MH370: Nine things we'll probably never know

Relatives of Chinese passengers aboard MH370 voice their anger at Malaysia Airlines. Photo / AP

Malaysian officials have confirmed that although the search for missing flight MH370 will continue, the disappearance of the aircraft has been labelled an "accident", in effect drawing a line in the sand over speculation.

But for those fascinated by the mysterious disappearance of the plane, which last made contact with air traffic control on March 8 2014, this means that there are many things we will - probably - never know.

1. Where is the plane now?

Obviously, this is the million-pound question. And one which Malaysian authorities have seemingly admitted they may never find. Although they had stressed that searching for the missing aircraft will remain a "top priority" - approaching a year after the plane's disappearance, hope is fading.

The most recent searches have focused on a swath of ocean off the western coast of Australia. Despite the use of sophisticated sonar equipment, and aid from governments including China, nothing conclusive has turned up.

2. Why were the plane's communications systems disabled?

MH370's transponder, which communicates with the ground, was shut down as the plane travelled from Malaysian air traffic control to Vietnamese controlled airspace.

There does not appear to be any rational explanation for this, with some aviation experts labelling the pilot's decision to do so "extraordinary". Fingers have been pointed towards malicious intent, either on the behalf of the pilots or of an unknown 'outside' player in the scenario.

Realistically, it is impossible to know and with the continued absence of the plane's black box we will probably never know the final moments in the cockpit.

3. Why was the plane's disappearance not spotted immediately?

As mentioned, the plane's was shut down during the flight, but this appears to have gone unnoticed until much later.

One possible reason for this is simply human error - Malaysian air control would have handed over to their Vietnamese counterparts and simply forgotten about it.

4. Why did the plane make a sharp left turn?

Conspiracy theories abound on this question. Military logs show the plane turned west, deviating from its planned flight path, shortly after the plane's transponder had been switched off and the last ACARS (the system used to communicate with the ground) datalink transmission had been sent.

One theory, suggested by aviation blogger Chris Goodfellow, claims that the sharp left turn came after the aircraft's communications were knocked out in some kind of catastrophe.

According to Mr Goodfellow, the actions of the pilot - in the situation - would be to turn towards the nearest safe airport, possibly Paulau Langwaki.

5. Was the plane hijacked?

Since 9/11 all alirlines hav fitted their cabin cockpits with reinforced 'bulletproof' doors designed to prevent exactly such a hijacking. Realistically, it is unlikely anyone would be able to get into the cockpit once these doors had been closed - moreover the pilots should have been able to issue a distress call had it happened.

There are times when the doors are open, which allows for the possibility of a hijack, or even if passengers had been invited into the cockpit - as the co-pilot of MH370 was shown to have done previously.

6. Did the pilots have something to do with the possible crash?

Extensive searches were carried out on both pilots' homes and backgrounds - and turned up nothing conclusive. But there is equally nothing to disprove it.

There have been occasions when pilots are believed to have carried out suicidal thoughts: Egypt Air flight 990 (1999) and Silk Air flight 185 (1997) are both considered to be examples of this.

7. Was the entire event just a series of fluke chances and bad luck?

We love a good conspiracy but there is a chance that the flight disappearance is the result of a series of accidents, disabling parts of the plane in stages.

For example; a fire could have caused the communications to be knocked out but left the plane broadly intact. Later, there could have been gradual decompression which would have caused hypoxia, incapacitating the crew and passengers, until the crash.

8. Would passengers have known something was happening?

It depends on what happened previously. If the events leading up to the plane's crash were hostile, then it is fair to expect that many passengers were aware that something was wrong.

However, given the time the plane appears to have disappeared - middle of the night - there is a chance many passengers would have been asleep and would have been unaware of the events unfolding around them, especially if the possible crash was just a fluke series of accidents.

9. Did the plane crash land?

It has been estimated that the plane still had enough fuel to fly another 2,200 miles from its known location after its communication devices were turned off. This leaves a dizzyingly large area - and roughly 634 runways where it is possible for an aircraft of that size could have landed.

Other suggestions - mostly from that most verifiable of sources "the Internet" - claim the flight could have landed on a deserted island somewhere. This plays into conspiracy theories suggesting the flight was hijacked and later touched down somewhere.

- The Independent