A former Qantas pilot has outlined a terrifying chain of events that may have sent a private jet plunging towards the ground at 30,000 feet per minute, killing all nine people on board.

The Learjet 60 was travelling from Austin, Texas, to the Bahamas when it crashed into a residential area in Palm Beach County, Florida, on Sunday.

WATCH THE VIDEO ABOVE: Private jet crashes in Florida killing nine

Footage captured the aircraft’s final moments as it hurtled towards the ground, narrowly missing nearby homes and vehicles before exploding on impact.

Speaking on Sunrise on Tuesday, Richard de Crespigny said he believes the aircraft may have encountered a powerful thunderstorm, with violent updrafts and ice potentially triggering a catastrophic failure of its stabiliser.

He said information transmitted from the aircraft suggested it had lost the ability to maintain its cruising altitude before entering a rapid descent.

The possible chain of events

The aircraft’s crew had reported turbulence and icing conditions to air traffic control shortly before the emergency escalated.

De Crespigny said the conditions could have become particularly dangerous if the Learjet had encountered a powerful thunderstorm.

He suggested the aircraft may have initially been pushed upwards by powerful air currents before ice accumulation affected its ability to maintain control.

“We have warm water from the Gulf Stream percolating up in dry, cold air in a thunderstorm that can grow in 10,000 feet in one minute,” he said.

Severe turbulence can pose significant risks to aircraft, particularly when associated with powerful thunderstorms.

The aircraft also had a known icing problem involving its stabiliser, according to de Crespigny.

“If that lost the ability to hold the nose up, the aircraft speeds up, perhaps the tailplane or the stabiliser breaks off and then they go into a 600 kilometre vertical dive,” he said.

He said a failure of the stabiliser could have left the pilots unable to keep the nose of the aircraft elevated.

“Maybe it entered an updraft from a thunderstorm, and then there were two different rates of descent consistent with perhaps a slow loss of control, perhaps by a stabiliser being ripped off the aeroplane,” he said.

“They can’t hold the nose up. They go into a ground almost like a missile.”

However, de Crespigny stressed the explanation remained a theory, with investigators yet to determine whether the aircraft suffered a mechanical failure.

The risks of private flying

The former Qantas pilot said the incident highlighted the significant safety differences between commercial aviation and private flying.

“I think people need to realise that commercial aviation is about five times safer,” he said.

“In other words, the charter market has about five times the number of accidents and private flying at least 10 times.”

He said aircrafts were designed to withstand significant forces, but the updrafts associated with thunderstorms could still pose a serious threat.

What investigators are looking for

The US National Transportation Safety Board (NTSB) is leading the investigation, examining the wreckage, flight data and weather conditions at the time of the crash.

De Crespigny said investigators would need to establish whether the aircraft lost its horizontal stabiliser and whether the pilots had been able to identify the approaching storm.

He warned locating the flight data recorder could prove difficult, with the device only certified to withstand forces of up to 3000G, potentially insufficient to survive the impact.

He said investigators would also examine whether the aircraft’s radar had detected the storm and why the jet may have flown into it.

The NTSB has separately flagged evidence that the aircraft may have broken apart before impact, although no cause has been established.

De Crespigny cautioned against drawing conclusions before the investigation was complete.