"Everything points to the fact that it was suicide. That one of the pilots deliberately cut off the fuel supply at the exact moment when the plane was most sensitive, right after takeoff," Grosbongart told "Spiegel".

Indian investigators have published a preliminary report on the accident,"Welt" reports.

According to the report, one pilot asked the other why he had shut off the fuel supply. The other replied that he did not.

Not long after, the engines lost power and the plane began to rapidly lose altitude.

Shortly thereafter, the fuel supply switches were turned back on. Although the engines partially regained power, one of the pilots had already sent out a call for help.

When the control tower asked what was happening, there was no more response. The flight controllers saw the plane falling and immediately alerted the emergency services. A technical error is considered highly improbable.

A preliminary report states that, seconds after takeoff, the two fuel controls for both engines were moved from the"run" position to the "off" position one after the other, one second apart.

Humanly speaking, only one of the two pilots in the cockpit could do that. Which of the pilots was able to turn off the regulators is still unknown.

Grosbongart thinks that inadvertent tripping of the regulator is ruled out as a possibility.

An Air India plane crashed on June 12 shortly after takeoff, landing in a residential area in Ahmedabad. Of the 242 people who were on the plane, only one survived.

According to the airline, 169 passengers were from India, 53 from Great Britain, seven from Portugal and one from Canada.

According to officials, another 19 people died on the ground. Air India said after the accident that the plane was well maintained and that both pilots had extensive flying experience.