The Malaysia Airlines flight is only the latest mystery in a long line of aviation puzzles. From Amelia Earhart's fated flight to a World War II nuclear bomber, here's a list of the most mysterious airplane mishaps in history.

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1. Flight 19: Six Navy Aircraft Fall Victim to the Bermuda Triangle

At the height of World War II, the United States Navy dispatched five torpedo bombers on a routine training flight over the Bermuda Triangle. The Bermuda Triangle is somewhat famous for eating airplanes, so it is hardly surprising that all 14 crewmembers aboard the five military aircraft were never seen or heard from again. But hours later, the Navy sent an additional 13 men on a search-and-rescue mission in a Mariner flying boat . . . and, wouldn't you know it, they didn't return either. To this day, the fate of Flight 19 remains a mystery, and reminds us to just stay away from the triangle.
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2. EgyptAir Flight 990: Suicide Pilot or Terrorist Plot?

In 1999 an EgyptAir Boeing 767 departed from Los Angeles and then crashed into the Atlantic Ocean, killing all 217 passengers and crew. The Egyptian Civil Aviation Authority (ECAA) blamed mechanical failure, but the United States National Transportation and Safety Board (NTSB) suggested that the pilot committed suicide.

The pilot's last recorded words were, "I rely on God," so it was open season for speculation. Conspiracy theorists blamed the Mossad, the CIA, and Egyptian extremists, but we still don't know who or what actually knocked Flight 990 out of the sky. EgyptAir ultimately retired flight no. 990, and the company no longer runs the Los Angeles route at all.
   

3. Amelia Earhart: Sorry, We Had To

It wouldn't be a list of airplane mysteries without her. In 1937 Amelia Earhart vanished in a Lockheed Electra, never to finish her round-the-world flight. The only clues that Earhart and her Electra left behind were a few garbled (and disputed) radio transmissions.

We may never know what happened to Amelia Earhart after that doomed flight. The simplest theory—that she ditched her airplane and died at sea—has never quite satisfied popular imagination. The craziest theories have her captured and executed by the Japanese government or quietly living out her days in New Jersey under an assumed name. Regardless, this remains one of aviation's greatest unsolved mysteries. 
 
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4. Helios Airways Flight 522: The Stuff of Nightmares

In 2005, Helios Airways Flight 522 veered only slightly off course on its short hop from Cyprus to Greece, but the crew was ignoring all radio transmissions. After 19 attempts to contact the passenger jet, two F-16s scrambled to intercept the rogue airplane. As they flew alongside Flight 522, the F-16 pilots noticed that the captain's chair was empty, the copilot was lying motionless, and oxygen masks were dangling from the ceiling. 

Everyone on board was dead.

Hours after most of the 117 passengers and crew had suffocated, the autopilot remained engaged as the F-16s escorted the ghost plane until it crashed into a hillside in Greece. Subsequent investigations proved that the pilots had failed to pressurize the cabin, but simple explanations could not possibly satisfy those who revel in the possibility of a haunted aircraft.
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5. B47 Stratojet: A Nuclear Bomber Goes Missing

It's bad when three Air Force officers and a multimillion-dollar heavy bomber are lost at sea. It's even worse when that heavy bomber is carrying two nuclear weapon cores, the contents of which are never recovered.

In 1956 a nuclear B47 Stratojet disappeared over the Mediterranean Sea. We still have no idea what happened to the airplane, its crew, or either of its two nuclear bombs. The United States government has lost only 11 nukes in its history—so-called "broken arrows" that do not create a risk of nuclear war. But other broken arrows went down under less mysterious circumstances, and the B47 Stratojet's dangerous payload has yet to be recovered.
 

6. Aer Lingus Flight 712: Passenger Jet Taken Out by a Rogue Missile?

When a 1968 Aer Lingus crash killed all 61 people on board, an investigation determined that something unusual had brought down the passenger jet. Obvious deformities in the airplane's left tail suggested either serious corrosion or a bird strike, but several witnesses claimed that a British missile had taken down the jet.

Although the Brits vehemently dismissed the rumors of a rogue missile launch, some evidence suggests that such a scenario is at least possible, if unlikely. Almost 50 years later, we still don't know exactly what knocked Flight 712 out of the sky, but the British missile theory leaves many wondering whether a military mistake sent 61 civilians into the Irish deep.  

7. Pan Am Flight 7: Luxury Airliner Descends Into Legend

Billed as Clipper Romance of the Skies, Pan Am Flight 7 provided one of the most luxurious trips around the world back in 1957. But on one routine flight from California to Hawaii, the Boeing Stratocruiser disappeared without a trace. 

For five days, search-and-rescue teams scrambled to find the wreckage. Once the Clipper was finally found, however, the discovery raised even more questions. The Boeing craft was drifting in the ocean, miles off course, and autopsies suggested carbon monoxide poisoning. Even now, some speculate that the crash was an act of insurance fraud or revenge perpetrated by a disgruntled crewmember. 

8. Flying Tiger Line Flight 739: Military Scours the Pacific for 100 Lost Soldiers

In 1962 a Lockheed Constellation took off over the Pacific Ocean carrying 96 soldiers and 11 crewmen, and then disappeared forever. The military conducted one of the largest search-and-rescue missions in the history of the Pacific, but never found a trace of their lost soldiers.

Flying Tiger Line, an early cargo airline and military contractor, speculated that the flight had been hijacked or otherwise sabotaged, but admitted that they had no evidence to support their theories. Sailors aboard a Liberian tanker reported a fireball splashing into the sea, which suggests that Flight 739 exploded in midair. That was never confirmed. 
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9. Northwest Airlines and D.B. Cooper: A Hijacker Parachutes Into History

Although his antics never caused an airplane crash, D.B. Cooper's story is one of aviation's wackiest unsolved mysteries. In 1971 an unknown hijacker took control of a Boeing 727, forced the crew to land in Seattle, obtained $200,000 in ransom money, and released all of the passengers unharmed. He then ordered the pilot to take off and fly low over Mexico, where he parachuted to freedom.

The police never caught D.B Cooper. Popular media gave him his moniker, and a crude pencil sketch gives us an idea of what he looked like, but who exactly D.B. Cooper was and where he is now remains a mystery. Some suspect that he died after ejecting from the airplane, but others maintain that this aerial criminal is still at large, sipping cold drinks south of the border. 

10.British South American Airways Star Dust: One Mystery Finally Solved

Until 15 years ago, rumor and intrigue surrounded the story of Star Dust, an airliner that disappeared without a trace in 1947. Widespread searches failed to turn up any trace of the aircraft or its 11 passengers, and theories of spies, sabotage, and even alien abduction swarmed around tales of the lost prop plane.

But 50 years later glacial ice in the Andes melted to reveal wreckage that looked startlingly like Star Dust. We now know that the aircraft plunged into the snowy mountain range and, on impact, instantly buried itself in an avalanche. It took half a century of glacial melting, but this puzzle was finally solved.