What that means is that, although they know the aircraft was flying too low and too slow, and that the engine wasn't at full power when it should have been, they can only speculate as to why. The vintage 1955 Hawker Hunter crashed in a fireball on the busy road on August 22, 2015, smashing into vehicles and pedestrians and injuring 16 more people. Image copyright PA Image caption Pilot Andy Hill survived the crash

The parents of victim Matthew Grimstone, 23, said: "Apart from anything that the pilot may have got wrong it is very evident the Civil Aviation Authority (CAA) and the Shoreham Air Show organisers have got much to answer for. Rules laid down by the CAA were quite clearly inadequate and those that were there were, in some cases, not fully adhered to by the air show organisers.”

Mr Hill, from Sandon, Hertfordshire, suffered serious injuries. Organisers of the Shoreham Air Show said it was 'unlikely' they will ever stage 'the same or a similar' event again. • None The 1955 Hawker Hunter was going too slow during manoeuvre and 'failed to use maximum thrust'
• None The pilot 'could have pulled out of the stunt up to four seconds after reaching the top of the loop', but that Mr Hill 'did not perceive or realise it was necessary'
• None Mr Hill had 'not received formal training to escape the manoeuvre'
• None He may have been confused with a 'very similar' aircraft he had flown during the run up to the event
• None Mr Hill failed to answer questions in seven separate interviews about his 'conduct' during the flight due to 'doctors' restrictions'
• None The plane itself had 'not been properly maintained'

Responding to the AAIB report into the Shoreham air disaster, the parents of victim Matthew Grimstone, 23, said that the Civil Aviation Authority and the air show organisers 'have got much to answer for'. He was therefore able to describe his normal practice but not the events on the day of the crash. But Mr Hill began the stunt at 185ft and a speed of 310 knots, reaching 2,700ft at the top of the loop. 'A fireball headed towards us at 400mph'

Live updates: Shoreham air disaster report

On publication of the report into the disaster, AAIB principal inspector Julian Firth said: "The aircraft crashed because at the top of its aerobatic manoeuvre it was too low to complete it." The final report by the Air Accidents Investigation Branch (AAIB) stated that the speed the 1955 Hawker Hunter was doing when it entered the manoeuvre was too low, and it failed to use maximum thrust. Flight trials indicated the pilot could have pulled out of the stunt up to four seconds after the aircraft reached the top of the loop, but Mr Hill either did not perceive it was necessary or did not realise it was possible, the AAIB said. The report said: "The pilot had not received formal training to escape from the accident manoeuvre in a Hunter and had not had his competence to do so assessed. The speed, height and thrust followed in the Hunter were 'very similar' to another aircraft that the pilot had flown during displays in the run up to the Shoreham event, AAIB principal inspector Julian Firth said. He added that it was possible 'the pilot recalled the wrong numbers, essentially mixing up the two aircraft.' Image copyright PA Image caption Eleven men were killed and a further 13 people, including the pilot, were injured

The AAIB also found the severity of the outcome of the crash was due to "an absence of provisions to mitigate the effects of an aircraft crashing in an area outside the control of the organisers of the flying display". Mr Hill, 52, from Sandon, Hertfordshire, survived the impact despite suffering serious injuries and is being investigated by Sussex Police for possible manslaughter. He was interviewed on seven occasions by AAIB investigators but because of restrictions advised by his doctors they were not able to question him about his conduct during the flight, the AAIB said. Safety measures at all UK civil air shows were enhanced following the disaster and the CAA said it had reviewed every aspect of air display safety.
The Air Accidents Investigation Branch determines that a pilot error was the cause of the crash.