The abrupt loss of contact with the Malaysia Airlines flight has led prominent aviation experts to speculate a catastrophe such as an explosion or lost freight door ended the plane's flight.
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Families upset by Malaysia Airlines response
Some Chinese relatives of the passengers on board a Malaysia Airlines flight that went missing off the coast of Vietnam are angry over what they say was the airline's initial lack of response.
Aviation expert and editor of airlineratings.com Geoffrey Thomas told Fairfax Media he suspected the plane was involved in a "sudden catastrophic explosion" because no mayday call or other warning was made.
Mr Thomas, who has been involved in the aviation industry for 35 years, speculated such an explosion could be caused by either a terrorist bomb or a cargo door ripping away from the craft.
But he pointed out the latter incident had not occurred widely since the 1970s, and had never occurred in the nearly faultless history of the Boeing 777 since it was launched in 1995.
In fact Mr Thomas said the craft has only been involved in one fatal crash – which was ultimately ruled to be "pilot error" – when the plane crashed into a runway seawall during a landing at San Francisco International Airport last year. Three people were killed and hundreds injured in the accident.
The prospect of foul play arose after Austria and Italy said that two passengers used passports stolen from their nationals, both of them men.
While there was no information pointing to a possible bomb or terror attack, Malaysia is studying all possibilities, Acting Transport Minister Hishammuddin Hussein told reporters.
The stolen Austrian passport belonged to a 30-year-old man who reported the theft in 2012 in Phuket, Thailand, the foreign ministry said. He was contacted and found to be "well," said Martin Weiss, a ministry spokesman. Luigi Maraldi, an Italian national also shown on the manifest, didn't travel on the plane, Foreign Ministry spokesman Aldo Amati said.
Other aviation commentators are reluctant to point to a cause, stating that a proper investigation is required.
"It's a very capable, impressive and quite luxurious vehicle," Central Queensland University aviation academic Ron Bishop told Fairfax Media.
There are currently 924 ''triple sevens'' in operation, with the largest fleet (of 87 jets) belonging to Emirates airlines. The aircraft is also used by Virgin.
"These are planes which have been trusted to fly long distances, over millions of hours. Everything is so tracked and measured with these jets, so it's very surprising to hear this news," Professor Bishop said.
"Things like this very, very rarely happen these days – you've got a better chance of winning the lottery."
Mr Thomas has dismissed any concerns the 27-year-old co-pilot may have been lacking the flight experience to operate the vehicle, considering he had 2700 hours' experience, compared to the 18,000 hours accumulated by his head pilot.
"Malaysia Airlines co-pilots have always been well-trained and this particular co-pilot has over seven years experience with the airline,'' Mr Thomas said.
"I do not believe this was pilot or aircraft error,'' he said.
If the aircraft is discovered to have crashed, investigators will aim to recover the aircraft's flight data recorder, which measures engine movements, hydraulics and technical indicators, and the cockpit voice recorder to determine the exact cause of the incident.
Professor Bishop noted the incident had occurred amid a significant increase in the number of passengers travelling over recent years.
"The average Australian flies about 2.5 times per year, and this kind of increase is occurring around the world. So it's the same principle as if there were more cars on the road – statistically, there's going to be an increased number of accidents," he said.
Aviation and crisis communication expert Hamish McLean said with over 5000 planes in the air at any one time, the occasional loss of an aircraft was a rare event, and particularly shocking considering the carrier belonged to a respected and well-known airline.
"There's a lot of uncertainty over what's happened, and the trouble is, all we have is speculation which just adds to the distress for the airline and the relatives of those passengers onboard," he said.