At least 11 people were killed when a Hawker Hunter jet crashed on to the A27 during a display at the Shoreham Airshow.
Aviation regulator the Civil Aviation Authority (CAA) has said it is considering whether safety requirements should change as a result of what happened at Shoreham, one of the worst air show accidents in recent years.
The Shoreham Airshow takes place annually at Shoreham Airport in West Sussex and is run by the Royal Air Force Association (RAFA).
Some 50 aircraft, including many classic jets, were scheduled to take to the skies for display flights during the two-day event. Among them was a vintage Hawker Hunter jet, flown by pilot Andy Hill.
Eyewitnesses say the plane had just begun its flight and was performing a loop when it failed to pull out of the manoeuvre and crashed into traffic on a busy main road, the A27, at about 13:20 BST.
Footage captured by spectators at the airshow and nearby motorists showed a large fireball engulf the area.
A major incident was declared, with one of the paramedics describing it as a scene of “utter devastation”.
What might have caused it?
It is not yet clear what caused the crash, but eyewitnesses said the aircraft appeared to come out of the loop manoeuvre “too low”.
Shoreham resident Dave Penwarden, 51, saw the plane explode. “It just didn’t seem to have enough speed to come out of the loop, instead of powering out it dropped too fast and hit the ground.”
Pilot Darren Sharp, who was a spectator at the event, told the BBC he believed the pilot had realised he was in trouble and made a “brave decision” to take the plane down away from the airfield where thousands of people were standing.
Friend and fellow pilot Neil McCarthy said he believed Mr Hill had “the experience to roll out of the manoeuvre at the top and not complete it” if he lacked enough height.
“The height looked high enough to me,” he said. “But so many things can go wrong, there can be bird strikes, engine failure, an engine fire, there could be all sorts.”
What do we know about the plane?
The Hawker Hunter was a mainstay of the RAF through the 1950s and early 1960s. First flown in 1951, the single-seat plane was used as a fighter-bomber for reconnaissance and for aerobatics.
There was also a two-seat trainer version, which served with many other air forces. Two-seater variants are still used by the RAF for training.
Neil McCarthy said the precise type of aircraft was a 1950s Hawker Honda, of which there were “probably only five flying at the minute”, with Mr Hill one of only about six pilots who could fly it.
The RAFA says all air display arrangements, including the pilots and aircraft, must meet rigorous Civil Aviation Authority safety requirements and are regularly reviewed to ensure they provide the highest possible levels of protection.
Who is the pilot?
Andy Hill, 51, from Sandon, near Buntingford in Hertfordshire, is a former RAF instructor and British Airways pilot. He is also an experienced aerobatic stunt flyer who has performed at shows up and down the country.
He was not originally meant to pilot the plane. Another former RAF pilot Chris Heames was originally listed in the air show’s programme, and it was only decided last month that Mr Hill would fly the aircraft instead.
Mr Hill was pulled from the burning wreckage, and is in a critical condition in hospital. He has multiple injuries and is in a medically-induced coma.
His family said they were devastated and deeply saddened for the loss of life, and sent condolences to the families of those affected.
George Bacon, of the British Air Display Association, who had worked with Mr Hill described him as “unbelievably experienced” and his preparation for air displays as “second to none”.
Who are the victims?
At least 11 people died and a further 14 people were injured, four of whom were taken to hospital. Police said the death toll could continue to rise as the recovery operation progressed.
Sussex Police said the crash site is spread over about 400 yards of the A27 and extends to the adjoining airfield. All of those who died are thought to have been on the road.
Among them was Matt Jones, 24, a personal trainer, named by his sister Becky Jones on Facebook as one of the dead.
Two Worthing United footballers and schoolfriends Jacob Schilt, 23, and Matthew Grimstone, 23, thought to have been travelling together, were also named as victims.
Is there a problem with air show safety?
According to the RAFA, the UK has among the most stringent safety requirements for air displays in the world, with both pilots and aircraft undergoing numerous checks. It said it took safety arrangements “very seriously”.
Dozens of air shows take place across the UK every year, with the overwhelming majority passing without incident.
However there have been a number of incidents at air shows over the last decade, including some which led to fatalities – mainly to pilots. It is also the second incident at the Shoreham Airshow in recent years.
In September 2007 James Bond stuntman Brian Brown, 49, died when he crashed a World War Two Hurricane after carrying out an unplanned barrel roll at a re-enactment of the Battle of Britain. A report recommended the sequence of manoeuvres should be clearly specified in advance of flying displays.
Following the latest disaster, the family of one of the victims has called for acrobatic air displays to be held over sea rather than land to minimise the potential for fatalities.
The Civil Aviation Authority has said it is looking at whether air show safety requirements should change.
Who will investigate?
The Air Accident Investigation Bureau (AAIB), which investigates civil aircraft accidents and serious incidents within the UK, attended the scene of the crash.
A team will continue to investigate as the recovery operation progresses. The operation to remove the wreckage of the plane began on Monday.
Their investigation will eventually conclude with a report analysing the circumstances and possible causes of the incident, without attributing blame, as well as offering possible recommendations about how aviation safety might be improved as a result.
The AAIB has asked anyone who has video or photographs of the plane in the time leading up to and including the crash to keep hold of them and await advice as to whether they may be wanted to assist with the investigation.
The British Aviation Display Association and the CAA have both said they will look at what lessons might need to be learned.