughter by gross negligence.
He has been questioned voluntarily under caution by police.
In September, investigators won the right to see film footage from within the place before the crash.
However, Sussex Police was denied the chance to see copies of reports on human factors, engineering, tests and speed calculations, as well as records of interviews with Mr Hill.