Editor's note: This story was originally published on March 11, 2014, during the search for missing Malaysia Airlines Flight 370.
First there was Malaysia Airlines Flight 370. Now there's AirAsia Flight 8501.
MH370 vanished without a trace on March 8, while carrying 239 people en route from Kuala Lumpur to Beijing.
AirAsia Flight 8501 disappeared Sunday while traveling from the Indonesian city of Surabaya to Singapore. There were 162 people on board. A search is underway, but the head of Indonesia's search and rescue agency says he believes the plane has crashed and sunk to the sea floor off the coast of Indonesia.
The disappearance of MH370 looks to be a mystery that will never be solved, but it's too early to know what we'll learn during the search for the AirAsia flight.
What we can say for sure is that these two flights weren't the first and won't be the last to disappear or crash under mysterious circumstances.
Here are five of the strangest aviation-related crashes and disappearances the world has known:
1. Amelia Earhart
The first woman to fly solo across the Atlantic Ocean, Amelia Earhart disappeared during an attempt to fly around the world in 1937.
She and navigator Fred Noonan were last heard from near Howland Island in the central Pacific Ocean.
In her last known transmission at 8:43 a.m. on July 2, Earhart broadcast "We are on the line 157 337. We will repeat this message. We will repeat this on 6210 kilocycles. Wait."
But nothing more was heard from the American aviation pioneer.
No definitive wreckage has ever been found.
2. Flight 19
On Dec. 5, 1945, five US Navy aircraft disappeared during a training flight in what would spark the legend of the Bermuda Triangle.
The 14 airmen, led by experienced instructor Charles Taylor, took off from Fort Lauderdale, Florida, in sunny conditions.
But an hour and a half into their flight, they reported they had become disorientated and couldn't recognize the landmarks below them. Taylor told the Naval Air Station via radio that his compasses had stopped working.
The weather deteriorated, and it's presumed the pilots made forced landings in the water. No trace of the aircraft was found.
What's even weirder is that one of the planes sent to look for them also disappeared.
3. Glenn Miller
Glenn Miller, a legendary big-band leader, was on his way to entertain US troops in France when his airplane disappeared over the English Channel in 1944.
The single-engine UC-64 Norseman departed from a Royal Air Force base north of Bedford, England, on Dec. 15 and was never heard from again.
No trace of the crew, passengers or aircraft has ever been found.
Miller left behind his wife and two adopted children. His status remains "missing in action," as seen in the photo above.
4. EgyptAir Flight 990
(Don Emmert/AFP/Getty Images)
Heading to Cairo via New York, EgyptAir Flight 990 crashed into the Atlantic Ocean south of Massachusetts in 1999, killing all 217 people onboard.
There are two very different theories as to why it crashed.
The National Transportation Safety Board found co-pilot Gamil el-Batouty at fault, alleging he had committed suicide for unknown reasons by nosediving the plane into the water below.
But the Egyptian Civil Aviation Authority blamed the crash on the mechanical failure of the plane's elevator control system.
Even stranger are the cockpit voice recordings recovered from the wreckage, in which el-Batouty is heard softly saying "I rely on God" after the captain had left to use the bathroom. He repeated the phrase at least seven more times, switching off the engines before the plane pitched downward.
5. Air France Flight 447
(Eric Cabanis/AFP/Getty Images)
This Airbus A330 disappeared over the Atlantic Ocean in 2009 while carrying 228 passengers and crew from Rio de Janeiro to Paris.
The final crash report suggested ice crystals had obstructed tubes in the aircraft, causing the autopilot to disconnect.
Crew members tried to recover control, but the aircraft plunged into the waters below. The official report suggested human error was a contributing factor.
It took five days for crews to even find the wreckage and another three years to determine the crash's cause. Most of the bodies were recovered in the months that followed, but 74 passengers were never found.
It became known as the deadliest crash in Air France's history.