Air investigators probing the flight MH370 tragedy have called for airline pilots to be screened for mental health issues to prevent 'suicide flights'.
Carriers must begin "rigorous and regulated" testing to identify pilots and cabin crew who may pose a risk to passenger safety, they say.
The results of these checks should be made public so fliers can be certain that their pilot does not pose a danger.
Airlines are currently required by international law to conduct regular screening for drug and alcohol misuse.
But they are not obliged to test for mental health problems, including severe stress, and none of the world's largest carriers have volunteered to do so.
This "gaping hole" in pre-flight safety could lead to other cases of pilot-driven murder, which some experts believe took place on board missing flight MH370.
Ewan Wilson, a New Zealand-based air accident investigator who studied the tragedy, believes all 239 passengers died from asphyxiation after pilot Zaharie Ahmad Shah depressurised the cabin hours before he deliberately crashed into the Indian Ocean.
He believes airlines have a duty of care to publish information about pilots' mental health and any incidents of drug or alcohol misuse.
Wilson, the founder of New Zealand's now defunct national carrier, Kiwi Airlines, spent more than four months researching the Malaysian disaster.
His book 'Goodnight Malaysian 370', which he co-wrote with New Zealand journalist Geoff Taylor, claims the tragedy could have been avoided with more stringent screening.
"It is shocking to think that international airlines are not required to routinely test their pilots for mental health irregularities, despite the terrible threat that those pilots and their crew pose to significant numbers of innocent people," he said.
"Our research strongly suggests that Zaharie Ahmad Shah committed an act of mass murder before taking his own life. It was fortunate that he chose to do so over the Indian Ocean, and not in a densely populated city; had he opted for the latter, tens of thousands of people might also have perished.
"There has never been a more compelling or necessary time to screen pilots and other flight staff as there is now. Passengers have the right to know that they will be kept safe from all dangers other than mechanical failure and an act of God."
The researchers, who spent four months analysing Flight 370, believe that all carriers should be required to fit their aircraft with 'glass boxes' - state-of-the-art in-flight safety monitoring systems that transmit location and other data in real time.
These would replace 'antiquated' black boxes, which only have a 30-day battery life once immersed in water. The last signal heard from Flight 370's black box was in April.
But what technology cannot protect against, they say, is the "rogue pilot".
Wilson and Taylor are now calling on the world's airlines to introduce regulated screenings to monitor mental health and stress levels among crew.
Pilots are "highly unlikely" to volunteer mental health issues of their own accord because it could spell the end of their careers, they argue.
Regular screenings, conducted by trained mental health professionals, would identify "early warning signs" and lead to appropriate risk-management strategies being put into place - such as removing at at-risk pilot from the cockpit.
Only those pilots who can demonstrate a clean bill of mental health should be allowed to sit at the controls.
And in the interests of public scrutiny, airlines should publish moderated, sensitised versions of its screenings, perhaps in the form of a register.
"Otherwise, the only other possible remedy is for the travelling public, where possible, to make choices based upon what they know to be safe airlines, with the players prepared to open their scrutiny of flight crews' mental health to international standards," Taylor said.
The researchers believe there have been five incidents of pilot suicide on commercial flights in the last 32 years. Excluding those who died on Flight 370, these have been responsible for the deaths of 422 people.
Wilson said: "Surely, if Ahmad Shah did commit the unfathomable, unforgiveable act we suggest, it must prompt another look at mental health in the cockpits of the thousands of aircraft in the world's skies."
But despite the loss of life on Flight 370 and widespread calls for better in-flight safety, Taylor said the chances of airlines voluntarily introducing mental health screenings are "remote".
He added: "The pilot's health should be beyond doubt. If the industry is not open to such things, they will continue to get tragic, nasty surprises. Surely, they are doing passengers more of a service by confronting issues early.
"We are, however, not hopeful of significant change."