Pilots of doomed Chinese plane that crashed did not respond to calls

Agencies | Beijing

The Daily Tribune – www.newsofbahrain.com

The pilots of the doomed China Eastern Airlines flight failed to respond to calls from air-traffic controllers after tipping into a deadly nosedive. The jet was traveling at close to the speed of sound just before it slammed into a hillside, according to a Bloomberg News review of data. Such an impact may complicate investigators' task because it can obliterate evidence and even damage data recorders designed to withstand most crashes.

The black boxes from Flight 5735 haven’t been recovered. Rough terrain and the state of the aircraft, which plunged from about 29,000 feet (8,840 meters), make the search difficult.

The Boeing Co. 737-800 was knifing through the air at more than 640 miles per hour, and at times may have exceeded 700 mph, according to data from Flightradar24.

"The preliminary data indicate it was near the speed of sound," said John Hansman, a Massachusetts Institute of Technology astronautics and aeronautics professor who reviewed Bloomberg’s calculation of the jet’s speed. "It was coming down steep."

Sound travels at 761 mph at sea level but slows with altitude as air temperature goes down and is about 663 mph at 35,000 feet.

Investigators have offered no major insights as to why the jet carrying 132 people crashed near Wuzhou in southern China on Monday, saying at a press conference late Tuesday it was too early draw clear conclusions about the cause.

All 123 passengers and nine crew are presumed dead.

China Eastern grounded its fleet of 737-800s and thousands of domestic flights were cancelled Tuesday across the nation. Officials have ordered a sweeping two-week safety review.

What happened to China Eastern Airline flight MU5735?

Flight MU5735 was travelling from Kunming to Guangzhou when it plunged from cruising altitude. The jetliner was cruising at about 595 mph before the dive.

> At 9:20 am (Bahrain time) the plane was cruising at 29,100 feet.

> 135 seconds later it nosedived to 9,075 feet.

> 20 seconds later it was just 3,225 feet above the ground.

The plane plunged almost 26,000 feet in 95 seconds.

The speed data is consistent with videos appearing to show the jet diving at a steep angle moments before impact and indicates it hit the ground at force.

Aviation experts are at a loss to explain the events. 

"It’s an odd profile," John Cox, an aviation safety consultant and former Boeing 737 pilot, said, "It’s hard to get the airplane to do this."

The probe will try to determine why the plane made such an abrupt and severe dive, which sets it apart from earlier accidents. 

Among other points, aviation experts will consider weather conditions and examine wreckage for any signs of possible malfunction.

Once the data recorders - which also logs conversations between pilots - are found, they will also see if distress calls were made.