China Eastern Crash: Experts explain what happens when a plane goes down

When an aircraft accident occurs, it triggers an immediate response from a complex set of role players across many disciplines.

One of the primary first efforts at a scene, after putting out blazes and looking for survivors, is to locate the cockpit voice recorder and the flight data recorders.

The answers to an air crash usually lie in these data capturing devices.

Watch aviation expert Shelley O’Connell from Readiness Squared and aviation engineer Sybrand Strachan explain what happens when a plane goes down as well as share some thoughts about the China Eastern air-crash.

The accident occurred on Monday 21 March when China Eastern flight MU5735, en route from Kunming to Ganzhou, Boeing 737-800 ploughed into a hillside at an almost vertical descent from 29 000 feet.

Last night Chinese Civil Aviation reported that it had found one of the devices, believed to be the cockpit voice recorder, battered but in relatively good internal shape.

There are some possible causes for the air-crash, said Strachan.

Bad weather has been ruled out by information from the Chinese weather service and flight plans.

Severe turbulence was also unlikely.

He said that a catastrophic structural failure or explosive decompression could have been causes, or, as in the case with a German Wings flight seven years ago, suicide.

Also Read: SA’s Boeing fleet safe and reliable

Strachan said video footage indicated that part of the tail, the horizontal stabilisers, were missing.

He said that could explain the rapid descent.

“The fuselage seemed to be intact, ruling out explosive decompression “

Reports also suggest that the aircraft slowed down somewhat before rapid descent. This could suggest that it also lost its wings, said Strachan. But he noted it is not clear on available visuals.

Cruising altitude for a Boeing 737-800 ranges between 29 000 and 39 000 feet above sea level.

The China Eastern flight bulleted to the ground from 29 000 feet in less than three minutes.

A pilot said to The Citizen that the real cause of the air-crash is anyone’s guess now and a thorough investigation of the aircraft’s technical records and logbooks would have to be initiated, along with what the flight data and cockpit voice recorder data reveals once available.

The pilot said that there are many variables but now all indications are that the empennage came off.

It’s aviation-speak for the whole tail section of the aircraft that includes both horizontal and vertical stabilisers, the elevator and the rudder.

While China Eastern grounded its entire fleet of 73-800’s in a cautionary move, aircraft engineer Sybrand Strachan and aviation safety expert Shelley O’Connell said that South Africans need not be concerned about their safety.

Many airlines in South Africa, including Comair and FlySafair, make use of the 737 series aircraft, including the 800.

FlySafair, who operates one of the largest fleets of the aircraft type in South Africa were quick to reassure travellers.

Its spokesperson Kirby Gordon said: “The Boeing 737 family of aircraft is one of the most popular and fastest selling family of aircraft in modern aviation. Millions of passengers worldwide have flown on these aircraft. In South Africa most carriers operate the 737-800 New Generation aircraft which has a phenomenal track record for safety and reliability.”