Immediately after the plane crash in Iran, it was claimed to have been caused by pilot error or a technical fault. This was later downplayed. But there are many questions: the pilots were experienced and the plane – a Boeing 737-800 – was only 3.5 years old.

It's too early to draw. few conclusions, points out aviation safety expert Jan Ohlsson. He believes that there are many uncertainties and question marks regarding the plane crash.

”"The plane is a common model that has a very high reputation. There has never been a similar accident involving this machine, even though there are thousands in traffic. This increases suspicion about what the fault actually is," says Jan Ohlsson.

Hans Kjäll, also an aviation safety expert with a past including as an analyst at the then Swedish Civil Aviation Authority, agrees that the aircraft type is well-used and safe.

”"It is a proven aircraft type that is still under production. There is no shadow on the aircraft if it is maintained according to the rules. But we know nothing about that," says Hans Kjäll.

Ukraine embassy in Iran initially stated that the crash was caused by an engine failure – and not terrorism. But the embassy later denied that statement.

There is no known evidence yet that it was caused by an engine failure. Until the information in the found black boxes has been analyzed, it is not possible to say what caused the crash.

”"There are a number of open questions. Did the crew shout any distress calls to air traffic control? We don't know anything about that. They said 'technical fault', but that has to be based on something. You have to wait to be able to say whether it is a technical fault until you have examined the black boxes," says Hans Kjäll.

The two black boxes contain important information – one about the pilots' communication with each other and air traffic control, and the other about the settings on board the plane. When the crash is to be investigated using these, which country they are sent to becomes an important question.

Given the tense situation between the US and Iran, the accident investigation risks being difficult, says Jan Ohlsson.

”"A crash investigation should be conducted with representatives from manufacturers and engine manufacturers. This means that France and the United States, which manufactured the fuselage itself, should be present, but it is unlikely that an American would be sent to Iran right now, perhaps hardly a Frenchman."”

Hans Kjäll says that according to international accident investigation standards, a preliminary accident report should be issued within 30 days.

”"It only contains facts about what happened and what consequences it had. The answer to the question why must wait until the final report. Such an investigation takes at least six months, sometimes up to a year. It will be a long time before we find out what caused this," says Hans Kjäll.

Source: TT