A former airline director has claimed that the US military may have shot down Malaysia Airlines flight MH370 in the latest theory about what happened to the missing plane.
Marc Dugain's speculation joins a long line of conspiracy theories as the mystery of the Boeing 777's disappearance continues almost 10 months on.
Military exercises, terrorist attacks, suicide, hijackings and plane faults have been blamed along with, inevitably, aliens.
No trace of the flight or its 239 passengers has ever been found, leaving even official investigators with the Australian Transport Safety Board to make guesses based on previous crashes.
The official report on MH370 said its passengers most probably died from suffocation as the cabin ran out of oxygen, leaving it to continue on auto-pilot until it ran out of fuel and plunged into the ocean.
But without evidence, that conclusion is unlikely to satisfy the thousands of conspiracy theorists touting these theories.
MH370 and MH17 were the same plane
Just months after the loss of MH370, flight MH17 from Amsterdam to Kuala Lumpur crashed in war-torn eastern Ukraine, killing all 298 people on board.
It was widely claimed that the accident was the result of a mistake by Ukrainian rebels, who reportedly shot at the plane believing it was an army aircraft, but the coincidence led some people to sensationally claim that it was MH370 in the air and the passengers were already dead.
Forum users claimed photographs from the crash scene showed the planes were one and the same and according to a pro-Russian rebel leader, the bodies had been dead days before the plane took off. In this theory, the passports were supposedly pristine and had been planted on the dead bodies.
Proponents have been unable to explain how anyone would manage to steal an airliner with 239 people on board, hide it for six months, sneak it into Amsterdam airport and swap it for a scheduled flight.
Plane taken to Pakistan
Retired US Lt Gen Thomas McInerney argued that MH370 was flown to Taliban-controlled Pakistan for later use against the US or Israel. “If the Pakistani government doesn't talk soon they're going to be complicit in this,” McInerney told Fox News, where he works as a military analyst.
Rupert Murdoch also raised the prospect on Twitter, writing: “Maybe no crash but stolen, effectively hidden, perhaps in Northern Pakistan, like Bin Laden.”
But analysis on satellite "pings" by British firm Inmarsat ruled out the Pakistan theory, showing that MH370 did not fly anywhere near the country's airspace.
Freescale staff targeted
Among MH370's passengers were 20 employees of US technology company Freescale Semiconductor, which makes powerful microchips for different sectors, including the defence industry.
It led to speculation that they held important industrial secrets. In one conspiracy theory, the US government feared they would fall into the hands of the Chinese authorities and hijacked it to take to a US military base on Diego Garcia, in the Indian Ocean.
At a conference last year, a security consultant called Hugo Teso hacked into virtual planes that were being flown on autopilot. He was using an android phone and an app he'd developed.
Several people have suggested that the plane's electronics could have been hacked from the ground, allowing hijackers to fly it wherever they wanted, but authorities said the plane's systems were secure.
Shot down in a military training exercise
Among those who support this view are the British journalist and author Nigel Cawthorne, who controversially published the first book on the plane’s disappearance.
At the time there was a series of war games taking place in the South China Sea involving Thailand, the US and personnel from China, Japan, Indonesia and others, and Cawthorne has linked this to witness claims to have seen a burning plane going down in the Gulf of Thailand.
Accident have happened before. Korean Air flight 007 was shot down by the Soviet Union in 1983, the US Navy downed an Iranian airliner in 1988, and MH17 appears to have been shot down by mistake. In all cases, the crashes were reported quickly.
Shot down deliberately, prompting cover-up
At a stage in the investigation when it was believed the plane could have flown for some time from where it disappeared along either a northern or southern corridor, many posted on forums suggesting that if it had been the former we would never hear about what happened.
Some still support this view, and former RAF navigator Sean Maffett told the BBC that after 9/11, any unidentified airliner entering the airspace of another country would lead to fighter jets being scrambled.
“If the plane is in the northern arc it could easily have been shot down,” he said. This theory also involves a national – or possibly international – cover-up, based on the premise that no country would want to admit to shooting down an airliner full of passengers from all over the world.
Mr Dugain's variant suggested that the US military shot it down near their base on Diego Garcia, in the remote Indian Ocean, fearing a terror attack.
Flown north in the ‘shadow’ of another plane
Another theory suggests that instead of flying south, the plane flew north in the “shadow” of another airliner after dropping off civilian radar.
The aviation blogger Keith Ledgerwood argued that MH370 and Singapore Airlines flight 68 were in the same vicinity at the time, and said: “It became apparent as I inspected SIA68's flight path history that MH370 had manoeuvred itself directly behind SIA68 at approximately 18:00UTC and over the next 15 minutes had been following SIA68.”
By flying a short distance behind and most likely a little above the altitude of SIA68, also a Boeing 777, Ledgerwood said that it would be able to appear as a single blip on radar screens.
Tried to land on a desert island beach
After reports that the plane had turned left shortly following its disappearance from civilian radar screens, speculation grew that it could have landed on a remote beach somewhere like the Andaman Islands, which lie between Indonesia and the coast of Thailand.
Though CNN reported that locals dismissed the idea a Boeing 777 could land on an airstrip there undetected, the archipelago consists of hundreds of remote islands with some long stretches of sand.
Former BA pilot Steve Buzdygan said it would be difficult – but not impossible – to bring a 777 down on a long deserted beach.
Landed at a US military base
One of the more outlandish conspiracy theories that has gained some traction online is the idea that MH370 could have been “captured” and flown to a military base on the UK-owned tropical atoll of Diego Garcia, in the middle of the Indian Ocean
The base is run by the US, and some have reportedly said in forum postings that the Kremlin has put some credence into this possibility.
Such is the strength of belief in this theory that the US government has been forced to issue a denial. A spokesperson for the US embassy in Malaysia told the local Star newspaper that there was “no indication that MH370 flew anywhere near the Maldives or Diego Garcia”. “MH370 did not land in Diego Garcia,” he added.
Headed for a remote airport in Langkawi, Malaysia
One theory, put forward by another aviation blogger named Chris Goodfellow, has it that the sudden left turn came after major catastrophe knocked out a range of the plane’s electronics, from transponders to communications equipment.
In this scenario and in the middle of the night, Goodfellow argued, the pilot would redirect towards the nearest safe airport.
“This pilot did all the right things,” he said. “Actually he was taking a direct route to Palau Langkawi, a 13,000ft (4,000m) strip with an approach over water at night with no obstacles. He did not turn back to Kuala Lumpur because he knew he had 8,000ft ridges to cross. He knew the terrain was friendlier towards Langkawi and also a shorter distance.”
This theory assumes that the plane was in fact controlled manually once it disappeared – and that it did not make it to Langkawi.
A fire throughout the plane
Many theories accept that the Inmarsat satellite analysis is accurate – that the plane headed south into the Indian Ocean and flew on for hours before a final, partial “handshake” in a remote location thousands of miles off the west coast of Australia.
The issue here becomes explaining what happened in the cabin between the last contact with flight controllers and the plane’s seemingly inevitable crash far out to see.
One suggestion is that a fire broke out, not just in the cockpit but throughout the interior of the plane. The implication is that this resulted in the attempt to turn back, after which the fire killed those on board.
This theory would then have it that the fire went out before damaging the exterior of the plane, which flew on autopilot until its fuel ran out.
Yet such a fire would be expected to spread with at least some warning – and that surely would have given the pilots time to issue a mayday distress signal.
An explosion in the cockpit
The theory of a sudden explosion within the cockpit before the turn left could explain why there was no attempt to signal for help.
Since 9/11 cockpits doors have been fortified to become extremely difficult to bypass, and such a sudden incident could perhaps have incapacitated both pilots while keeping out the rest of the crew.
This explanation does not seem to tally with the claims of some Malaysian officials, however, that the change in direction was the result of “seven or eight keystrokes into a computer on a knee-high pedestal between the captain and the first officer”.
A struggle at altitude
Though Malaysian officials believe that the plane was deliberately diverted, and that its communications systems were turned off one after the other, a detailed background check into all 227 passengers has cleared all of suspicion.
If, however, we do accept that the plane was the subject of a passenger hijacking, it remains to be explained why the hijackers did not try to do more than fly the plane into the middle of the southern Indian O
One theory suggests that there was some kind of struggle for control of the plane that ultimately ended with mutual destruction.
Further analysis of data by Malaysian officials suggests that the plane was flown erratically once it left civilian radar, climbing to 45,000ft before dropping very low. Buzdygan told the BBC he would resort to this sort of flying if faced with would-be hijackers. “I’d try to disorientate and confuse the hijackers by throwing them around,” he said.
A botched hijack attempt
The climb to 45,000ft could also have been carried out by the hijackers once they had taken control – in a bid to kill the passengers on board.
At such an altitude it could be possible to depressurise the cabin, causing oxygen supplies to be deployed. These run out after 12-15 minutes and, if those flying the plane had access to another oxygen supply, could have been an attempt to prevent anyone intervening.
Under this theory the suggestion is clearly that the attempt failed, killing the hijackers as well.
As part of the ongoing criminal investigation in Malaysia, police are looking into the state of mind and possible motives of the captain Zaharie Ahmad Shah and co-pilot Fariq Abdul Hamid.
The Malaysian police chief Khalid Abu Bakar has said that “all possibilities” will be looked into, and there have been reports that Shah was going through a difficult marriage break-up and had cleared his diary of all commitments after the flight.
Such comments have been rubbished by the man’s relatives and Malaysia Airlines, who have described him since as a dedicated family man and model professional.
The inquiry made him the most likely culprit if the plane was lost due to human intervention but does not rule out terrorism or mechanical failure.
Sabotage – for a life insurance scam or corporate attack
One of the other strands of the criminal investigation regards whether the plane was subject to some form of sabotage – either as part of a life insurance scam or over industrial espionage.
Bakar said that when passengers and crew were being investigated, police were looking for “Maybe somebody on the flight has bought a huge sum of insurance, who wants family to gain from it or somebody who has owed somebody so much money, you know, we are looking at all possibilities.”
A CIA cover-up
Finally, the former prime minister of Malaysia Mahathir Mohamad has waded in with his own theory – suggesting that, one way or another, the CIA is definitely hiding something.
In a blog entry posted on 18 May entitled ‘Boeing Technology – What goes up must come down’, Dr Mahathir Mohamad makes ten claims including that the plane was taken over remotely by officials working for Boeing and the CIA
“The plane is somewhere, maybe without MAS markings,” reads Dr Mohamad’s post on chedet.
“Someone is hiding something. It is not fair that MAS and Malaysia should take the blame,” 88-year-old Dr Mahathir, who was Malaysia's prime minister between 1981 and 2003, alleges.
“Airplanes don’t just disappear,” he said, concluding: “For some reason the media will not print anything that involves Boeing or the CIA. I hope my readers will read this.”
Boeing have denied Dr Mohamed’s theory.
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