Tuesday, 24 January 2017

Why Doors In The Planes Are Closed When A Flight Is On Air


It is a scenario out straight out of your worst nightmares.

Imagine you are on a plane, flying 35,000 feet in the air and suddenly someone opens the exit door.

Images of people being sucked out of the cabin come to mind, but what would really happen?

Firstly, the cabin would lose pressure rapidly and anyone standing near the exit would be sucked out into the sky.

The temperature would plummet to below-freezing and the plane may begin to break apart.

Like what happened in 1988 to a Boeing 737 flight heading to Honolulu which encountered a roof rupture at 24,000 feet with 90 people on board.

The decompression tore off a larger section of the roof and 57-year-old flight attendant Clarabelle Lansing was swept from her seat and out of the hole.

Luckily, no one else died as all passengers were belted up and the pilot managed to land 13 minutes later.

The more common slow decompression can be fatal. There are around 40 to 50 instances of this per year, where the cabin loses pressure very slowly due to a fault.

One of the more notable instances was in 2005 when another Boeing 737 became the most fatal air disaster in Greek history killing all 121 passengers and crew due to gradual loss of cabin pressure.

This was due to an error in the pressure system state where it was set to manual instead of auto. It was just 13 minutes after takeoff that ground staff lost contact with the crew. The lack of oxygen left the crew incapacitated and suffering hypoxia – dimmed visions, slow thinking, unconsciousness and, ultimately, death.

The plane, on auto pilot, flew until it ran out of fuel and then crashed.

However, while this instance was a result of overlooking the pressure system state, opening a plane door mid-flight is actually impossible.

“Cabin pressure won’t allow it,” pilot and author of Cockpit Confidential Patrick Smith told the Telegraph.

“Think of an aircraft door as a drain plug, fixed in place by the interior pressure. Almost all aircraft exits open inward. Some retract upward into the ceiling; others swing outward; but they open inward first.”

“At a typical cruising altitude, up to eight pounds of pressure are pushing against every square inch of interior fuselage. That’s over 1,100 pounds against each square foot of door.”

The only known incident of a plane door being opened by a passenger mid-flight was in 1971 when a man hijacked a Boeing 727, demanded a £160,000 ransom and then let from the exit and was never seen again.

However to be able to open the cabin door he had the pilot depressurise the plane. A year later “Cooper vanes” were installed to completely disable aircraft doors mid-flight.



Etiam at libero iaculis, mollis justo non, blandit augue. Vestibulum sit amet sodales est, a lacinia ex. Suspendisse vel enim sagittis, volutpat sem eget, condimentum sem.