Friends and family are praying for a Brisbane pilot after the light plane he built himself crashed at a Sunshine Coast airport, leaving him with multiple serious injuries.
Amateur pilot Ben Berg underwent urgent surgery on Saturday night, hours after his four-seater plane flipped and crashed on landing at Caloundra Airport.
Close friend and flying buddy Errol van Rensburg said the 49-year-old electrical engineer was badly injured but had stabilised after surgery.
Mr Berg's South African-designed Sling 4 piston-engine kit plane plane stalled on landing at Caloundra Airport about 11.45am on Saturday, flipping and crashing into bushes, according to emergency services.
He was trapped for more than an hour as a swarm of people worked frantically to free him and one of his passengers, who spent about half-an-hour confined inside.
The South African-born pilot was airlifted to the Royal Brisbane and Women's Hospital in a critical condition with multiple injuries to his head, chest and legs.
On Saturday evening, his wife Lana van den Berg and anxious friends and family were waiting by Mr Berg's bedside as he went through surgery.
"It's really always bad news when it's a plane crash, especially when it's a close friend," Mr van Rensburg said.
"He's stable but obviously in a very serious condition so you know time will tell but it was a bad crash I think.
"... I think it's going to be a long road to recovery."
The other trapped man was taken to the Sunshine Coast University Hospital in a serious condition, along with a man and a woman who were treated for minor injuries.
Mr Berg built the 2015-registered plane himself over about two years.
Mr van Rensburg, the Australian distributor for the Sling craft, said his friend's build was one of the better and most meticulous and examples of craftsmanship he had seen.
"What happened there, it's sort of mind-boggling," he said.
"Because he's already flown, I would say, probably about 50 hours in it since he's constructed it."
According to Mr van Rensburg, his friend and his wife had taken off from the Jacobs Well Airfield on the northern Gold Coast on Saturday morning, headed to Caloundra.
They arrived safely and met some friends, who Mr Berg decided to take on a joyride before, which was when the accident took place, the fellow South African said
Mr Berg had been testing out his "pride and his joy" just last month, flying high over the Gold Coast with the ocean on his right and Surfers Paradise to his left.
But something went wrong on Saturday as the Sling 4 stalled on landing and crashed into bushes at the Caloundra Airport.
"Fire and rescue crews initially laid a layer of foam over the area due to the amount of … gas that had leaked from the aircraft," Queensland Fire and Emergency Service officer Kent Mayne told reporters on the Sunshine Coast.
"We had six fire and rescue officers there. One special team rescue … and the guys along with the QAS paramedics who did a really good job."
Mike Smith, President of the Gold Coast Sports Flying Club based at the airfield, confirmed the pilot was part of his club but said he had no idea what went wrong.
"They are an excellent aircraft," he said, of the Sling planes.
The Australian Transport Safety Bureau was informed of the crash but did not send an investigator.
A spokesman said the organisation would decide on Monday whether to investigate further.