Reason man was able to terrifyingly open plane door mid-air

An aviation expert explains how a passenger was able to open the door of a plane mid-air and yet no one died.

An aviation expert has revealed how a man was able to open a plane door sending air blasting through the cabin, forcing terrified passengers to grip their seats.

An Asiana Airlines flight was approaching Daegu International Airport in South Korea on Friday, local time with about 200 passengers onboard when the man opened the exit door at about 200m because he was feeling claustrophobic.

Chrystal Zhang, an associate professor of aerospace engineering and aviation at RMIT University, told news.com.au it was lucky there were no deaths or serious injuries.

But travellers may be relieved to know, the dangerous act is not actually possible while an aircraft is cruising in the sky – making this an “exceptional case”.

Dr Zhang explained that due to the difference in pressure from inside the cabin to outside the aircraft during a flight, there is “absolutely no way” passengers and crew could open a door.

“In this special case the aircraft is descending and it’s almost – only just one or two minutes – from touching the runway,” she said.

“So in that circumstance it is possible for anyone strong enough to force the emergency door open.”

The door was manually opened by a passenger about 200m above the ground. Picture: Yonhap/AFP

A video from inside the plane showed passengers gripping on to their seats. Picture: Twitter/rainboymach1

Dr Zhang said it was fortunate all the passengers had their seatbelts securely fastened.

There were no deaths or injuries on-board but about a dozen passengers understood to have breathing difficulties were taken to hospital.

“Some passengers really suffered from breathing problems and I think that’s really because of the strong wind and pressure – still a difference between inside and outside,” Dr Zhang said.

“And the speed, because when the aircraft was landing, the speed is still very very fast.”

She said it was lucky there were no casualties as there was potential for worse consequences if other passengers had existing heart problems or other health problems.

The man who opened the door said he felt suffocated. Picture: Yonhap/AFP

According to Yonhap News Agency in South Korea, the 33-year-old man had been sitting in the emergency exit row when he opened the door.

In response to the incident, Asiana Airlines and its budget carrier Air Seoul stopped selling certain emergency exit row seats.

Dr Zhang assumed this would be a precaution measure to make it harder for passengers to have access to the doors.

She believes there needs to be more serious conversations in the industry about screening passengers for exit rows now that flying is much more accessible to people compared to many years ago.

“Usually these days airlines charge people if they want to choose that particular row because you have bigger leg room,” she added as one example of current operations that may compromise safety.

The man who opened the door, with the surname Lee, told police he had wanted to get out of the plane because he was feeling “suffocated” inside the cabin.

“I wanted to get off quickly,” he told reporters.

“I’m very sorry to the kids,” Mr Lee added, referring to at least 48 school students who were on board.

Authorities said he also had been under stress from being unemployed.