– The plane must be somewhere. But the same can be said for Amelia Earhart’s.

Ten days after Malaysia Airlines Flight 370 disappeared with 239 people aboard, an exhaustive international search has produced no sign of the jet, raising an unsettling question: What if the airplane is never found?

Such an outcome, while considered unlikely, would certainly torment the families of those missing. It would also flummox the airline industry.

While such mysteries are rare nowadays, history is not short of them — from the most famous of all, American aviator Earhart, to planes and ships disappearing in the Bermuda Triangle.

“When something like this happens that confounds us, we’re offended by it, and we’re scared by it,” said Ric Gillespie, a former U.S. aviation accident investigator who wrote a book about Earhart’s still-unsolved 1937 disappearance over the Pacific Ocean.

“We had the illusion of control, and it’s just been shown to us that oh, folks, you know what? A really big airliner can just vanish. And nobody wants to hear that,” he said.

Part of the problem, said Andrew Thomas, the editor in chief of the Journal of Transportation Security, is that airline systems are not as sophisticated as many people might think. Airports and airplanes use antiquated radar technology, first developed in the 1950s, rather than GPS systems.

Experts said the plane’s disappearance will likely put pressure on airlines and governments to improve the way they monitor planes, including handoffs between countries.

Flight 370 vanished after it signed off with Malaysian air traffic controllers and never made contact with their Vietnamese counterparts.

If the plane is never found, liability issues will be a headache for courts. With no wreckage, it would be difficult to determine whether the airline, manufacturers or other parties should bear the brunt of responsibility.

It has been nearly 50 years since a plane carrying more than two dozen people vanished. An Argentine military plane carrying 69 people disappeared in 1965 and was never found.