Deliberate action?

After analyzing data exchanged between the plane and a satellite, Australian officials said on June 26 that Malaysia Airlines Flight MH370 was "highly likely" to have been on autopilot when it went down. Moreover, after comparing the conditions on the flight with previous disasters, the authorities issued a report stating that those on board the missing plane most likely died from suffocation and coasted lifelessly into the ocean on autopilot. The officials, however, failed to explain why the autopilot would have been set on a flight path so far off course from the jet's destination of Beijing.

The fate of Flight MH370 has been shrouded in mystery ever since the passenger jet left Kuala Lumpur for Beijing in the early morning hours of March 8 with 239 people on board. While the Boeing 777 is believed to have crashed in the southern Indian Ocean, international search efforts have so far failed to provide any clues as to what happened to the plane. This is why investigators have decided to shift the search south along a narrow arc identified as the most likely resting place of the jet.

In a DW interview, Hamburg-based aviation expert Heinrich Grossbongardt says he can't imagine any technical problem which would kill all communication systems of an airplane and prevent the pilots from controlling the aircraft, while leaving autopilot, attitude control, fuel pumps and other vital systems intact.

DW: Is the straight path the plane reportedly flew an indication that the jet was flying on autopilot?

Heinrich Grossbongardt: Flying on autopilot is the normal operating mode when an aircraft is en route. Changes in altitude or direction are done via selector switches, which are located above the instrument displays. Flying a big jet for hours on a constant course at a constant altitude manually simply makes no sense.

What does it take to switch a plane to autopilot?

There is a rotary switch where pilots select various autopilot modes.

Could a person without any knowledge of aviation do this?

You only need little knowledge to do this, but it is very unlikely that this could have happened by accident due to the several changes in direction the aircraft made.

If, as the authorities suggest, the autopilot was still working when the plane crashed, what does this suggest to you?

I can't imagine any technical problem - be it fire or malfunction of avionic systems - that would kill all communication systems and prevent the pilots from controlling the aircraft, while leaving autopilot, attitude control, fuel pumps and other vital systems intact plus degrading ACARS just to the point that it still responds to satellite pings, but does not transmit any data.

Would you see this as a further indication that the airplane lost communication and identification with air traffic control because the systems were turned off deliberately?

Absolutely. I don't see any other scenario that would explain the pattern we know today.

Given the latest developments, does the focus of attention remain on the pilots?

Yes. A suspicion like this always causes additional grief for the families who just lost a loved one. But currently it is the scenario that, in my opinion, makes the most sense.

The search area has changed multiple times in the months since MH370 vanished. What are the chances of investigators finding the plane in such a vast area?

As there is no time pressure anymore they will now follow a very systematic approach and search the seafloor with towed sonar systems. If they don't find the aircraft on the first run, the sonar data will be analyzed carefully in order to narrow down the search to areas of special interest.

This might take months or even years as the search operation will pause during the storm season and will resume when the weather is more favorable. I am quite confident that this approach will eventually yield success.

Heinrich Grossbongardt is an independent aviation expert and managing director of Expairtise, a Hamburg-based communications agency specializing in aviation and aerospace.