These are the world’s weirdest aviation mysteries
LAST week, a single photograph appeared to solve one of history's greatest aviation mysteries - what happened to Amelia Earhart?
The fate of the pioneering aviator has captivated the world ever since she went missing without a trace during a flight over the Pacific Ocean in 1937.
A photograph, released last week, that appeared to show Earhart in Japanese captivity after she went missing, fanned the theory the pioneering pilot had survived a plane crash - but other historians have since cast doubt on the theory. And so the Earhart mystery lives on.
But that is only one of many puzzling aviation mysteries that continue to grip the public's imagination, even though we still have no idea what really happened.
Here are some of the most famous ones.
1. AMELIA EARHART
Earhart, the first woman pilot to fly solo across the Atlantic Ocean, was on a mission to circumnavigate the globe with navigator Fred Noonan when her plane disappeared over the Pacific Ocean in 1937, after it took off from Papua New Guinea.
No trace of Earhart, Noonan, or their twin-engine Lockheed Electra, was ever found. Did the plane crash and if so, did Earhart die or survive it?
A number of theories have swirled in the 80 years since - from Earhart faking her death to alien abduction - but fresh developments in the past year have kept the speculation alive.
In October, scientists found a striking similarity between the missing pilot and the partial skeleton of a castaway found on an island of Kiribati in the South Pacific in 1940.
And last week, a History Channel documentary claimed to have found evidence Earhart and Noonan survived and were taken prisoner by Japanese forces.
It cited a black-and-white photograph, discovered in the National Archives in Washington, which supposedly showed the pair in the Marshall Islands after their capture.
But many have rubbished the photo. Military expert Matthew B Holly told AFP it appeared to have been taken about a decade earlier.
"From the Marshallese visual background, lack of Japanese flags flying on any vessels but one, and the age configuration of the steam-driven steel vessels, the photo is closer to the late 1920s or early 1930s, not anywhere near 1937," he said.
2. DB COOPER
In 1971, a man in a business suit boarded a Seattle-bound Northwest Orient Airlines flight in Portland, Oregon, carrying only a suitcase.
The man, known only as DB Cooper, told a flight attendant his suitcase contained a bomb, and demanded four parachutes and the current-day equivalent of about $1.6 million as ransom.
When the Boeing jet touched down at Seattle, Cooper let passengers get off and stayed on the plane, directing the pilot to fly to Mexico. As the jet approached Reno, Nevada on the way to Mexico, Cooper opened a rear door, jumped out and was never seen again.
In the 45 years since, no trace of Cooper's body has been found and no one really knows who he was.
Hundreds of theories emerged over the years. Some people said Cooper was a former paratrooper. Various families claimed Cooper was their relative. Someone pointed out the entire hijacking was eerily similar to the events of a 1963 French comic called Dan Cooper.
The mystery was so baffling, last year the FBI formally abandoned the hunt for answers.
But in January, citizen sleuths who had been carefully chipping away at their own investigations announced a possible breakthrough - that a fragment of Cooper's tie suggested he may have been a Boeing employee.
In the greatest aviation mystery of recent times, Beijing-bound Malaysia Airlines flight 370 vanished after departing Kuala Lumpur International Airport on March 8, 2014.
The Boeing 777-200ER was carrying 227 passengers, including six Australians, and 12 crew. It last made contact with air traffic control while it was flying over the South China Sea, less than an hour after takeoff, and it disappeared from radar just minutes later.
A multinational investigation has failed to find the missing plane. In January this year, search crews wrapped up their deep-sea sweep of 120,000 square kilometres off the west coast of Australia, and the search for MH370 - the most expansive and expensive search in aviation history - was officially called off.
"Despite every effort using the best science available, cutting-edge technology, as well as modelling and advice from highly skilled professionals who are the best in their field, unfortunately, the search has not been able to locate the aircraft," the Joint Agency Coordination Center in Australia said in a joint communique between the transport ministers of Malaysia, Australia and China.
The news came as no comfort to the families of missing Australian passengers Rod and Mary Burrows, Robert and Catherine Lawton, and Gu Naijun and Li Yuan, as well as Australia-based New Zealand man Paul Weeks.
4. BERMUDA TRIANGLE
This region between Florida, Puerto Rico and Bermuda is famous for one thing: claiming countless planes, ships and people, without any explanation.
The mystery of the Bermuda Triangle has captured the imagination of millions and baffled researchers. And while the subject is often the stuff of science fiction and supernatural stories, it's not all as farcical as you may think: in May this year, a plane carrying four people, including a mother and her two children, went missing in the infamous Bermuda Triangle, sending the world into a frenzy.
Many say there are mysterious forces at play in the dreaded region, although that's been rubbished by authorities.
In October, a new theory suggested clouds over the Bermuda Triangle were linked to powerful "air bombs" that could be behind the area's curious disappearances.
Meteorologists using radar satellite imagery discovered weird, "hexagonal" shaped clouds between 32km and 80km wide forming over the area unofficially designated as the Bermuda Triangle.
"The satellite imagery is really bizarre," metrologist Dr Randy Cerveny said. "These types of hexagonal shapes in the ocean are in essence air bombs. They're formed by what is called microbursts and they're blasts of air."
Dr Cerveny said the blasts of air were so powerful they could reach 273km/h - a hurricane-like force easily capable of sinking ships and downing planes.
5. EGYPT AIR FLIGHT 990
Flight 990 was a scheduled flight from Los Angeles to Cairo with a stopover in New York. But on October 31, 1999, the Boeing 747 mysteriously crashed into the Atlantic Ocean about 100 miles south of Nantucket, Massachusetts, killing all 217 people on-board.
While investigators never discovered the specific cause of the crash, the FBI believed that the evidence suggested the crash was deliberate rather than accidental.
Egyptian and American authorities never agreed on the cause of the crash, with the Egyptians concluding it was due to mechanical malfunction and the Americans stating it was the responsibility of the relief first officer.
6. PAN AM FLIGHT 7
Pan Am Flight 7 was once considered one of the most exclusive and luxurious "around-the-world trips" available.
But in 1957, during a leg from Los Angeles to Hawaii, the Boeing Stratocruiser vanished into thin air.
Rescue crews hunted for five days before finding the plane floating in the ocean, hundreds of miles off course, with very little actual damage to the aircraft.
Autopsies on the passengers found that they had been poisoned by carbon monoxide emissions, but no reason for the poisoning was ever found.
Many speculated that it was possibly an act of insurance fraud.