On March 8, 2014, the Boeing 777-200ER of Malaysian Airlines Flight 370, flying from Kuala Lumpur to Beijing, vanished off the radar screens. The apparently impossible disappearance of the plane with its 239 passengers and crew on board turned it into one of the most inexplicable mysteries aviation had to present in the 21st century. Even years on, despite what was one of the most extensive searches ever undertaken, pieces of the plane have been washing up on the most inaccessible shores of the Indian Ocean, and yet its ultimate fate-what actually caused Flight 370 to vanish-really is a mystery. Theories piled up, investigations, and questions unanswered are what have kept this tragedy right in the forefront of global intrigue over the years.

 The Final Moments

Flight 370 disappeared immediately and unsettled many. It departed Kuala Lumpur International Airport at 12:41 AM local time. It was expected to arrive in Beijing at 6:30 AM. Graciously uneventful was this first flight. Just around 1:19 AM, the last communication, innocuous as well—a “good night” message—received from air traffic controllers would mark the last time the flight crew of the plane would contact anything.

Less than an hour later, around 1:37 AM, the plane’s transponder-a device that broadcasts information about altitude and position to air controllers-mysteriously switched off. This was followed by the plane diverting off course: northeast toward Beijing turned west over the southern Indian Ocean in an unexpected flight path.

In fact, except for a type of flight tracking technology known as “satellite handshakes,” everything else had stopped tracing the movement of the plane. It was these exchanges or handshakes between the satellite communication system aboard the plane and the ground network that brought in hourly information about the whereabouts of the aircraft. The final handshake came at 8:19 AM, which showed that the aircraft was still flying-but its exact position was unknown. Then Flight 370 simply vanished.

The Search Begins

The initial response to the disappearance was chaotic. Initial searches began in the South China Sea where the plane was believed to have crashed. But after days of fruitless searching over areas where wreckage was expected to be, attention turned toward the southern Indian Ocean, where the plane’s last known satellite communication was detected. It marked the beginning of probably one of the largest, most complex air searches in aviation history by area, technique, and millions of dollars spent.

The search area involved thousands of miles of open ocean, and though several fragments of the plane had been recovered to date-including a wing flaperon that washed up on Reunion Island in 2015-the bulk wreckage itself remained elusive. A confirmed identification proved that the flaperon belonged to MH370, but it had seemingly only deepened the mystery. Just where could this huge plane have been-a Boeing 777, in effect-and just disappear utterly, leaving no sign of significant debris anywhere in such a vast remote area?

Satellite data combined with an analysis of the flight path eventually whittled the Australian-led search down to a 120,000-square-kilometer swath of ocean-called “the 7th arc.” In 2018, the official search was called off with just a few pieces of wreckage found. It’s been upwards of six years since MH370 disappeared and the bottom of the ocean is keeping mum over the incident.

 What We Still Don’t Know

While some answers have come over time, most questions relating to Flight 370’s disappearance remain unexplained and feed speculation and conspiracy theories.

 1. What Happened to the Plane’s Communication Systems?

But probably the most perplexing aspect about the disappearance of MH370 was how communications from the plane had been shut off. A transponder that would have continuously broadcast the position of the aircraft in real time to air traffic controllers had been deliberately shut down-but nobody knew just why. An aircraft then continued to fly for hours after disappearing on course deep in the Southern Indian Ocean.

Was this an act of sabotage, or could it have been a malfunction? And who or what was responsible for the deliberate shutdown of the plane’s communication systems? These are questions which may never be answered, but with the timing of turning off the transponder, it really heightens suspicion to think that someone on board may have been capable of it.

 2. Was It the Fault of the Pilots?

The flight crew-especially the captain of the aircraft-received quite some attention in the days and weeks since Flight 370 vanished. Captain Shah was an experienced and well-respected 53-year-old pilot with upwards of 18,000 hours in the skies. Disturbingly, his personal life held some shocks: a flight simulator in his house did seem to approximate the last moments’ flight path of MH370.

Other theorists believe that he might have taken the plane off course due perhaps to personal distress or even an act of terrorism. However, no concrete proof has been found yet that links Shah with any intentional crime committed. His family denied the allegations and, just like the co-pilot, his mental state remains in question.

While various theories about the involvement of the pilot have been forwarded, they remain all speculative. Other possibilities cannot be ruled out in the absence of concrete evidence.

 3. Was There a Mechanical Failure?

That would also be quite well explained by a type of mechanical failure-the strange disappearance: through an in-flight fire, through depressurization, or through the failure of an important flight system that may have incapacitated the crew and passengers, and after that, the plane would drift away from its course.

This farfetched theory, in which the plane continued to talk to satellites for several hours after the transponder was disabled, is what most analysts say just shows that somehow the plane was in control. Much earlier on, a complete loss of control of the flight would probably have occurred in case a mechanical failure had taken place. The mechanical failure theory is hence less believable and not outright rejected.

 4. Was It Hijacked?

The most chilling of the many theories to have surfaced in the wake of the disappearance of Flight 370 is hijacking. Considering that its flight path was erratic and communications systems were disabled on purpose, many led themselves to believe that a hijacker may well have taken over the aircraft.

If hijacked, where did the plane go? Some believe that it might have landed at some remote airstrip, while others propose that the aircraft was deliberately flown into the ocean to cover up the hijacking. Though many different investigations were conducted, nothing really came up as concrete evidence for the theory of hijacking, though it remains a very important part of the conspiracy discussions related to MH370.

5. Could It Have Been a Terrorist Attack?

One of the many theories put across is that Flight 370 was a victim of a terrorist attack. While no terrorist group has claimed responsibility, not everything can be completely ruled out regarding terrorism either. If this was indeed so, a reason for such an attack and how the plane could have been hijacked or sabotaged is also not known.

But all this is very speculative, since no one has claimed responsibility, and there is no apparent motive or political agenda behind the act, considering how big in proportion the implications of a terrorist attack-let alone with such a modern, large aircraft like the Boeing 777-would be regarding security within air travel.

 6. Could There Be a Cover-Up?

Others go further to claim that what might have caused the disappearance of the plane may actually be concealed by the concerned parties’ governments, notably Malaysia. Some have theorized that evidence not being revealed to the public are for political or economic reasons, and that the real nature of what happened to Flight 370 could be far more diabolical than the authorities would like to admit.

All these theories hinge on the hypothesis that some areas of the research have been withheld from the press and the masses, either out of something to hide for those who would deliver the news or simply through incompetence on the part of such personnel. None of these has surfaced to date; the interest across the globe to discuss this very issue, as well as areas where no information has been divulged, have led to this proliferation of a variety of these theories.

 7. Could the Plane Have Been Remotely Controlled?

Another outlandish theory is that Flight 370 was being remotely controlled-by hackers or due to some malfunction of the on-board system of the aircraft. Some further suggest that “the flight management system of the plane could have been hacked and an outside party might take control of an aircraft.” There is no evidence that has cropped up to lend credence to this theory, which, all things considered, most aviation experts hold to be highly unlikely.

Mystery Without An End

The mystery of Flight 370 has not been resolved to date. After all those exhaustive search efforts, technological improvements, and the several thousands of hours that investigators have spent, much of the disappearance of MH 370 still remained a bundle of uncertainty: what made the aircraft veer off course, and finally, what happened to the plane and its passengers may never be found out.

The disappearance of Flight 370 was a tragedy that kept the world intrigued, frustrated, and brought immense sorrow to the families of flying passengers. Years later, it also serves as a grim reminder that even in these fast-forwarding days, human knowledge is limited and some questions are never fully answered.