KUALA LUMPUR, Malaysia (AP) — More than a decade ago, Malaysia Airlines Flight MH370 disappeared without a trace, spawning one of aviation's most baffling mysteries.
Despite years of international searches, investigators still don't know exactly what happened to the plane or its 239 passengers and crew.
The Malaysian government said Wednesday that U.S. marine robotics company Ocean Infinity will resume searching the seabed for the missing plane on Dec. 30, raising hopes that the plane may finally be found.
A massive search in the southern Indian Ocean where the plane is believed to have crashed has turned up little. With the exception of a few small fragments that washed ashore, no bodies or large debris were ever recovered.
Here's what we know about the deadly plane tragedy.
“Good night, Malaysian Three Seven Zero”
The Boeing 777 disappeared from air traffic radar 39 minutes after taking off from Kuala Lumpur to Beijing on March 8, 2014.
The pilot's final radio call to Kuala Lumpur – “Good night, Malaysian Three Seven Zero” – was the last message before the plane crossed into Vietnamese airspace and was unable to contact controllers there.
A few minutes later, the plane's transponder transmitting its location went offline. Military radar showed the plane turned over the Andaman Sea, and satellite data showed it continued to fly for several hours, possibly until it ran out of fuel, before crashing into a remote part of the southern Indian Ocean.
Theories about what happened range from the plane being hijacked to a cabin depressurization or power outage. There was no distress signal, no ransom demands, no evidence of technical failure or severe weather conditions.
Malaysian investigators cleared the passengers and crew in 2018, but did not rule out “unlawful interference.” Authorities said someone intentionally cut off communications and diverted the plane's flight direction.
Passengers came from many countries
There were 227 passengers on board MH370, including five small children, and 12 crew members. Most of the passengers were Chinese, but there were also citizens of the United States, Indonesia, France, Russia and other countries.
Those on board included two young Iranians traveling on stolen passports, a group of Chinese calligraphic artists, 20 employees of US technology firm Freescale Semiconductor, a stunt double for actor Jet Li and several families with young children. Many families have lost several members.
The largest underwater search in history
Search operations began in the South China Sea between Malaysia and Vietnam, then spread to the Andaman Sea and the southern Indian Ocean.
Australia, Malaysia and China coordinated the largest underwater search in history, covering approximately 120,000 square kilometers (46,000 square miles) of seafloor off western Australia. Airplanes, sonar-equipped ships and robotic submarines scoured the ocean for signs of the plane.
Signals believed to be coming from the plane's black box turned out to be from other sources, and no debris was found. The first confirmed fragment was a flaperon discovered on Reunion Island in July 2015, with additional fragments later found along the east coast of Africa. The search was suspended in January 2017.
In 2018, US marine robotics company Ocean Infinity resumed the hunt under a no-find-no-fee agreement, focusing on areas identified through debris drift surveys, but it was unsuccessful.
Detection problem remains
One of the reasons why such an extensive search has turned up no clues is that no one knows exactly where to look. The Indian Ocean is the world's third largest and the search was conducted in a challenging area where searchers faced poor weather and an average depth of about 4 kilometers (2.5 miles).
Airplanes disappearing in the deep sea are not common, but when they do, their remains can be very difficult to find. Dozens of planes have gone missing over the past 50 years, according to the Aviation Safety Network.
American company resumes search
In March, the Malaysian government greenlit another “no find, no fee” contract with Ocean Infinity, which will see the resumption of seabed search operations in a new 15,000 square kilometers (5,800 square miles) area of the ocean. Ocean Infinity will pay $70 million only if the wreckage is found.
However, in April the search was suspended due to bad weather. The government said on Wednesday that Ocean Infinity would resume the search intermittently from Dec. 30 for a total of 55 days in targeted areas believed to have the greatest likelihood of finding the missing plane.
It is unclear whether the company has new evidence of the plane's location. The company said it will use new technology and collaborate with many experts to analyze data and narrow the search to the most likely site.
