What happened to MH370? The most (and least) plausible explanations
December 3, 2025
More than a decade after Malaysia Airlines flight MH370 vanished with 239 people on board, the search for the Boeing 777-200ER is set to resume on December 30, according to Malaysian officials in Kuala Lumpur. US robotics company Ocean Infinity, contracted by the Malaysian government, will conduct the search.
Ocean Infinity renews its search for MH370 with new analytical models and improved UAV technology
Ocean Infinity, which conducted an unsuccessful search for the missing aircraft in 2018, proposed the new search based on updated analytical models and improved autonomous underwater vehicle (AUV) technology, while narrowing the likely crash zone to a remote area of the southern Indian Ocean.
Its most recent search for the missing aircraft in the southern Indian Ocean took place earlier this year, but was suspended in April due to unfavourable weather conditions.
“Ocean Infinity has confirmed with the Government of Malaysia that it will recommence seabed search operations for a total of 55 days, to be conducted intermittently,” Malaysia’s Transport Ministry said in a statement issued on Wednesday, as reported by News Australia. “The search will be carried out in the targeted area assessed to have the highest probability of locating the aircraft.”
The disappearance of MH370 on March 8, 2014, remains aviation’s most perplexing modern mystery. While the new search raises hopes for closure, investigators continue to work from a small set of plausible theories, while the internet is full of implausible conspiracy theories.
The three most evidence-supported theories on MH370’s disappearance
These are the three most plausible theories on what may have happened to the Malaysian Airlines flight, though none can be proven unless the crash site is found and the flight data recorder and flight voice recorder are recovered.
1. Unresponsive crew event leads to a ‘ghost flight’
This is the scenario most strongly supported by satellite data and aircraft systems’ logic.
A sudden event — such as depressurisation, fire, or other incapacitating condition — could have left the crew and passengers unconscious. The aircraft would then have flown on autopilot until it ran out of fuel. This is consistent with the Inmarsat satellite handshakes, which showed the aircraft continuing for approximately 5.5 hours after the last radar data.
The theory aligns with the straight, stable southerly track, suggesting no human intervention in the final hours.
Supporting clues:
- Continued hourly satellite “ping” arcs.
- Lack of radio communications after the turn-back.
- Flight path consistent with autopilot operation.
2. Deliberate diversion by the pilot or another person with cockpit access
Investigators and various independent analysts have said the flight’s deliberate turn-back over the South China Sea and navigation along waypoints could indicate manual control during the first phase of the disappearance.
If this scenario is correct, the aircraft may have been intentionally flown into the remote Indian Ocean.
Supporting clues:
- The initial turn-back and waypoint navigation are hard to attribute to the system’s failure.
- Simulator data found in Captain Zaharie Ahmad Shah’s home computer included a route ending in the southern Indian Ocean (though not identical to the flight’s actual track and not considered proof of intent).
- The lack of a distress call.
Most agencies do not label this theory as likely — only plausible.
3. Catastrophic mechanical or electrical failure followed by partial crew response
Some argue that a cascading failure — such as an electrical bus failure, cockpit smoke, or an avionics malfunction — could have disabled communications and navigation equipment, forcing the pilots to attempt an emergency return.
The turn-back to Malaysia aligns with emergency-return logic, although it does not explain the long, stable flight afterwards unless the crew became incapacitated later.
Supporting clues:
- Some failure modes could simultaneously silence transponders and the radio.
- The flight’s initial return track roughly aligned with a path toward Penang or Langkawi, plausible diversion airports.
This theory requires a two-stage sequence: early flight crew action, followed by later incapacitation.
The three wildest conspiracy theories—debunked
Below are the fringe narratives that have circulated for years. None has supporting evidence, and many contradict known satellite and debris data.
1. The plane was flown to Diego Garcia
One of the most persistent conspiracies claims MH370 landed at the US military base on Diego Garcia.
Why it’s implausible:
- Satellite handshake data shows the aircraft flying south, not northwest to the Maldives/Diego Garcia.
- No radar, satellite or military tracking supports a diversion to the base.
- Debris confirmed from MH370 washed up in the western Indian Ocean, consistent only with a southern crash.
2. The aircraft was shot down or destroyed by a secret weapon
Variants of this conspiracy theory claim the plane was downed by the US, China, Malaysia or even a “black project.”
Why it’s implausible:
- No missile signatures, military radar corridors or acoustic evidence exist.
- Wreckage from a mid-air breakup would have dispersed near the last known radar position, not thousands of kilometres away.
- Multiple nations would have had to conceal an unprecedented covert shoot-down with no leaks for more than a decade.
3. MH370 was abducted by aliens or entered a wormhole or dimensional shift
These internet-viral ideas emerged from grainy YouTube videos and fictionalised posts.
Why it’s implausible:
- Satellite handshake data clearly tracks the aircraft until fuel exhaustion.
- Physical MH370 debris has been recovered, and Boeing has confirmed its authenticity.
- Debris was geolocated to drift models.
This was the loss of an aircraft in real-world conditions, if yet unexplained, not a supernatural disappearance. Still, conspiracy theories persist and multiply because they don’t need to conform to rational facts, which are sometimes far more difficult to come by.
A new search brings renewed hope for those waiting for answers
A successful find would resolve crucial questions for the victims’ families and provide insight into aviation safety, autopilot behaviour and the type of failure or deliberate act that caused the disappearance.
For aviation investigators, the priority will be to locate the flight recorders, which can survive deep-sea conditions and still hold recoverable data.
The Australian Transport Safety Bureau (ATSB) and Malaysia’s transport ministry have indicated they may re-engage international support depending on the mission parameters presented by Ocean Infinity.
“The reasons for the loss of MH370 cannot be established with certainty until the aircraft is found,” the ATSB stated in its October 2017 report on the aircraft’s disappearance. “It is almost inconceivable and certainly societally unacceptable in the modern aviation era with 10 million passengers boarding commercial aircraft every day, for a large commercial aircraft to be missing and for the world not to know with certainty what became of the aircraft and those on board.”
As the Malaysian transport ministry stated, the latest search reflects the government’s commitment to “providing closure to the families affected by this tragedy.” For those who lost loved ones on the ill-fated flight, a new search may finally bring some answers.
Featured Image: Ohconfucius | Wikimedia Commons
