Four leading aviation experts have agreed the disappearance of flight MH370 was the deliberate act of someone on board.

In a special 60 Minutes episode on Sunday night, reporter Tara Brown boasted the program’s expert panel would provide a “final reckoning” for the cause of the disaster.

Flight MH370 disappeared en route from Kuala Lumpur to Beijing on March 8, 2014 with 239 people on board, including six Australians. It remains one of aviation’s greatest mysteries.

The show’s expert aviation panel comprised former Australian Transport Safety Bureau head Martin Dolan, air crash investigation expert Larry Vance, veteran US pilot and air safety expert John Cox, and veteran Boeing 777 pilot Simon Hardy. It also heard from leading oceanographer Charitha Pattiaratchi.

Was this a “catastrophic accident or mass murder?” Brown asked. The verdict of the panel was unanimous.

“This was planned, this was deliberate, and it was done over an extended period of time,” Mr Dolan said.

“This was a criminal act,” Mr Vance agreed. He said the public should “take comfort” in this finding, as it ruled out a catastrophic malfunction that could be repeated in other Boeing 777s.

Simon Hardy was of the firm opinion that Captain Zaharie Ahmad Shah was the culprit. He based this on evidence the plane dipped its wing over Penang, the captain’s home town, possibly as a farewell.

“And after two months, three months of thinking about it, I finally got the answer – somebody was looking out the window,” Mr Hardy told 60 Minutes.

“It might [be] a long, emotional goodbye or a short, emotional goodbye to his hometown.”

The captain’s flight simulator, found in his home, had also plotted a one-way trip to the depths of the Indian Ocean, similar to MH370’s presumed flight path.

And the plane appeared to very deliberately dodge military radar along the Malaysian and Thai border.

“As the aircraft went across Thailand and Malaysia, it runs down the border, which is wiggling underneath, meaning it’s going in and out of those two countries, which is where their jurisdictions are,” Mr Hardy said.

“If you were commissioning me to do this operation and try and make a 777 disappear, I would do exactly the same thing.”

Others on the panel were warier of accusing the pilot personally. But they all agreed it was highly improbable the plane veered off course by accident.

“One in a trillion,” one expert said.

The only real disagreement between the panel was over whether the plane dove into the ocean at high-speed or was guided into a relatively soft landing on the waves.

The ‘death dive’ is disputed by veteran Boeing 777 pilot Simon Hardy. He believes MH370 was ditched in a controlled landing. This scenario would add an extra 100 nautical miles to the flight and raise fundamental questions about the current search area. #60Mins. pic.twitter.com/6lOJIDlIms

— 60 Minutes Australia (@60Mins) May 13, 2018

This would determine where and in how many pieces the plane might be found. But it did not affect the panel’s verdict. All experts agreed it was sent deliberately off course.

Mr Hardy said there was “no chance” of finding the plane if it was controlled to the end, as he believes. This was because the plane would have sunk relatively in one piece, to a depth that would make it very difficult to find.

Larry Vance said the captain must have flown the plane to its distant resting place in the Indian Ocean to ensure it was never found.

Mr Vance said the recovered flaperon – found relatively undamaged on Reunion Island in 2015 – proved there was a controlled landing not a destructive high-speed crash.

Veteran air-crash investigator Larry Vance supports the controlled landing theory and believes the majority of the aircraft is still intact. He says the discovery of MH370’s intact flaperon backs up his claim. #60Mins. pic.twitter.com/A1beejitd5

— 60 Minutes Australia (@60Mins) May 13, 2018

But the ATSB’s Mr Dolan defended his former agency’s prediction of an uncontrolled crash, which it had used to set the original search zone.

Under Mr Dolan’s watch, the ATSB’s four-year, $200 million search focussed on a part of the Indian Ocean that assumed the plane had flown unguided until it ran out of fuel and ditched into the ocean. Naturally, Mr Doland was reluctant to change his view, but admitted time was running out for this theory to be proven correct.

“If we don’t end up finding the plane within the search area, we will have got our priorities wrong, yes,” he admitted.

The Malaysian government has not commented on Captain Zaharie’s possible involvement in the plane’s disappearance.

It has signed a 90-day no find, no fee deal with US-based company Ocean Infinity, which is due to end its search of a new 25,000 sqkm search area in mid-June.

The panel agreed that it was unlikely that more funding would be spent on additional searches.

But the ATSB’s Mr Dolan said the conclusion that the crash was deliberate could be reached without ever finding the wreckage, based on the weight of evidence.