As the spotlight falls on Dutch crash investigators and their high profile probe into the downing of a Malaysian airliner, air accident detectives worldwide are waging a much more discreet daily battle to keep flying safe.

The Dutch team’s findings, concluding that the plane was shot down by a Russian-made missile over eastern Ukraine in 2014, provoked an angry reaction on Tuesday from Russia, which dismissed their report as biased.

But despite the shooting down of Malaysia Airlines MH17, the disappearance of sister plane MH370 and an apparent Germanwings suicide crash in the Alps, the last year has brought the lowest accident rate in memory.

This is in large part due to the work of the crash investigators, who are quietly marking the centenary of the creation in Britain of the world’s first crash analysis agency.

Investigators now have to juggle growing challenges, from conflict zones to drones, dizzying automation, poor pilot training and questions over their own independence.

Topping the list, a series of incidents in which pilots erred when abruptly handed back control has drawn attention to a loss of skills brought about by modern reliance on computers.

“I don’t think there is any replacement for more flying around and getting experience,” Keith Conradi, Britain’s chief air accident investigator, told Reuters in a recent interview.

“The issue of automation is a real one. I do get concerned that it could bite us,” said Conradi, whose Air Accidents Investigation Branch marks its centenary on Wednesday.

Training is Key Issue

At a recent gathering of global investigators, France’s BEA investigation agency presented a damning report about an incident in 2014 when an ill-trained, fatigued and poorly regulated crew overshot the runway at Lyon.

Over 180 passengers and crew had a lucky escape when their jet stopped short of a 15 meter-deep hole in the ground – itself the result of a regulatory anomaly. It was later filled in.

“Everyone agrees that training is the number one issue today,” BEA Director Remi Jouty told Reuters.

European plane maker Airbus says that each new generation of computers halves the accident rate.

But the complexity of modern aircraft systems can tax even the resources of investigators when things go wrong.

“The speed of technology is very hard for investigators to follow. It is no longer possible to know all the systems, you need the experts from industry,” Ulf Kramer, head of Germany’s Federal Bureau of Aircraft Accident Investigation (BFU), said.

That worries some investigators who point out they are reliant on manufacturers to help them discover potential flaws. “We have the same overall objectives, but our short-term objectives can be different,” Jouty said.

Skill Shortages

The degree of reliance on the industry’s own investigators’ firepower emerged during the grounding of Boeing’s high-tech 787 Dreamliner jets in 2013 after a series of battery problems.

As its flagship product remained grounded, the U.S. company produced a “man-year” of data every day to try to find the root cause of the battery problems, a feat far beyond the capacity of all but the largest government safety agencies.

Investigators fret about other potential threats to their independence – from politicians turning up at crash sites to pressures from media, lawyers and family groups.

Many countries have yet to set up independent air crash investigation agencies, which are recommended by the United Nations’ aviation arm, as a means of keeping flying safe.

Record numbers of planes on order have meanwhile led to shortages of pilots and mechanics and encouraged some airlines to take short cuts in recruiting staff.

“The entire industry faces severe shortages in both fields,” said Frank del Gandio, a former FAA official who heads the International Society of Air Safety Investigators (ISASI), which devoted a recent annual safety summit to issues of independence.

Still, he and other safety veterans say the system of factual and blame-free reports dating back to World War One, coupled with new technology, has saved countless lives.

A result of that success is that the “go teams” of forensic crash experts are being called into action less than before and more attention is being spent on learning from lesser incidents.

“We don’t have a lot of accidents now. When I started as an investigator in 1980 I did 45 accidents and incidents in five years. You get some investigators now who won’t do 45 if they live to be 200,” Del Gandio said. “Aviation is safe. You are in more danger going home in a car than in an airplane,” he added.