The safety record of the Malaysia Airlines Boeing 777-200, which is feared to have crashed near Vietnam with 239 people on board, is "superb", an aviation expert has told Sky News.
However, David Learmount said the aircraft's sudden disappearance without sending out a distress signal had echoes of the Air France Airbus A330 that crashed into the South Atlantic in 2009, killing all 228 passengers.
The loss of the plane would be the worst involving the Boeing 777-200 since it entered service 19 years ago, although it would be the second fatal accident involving the aircraft in less than a year.
An Asiana Airlines Boeing 777-200ER crash-landed in San Francisco in July 2013, killing three passengers and injuring more than 180.
Despite this, Mr Learmount said the plane's safety record was "absolutely superb".
"Aviation safety now is quite extraordinarily good," he said. "It's far better than it was 20-30 years ago - I mean massively better.
The same type of aircraft crashed less than a year ago in San Francisco"That's why things like this are so surprising. They just should not happen any longer.
"The likelihood of this having been something catastrophic having happened to the aeroplane, just forget it. It wasn't that. Catastrophic things do not happen to modern aeroplanes. They just don't."
Mr Learmount added: "The extraordinary thing is that this aircraft has gone missing without the pilot saying a single word.
"The aircraft would have been at cruising height which is nice and high, which if anything goes wrong gives the pilots plenty of time to talk to people. So why didn't they?"
There was no suggestion that a bomb had exploded on board, Mr Learmount said.
Pointing to the loss mid-Atlantic of the Air France flight, he added: "It happened just like this one.
Wreckage from the Air France flight in 2009 is recovered from the Atlantic"The pilots didn't say anything but they could have done, as they had been in touch with air traffic control not long before the aircraft went missing. The aircraft just went down into the sea.
"We knew that there was a minor glitch on board the aeroplane, but it was very minor and only lasted for less than a minute, but it confused the pilot to such an extent that they never regained their composure.
"The reason why this is a possibility is that this Malaysian disappearance happened at the same time of day, about 1 or 2am local time, when people are at their lowest level of mental and physical capability."
:: Watch Sky News live on television, on Sky channel 501, Virgin Media channel 602, Freeview channel 82 and Freesat channel 202.