In March 2014, one of the most mysterious, confusing and tragic disappearances in history took place. A commercial flight with 239 people on board simply vanished, leaving behind a myriad of questions.

Many years on, it still isn’t known what happened to the flight. This is despite the most expensive and extensive search in aviation history having taken place.

In this article, we review 5 possible theories of what might have happened. We also have a poll at the end of the article which you can cast a vote on – asking you which theory is most likely.

Aviation tragedies are fortunately very rare


Malaysia Airlines Flight 370 (MH370) left Kuala Lumpur International Airport, Malaysia, bound for Beijing Capital International Airport, China.

The flight left on 8th March 2014, with pilot Zaharie Ahmad Shah at the helm of a aircraft that had a proven track record of safety. At first, the flight appeared to just be your average flight – those this soon changed.

Less than an hour following takeoff, the aircraft made its final voice contact to air controllers. Just three minutes later, the aircraft disappeared from radar screens. While it did remain on military radars for a further hour, this only resulted in further confusion.

MH370 veered significantly westwards back towards Malaysia – and well off course. While the flight was over the Andaman Sea – still way off course – it disappeared from military radars. No one ever heard from MH370 again. Pings received hours later suggested that the plane flew on for hours after contact had been lost.

The circumstances behind the disappearance are bizarre. There had been no distress signal, poor weather or technical problems. The fact that the aircraft also lost communication has led to speculation that they were turned off manually. A range of other potential theories followed too.

Over the next few months and years, searches went on. 46,000 square miles of the sea floor was searched, with nothing extensive found. The only true development came in July 2015, when a few debris of what was believed to be MH370 washed up on the shore of the Island of Reunion, off the coast of Africa. Furthermore, the nation of Tanzania also had some debris wash up.

As this is the only concrete finding, a range of theories have been put forward to explain what might have happened. We now take a look at the various theories put forward.

Theory 1: Unresponsive Crew

Explained: This theory suggests that the crew, and possibly pilots too, were rendered unconscious during the flight. This could be explained by an oxygen deficiency. It is likely that the aircraft would’ve remained on autopilot, before crashing into the sea once fuel ran out.

For: This is a very logical explanation. As it is known that the plane flew for hours after communication was lost, this would tie in with this theory – with the aircraft essentially becoming a “ghost” flight. It would also explain how the aircraft ended up in the sea – which appears to have happened. It would also explain why a distress call wouldn’t have been made, as they would have probably become unresponsive quickly.

Against: The biggest question mark over this theory lies with the fact that it doesn’t give an explanation for communications being lost. There is simply no logic behind it. The theory and action just simply are not compatible, barring a freak accident, though this surely would have been rectified quickly. Oxygen deficiencies are also rare. Finally, on autopilot mode, the aircraft would not have deviated as dramatically as seen in this case. The dramatic flight deviation certainly seems to point towards some human involvement.

Theory 2: Catastrophic Aircraft Failure

Explained: Some form of system failure may explain the intricacies of this case. If a major issue, such as a system failure, happened, perhaps Captain Shah took unexpected steps – such as course changes – in a bid to save the aircraft and passengers.

For: System failures are rather rare, but can happen. The only normal reason for a change of flight path is an emergency situation. A system failure would be classed as an emergency. Had this, or a similar crucial function failure, taken place, it would explain the changes in flight path that were seen – perhaps Captain Shah wanted to divert the aircraft to an airport in a bid to find safety. With it also presumed that MH370 ended up in the ocean, this could feasibly be the cause. It is also possible that the aircraft continued to fly on as the crew desperately tried to rectify matters – fitting in with the fact that the plane flew for hours after communications were lost.

Against: Once again, the issue with this theory is that it doesn’t explain why communications were lost. It is possible that they were disabled by the Pilots on purpose – though there is little logic to support this. In fact, if the aircraft was in disarray, the last thing any crew member would do is turn off communications. Once communications were lost, it isn’t too feasible that the plane would just continue to fly for hours – surely the pilot would know roughly where to try and find a landing strip, and wouldn’t need several hours to do so.

Theory 3: Pilot Suicide

Explained: One of the darkest, but realistic, theories concerns either the pilot or co-pilot making the decision to take their own life. In doing so, they opted to do so in the most selfish way possible – taking hundreds with them. Captain Shah may have locked his Co-Pilot out of the cockpit, or vice versa, which would mean they would be uninterrupted in their plans. Or, one of them could have attacked the other, rendering them unconscious.

For: As mentioned before, MH370 took unexpected changes in its flight path. One such change saw the flight turning back around shortly after leaving Malaysia. Captain Shah grew up on the island of Penang, Malaysia. There have been suggestions that the aircraft was positioned into an angle that would allow the pilot a look at Penang. Some suggested this was to give Shah an ‘emotional farewell’ prior to death. Other course changes could have been done with the intention of keeping the aircraft out of any view. Perhaps the biggest evidence to suggest a pilot suicide is the fact that this could give an explanation as to communications being lost – especially as it seemed to involve some form of human involvement. Shah would be able to go about this act without any trace. Shah was reportedly having personal problems in the build-up to the flight, and had no social plans past the day of the flight. Moreover, as per Reuters, Captain Shah flew a route on his home flight simulator six weeks earlier that was “initially similar” to the one actually taken with MH370 – suggesting it might be premeditated. Shah has been seen as the main suspect, as Co-pilot Hamid was engaged to his girlfriend, loved his job, and was painted by his friends and family as an honourable man.

Against: Shah’s family have vehemently denied this was the cause. They stated that Shah was devoted to both his family and his job – and therefore this action would’ve been completely out of character. This is the ultimate act of selfishness, could Shah really have done this? Pilot suicides are rare occurrences. There is also the chance that Shah instead was the hero of the aircraft – he may have fought tirelessly to save the aircraft had it been in significant danger, such as the system failure theory outlined above. Or he could’ve steered the aircraft away from populated areas had they been in trouble – in a bid to minimise the number of lives being lost.

Theory 4: Fire

Explained: Similar to the suggestion of a system failure, a fire could be an explanation for the different circumstances seen. There have been various accounts of people who purportedly witnessed an aircraft on fire around the time of MH370’s disappearance. The cargo may have caused a fire, especially as it is known that lithium-ion batteries were on board – they contain the highly-flammable chemical lithium. A fire could have also feasibly started via other means.

For: A fire is a somewhat logical suggestion to this case. It would explain why, as presumed, the aircraft ended up in the water. It would also make sense for the plane to continue flying for hours after communications were lost, as happened. Many sightings were apparently made regarding a plane on fire – though nothing has ever been proven. As mentioned, Lithium-ion batteries were known to be in the cargo. These batteries can easily ignite – with something as simple as over-heating being capable of causing the fire. Perhaps most interestingly, there is precedent for unexpected fires affecting Boeing 777’s. One such aircraft caught fire while parked at Cairo Airport in 2011. The fault appeared to be with the hose used in the cockpit to provide oxygen in the case of decompression. While this happened on the ground, this same event could’ve happened in the air on MH370, which would have caused a fire – and led to the plane crashing in water. A fire may also explain a course change – if the pilots were trying to get the plane back to an airport.

Against: Despite this being a logical theory, there are plenty of questions surrounding this theory. Firstly, the sightings of planes on fire have never been proven. While Lithium-ion batteries were present, it is incredibly rare for them to catch fire, with the plane hold’s kept at a regulated temperature – making this highly unlikely. No other instance of a Boeing 777 catching fire spontaneously has been seen, other than the aforementioned Cairo instance. While a fire may partially explain the course changes, it doesn’t completely make sense – as the pilots were surely experienced enough to know where the nearest airport was. The lack of distress call being made as well only adds another question to this theory.

Theory 5: Passenger Hijacking

Explained: There have been countless occasions where a passenger or passengers has/have managed to overpower staff and reach the cockpit. The suggestion is that the hijackers would have aimed to use the aircraft as a weapon.

For: The fact that MH370’s flight path changed multiple times could be perfectly explained by a hijacking. The hijackers may well have changed course multiple times in order to avoid detection. This theory would also explain why communications were lost – as the hijackers would surely manually turn them off. It would also explain why the plane flew for hours after it disappeared from radars. If the hijackers were aiming to fly the aircraft into a populated area, the pilot and/or passengers may have attempted to wrestle control back from the hijackers, only for the aircraft to end up in the sea. Finally, co-pilot Hamid was believed to periodically invite women into the cockpit – which would’ve made it easier for a hijacking to take place.

Against: As mentioned previously, the effort put into solving MH370’s disappearance was simply enormous. While searches along the sea floor was the main part, significant work was also done to ascertain the backgrounds of passengers. Investigators mostly ruled out the possibility of a hijacking, after all backgrounds were checked, without anything questionable being found. No distress call was made, which is common procedure following a hijacking. When someone manages to hijack an aircraft, they normally do so to demand something. In this case, no such contact was made. It doesn’t make sense for a hijacker to go to the effort of said hijacking, only to then crash the aircraft into the sea. Finally, hijackings are rare, especially given the strength in cockpit security.

Vote: What Happened?

What Happened to Malaysia Airlines Flight 370?

The Takeaway

Regardless of whichever theory is true, it is important to remember that 239 people lost their lives as a result of the event. This is a tragedy, and has affected so many families around the world.

The hope is that one day there will be a full explanation of what happened. Until then, speculation will continue, with the case widely discussed.

Title Image Credit: Pray for my compatriots on Malaysia Airlines flight MH370.” by byeangel is marked with CC BY-SA 2.0.