Emirate Airlines boss Sir Tim Clark knows that the sudden disappearance of the Malaysian Airlines MH370 is still a big mystery, but he is quite convinced that the plane might night be in Indian Ocean after all.

Clark said in an interview with German newspaper Der Spiegel that authorities should be more analytical in investigating the incident, saying that their initial theory might be wrong because they have not found any trade of the missing plane.

"Every single second of that flight needs to be examined up until it, theoretically, ended up in the Indian Ocean - for which they still haven't found a trace, not even a seat cushion," Clark said of the missing plane, which went missing on March 8 with 239 passengers and crew on board.

Clark is also convinced that the Malaysian Airlines MH370 was not on autopilot before it came down, contrary to previous speculation that the pilot was not in control of the plane hours before it allegedly crashed.

"Our experience tells us that in water incidents, where the aircraft has gone down, there is always something," Clark stressed. "We have not seen a single thing that suggests categorically that this aircraft is where they say it is, apart from this so-called electronic satellite 'handshake', which I question as well."

Clark, whose company operates 127 Boeing 777 planes like the missing MH370 plane, is wondering how it became possible that no one in the company seems to have a concrete idea about the fate of the missing airplane. He said that investigations should continue, but he appealed that the authorities should be more transparent.

"MH370 has simply disappeared. For me, that raises a degree of suspicion," Clark said. "I'm totally dissatisfied with what has been coming out of all of this. There is plenty of information out there, which we need to be far more forthright, transparent and candid about."

Clark is hoping that the incident will not remain as a mystery, expressing fear that the involved parties will just move one and just let the disappearance be treated as one of the greatest aviation mysteries.

"I have the concern that we will treat it as such and move on," Clark added. "At the most, it might then make an appearance on National Geographic as one of aviation's great mysteries. We mustn't allow this to happen. We must know what caused that airplane to disappear."