There were more airline deaths worldwide due to deliberate acts in 2015 than to accidental air crashes for the second year in a row, according to an industry tally.
There were only eight accidental airline crashes last year accounting for 161 passenger and crew deaths - the fewest crashes and deaths since at least 1946.
The tally by Flightglobal, an aviation news and industry data company, excludes a German airliner that was deliberately flown into a mountainside in the French Alps last March, and a Russian airliner packed with tourist that exploded over Egypt in October. The toll for those two incidents was 374 killed.
In 2014, the toll from a Malaysia Airlines plane that disappeared and another that was shot down over Ukraine was 537 deaths compared to 436 accident deaths that year.
"In recent years, airline safety has improved very considerably to the point where, typically, there are now very few fatal accidents and fatalities in a year," said Paul Hayes, Flightglobal's director of air safety and insurance.
"However, flight security remains a concern."
The global fatal accident rate for all types of airline operations in 2015 was one per 5 million flights - eclipsing 2014, which had a fatal accident rate of 1 per 2.5 million flights, as the best year ever.
A big reason for the improving record is better engineering: Today's airliners and aircraft engines are far safer than earlier generations of planes and common pilot errors have been greatly reduced.
But more needs to be done to weed out disturbed pilots and guard against acts of terrorism, experts said.
The Germanwings case is especially perplexing, said John Cox, a former airline pilot and aviation safety consultant.
Pilot Andreas Lubitz managed to conceal his problems even though airlines are continually evaluating pilots for signs of trouble. Pilots evaluate each other as well.
It's not known what caused Malaysia Airlines Flight 370 to disappear while flying from Kuala Lumpur to Beijing.
But many aviation safety experts theorise that it was mostly likely the result of deliberate acts, probably by one of the two pilots.
"Pilots from day one are so ingrained with protecting the passengers, with learning skills to deal with unanticipated events ... and evaluated on how well you deal with stress," Cox said.
"Those who don't do well with it don't survive as professional pilots."
