The disappearance of Malaysia Airlines 370 recalls another state-of-the-art aircraft that went missing over open water: Air France Flight 447, which plunged into the Mid-Atlantic in 2009 and resulted in the deaths of 228 people.
Like the Malaysian jet, a Boeing 777-200, Air France's Airbus 330 was a sophisticated aircraft that wasn’t supposed to suddenly vanish without word from the crew.
“This was a modern, latest generation airplane which has gone missing,” David Learmount, operations and safety editor at Flight International magazine, told NBC News. "These don’t just fall out of the sky. Modern airplanes just don’t.”
A French report that took several years to produce concluded that both technical and human error was behind Air France 447's final flight on June 1, 2009.
It found that external speed sensors, known as pitot tubes, on the outside of the Airbus iced over and caused the automatic pilot to disengage. This left the pilots without essential information, the report found.
A junior pilot then took control manually.
The flight’s “stall alarm” then went off after the pilot pulled up the airplane’s nose in an attempt to stabilize the aircraft. Standard guidance in those sorts of situations is for the pilot to lower the plane’s nose, experts say.
A stall is when a plane stops flying and starts falling.
"The pilots must either have stopped believing what they were seeing, or if they did give it any credence, their minds were rejecting the horrific implications."
The plane’s engines, meanwhile, continued to run at full speed.
With its nose up 15 degrees, the plane was at the wrong angle to recapture lift and become buoyant. The aircraft then plunged into the ocean at a rate of about 10,000-feet-per-minute.
"The report does not say it explicitly, but the pilots must either have stopped believing what they were seeing, or if they did give it any credence, their minds were rejecting the horrific implications of this combination of nose-high attitude, rapid rate of descent, and high power," Learmount wrote in a detailed article on the accident.
So junior pilots — acting while the captain was on a short break — did not know how to respond to the malfunctioning equipment and were also to blame for the tragedy, according to the report and experts.
Although the 58-year-old captain returned from a break about a minute into the four-minute emergency, he was not at the controls when the plane crashed into the water, information from the black boxes showed.
Gerard Feldzer, former airline pilot and flight instructor, told France 24 when the report was released that it was important for pilots to be taught to deal with “exceptional circumstances.”
For example, the stalling alarm likely threw off the pilots, who had never been trained to deal with that sort of situation. That seemed evident given that the plane was simply not supposed to stall, Feldzer said.
Pilot training has changed since the accident, he added.
“We’re training them to be all-rounders and not be limited to a specific curriculum,” Feldzer said.
NBC News' Duncan Golestani and Reuters contributed to this report.
