12 Years After MH370 Vanished, Searchers Were Out of Options. So the World’s Best Robots Went Looking for It.

On January 2, 2018, from the port city of Durban in eastern South Africa, a ship departed at dusk. This was no vessel outfitted for a nighttime pleasure cruise. In fact, it looked downright strange. Its hull was a shade of prison-jumpsuit orange. Its bow was adorned with a large, flat platform resembling a helipad. Antennas, some pointy, some contained in two white domes, covered its superstructure. A crane was mounted on the ship's stern. Belowdecks sat eight autonomous submersibles, each weighing about 4,000 pounds, or the equivalent of a Ford F-150. This ship was heading east, bound for a section of the southern Indian Ocean about 1,500 miles west of Australia. Its mission? To find the notorious Malaysia Airlines Flight 370.

When MH370 took off from Kuala Lumpur on March 8, 2014, shortly before 1 a.m. local time, there was no indication it wouldn't be a routine flight. But the Boeing 777-200ER never reached its destination, Beijing. Instead, after 39 minutes in the air, the jetliner disappeared from radar; about seven hours after that, it vanished altogether. Satellite communications analyzed afterward showed that MH370 had turned southward and continued on that course until it presumably exhausted its fuel supply and crashed in the Indian Ocean off the western seaboard of Australia.

An expansive search was quickly mounted, the largest ever for a missing plane. Some 60 ships and 50 aircraft from 26 countries participated, at a cost of more than $150 million. More than 46,000 square miles of Indian Ocean seabed were scanned over a three-year period.

But the plane was never located, and the question of MH370's whereabouts set off a freneticism rivaled perhaps only by the mystery of Amelia Earhart's fate on her final flight. In the decade-plus since the plane vanished, numerous and varied hypotheses have surfaced. The aircraft crashed somewhere else, some suggested. Others insisted the plane was shot out of the sky. So vexing was MH370's disappearance that it even spawned a Netflix docuseries in 2023. Still others contend that, without a doubt, MH370 is on the bottom of the southern Indian Ocean.

Which explains the odd-looking ship that set off on its easterly course in 2018. The craft, a Norwegian-built research vessel named Seabed Constructor , was leased to Ocean Infinity, a deep-sea exploration firm with offices in Europe, Canada, Australia, and the United States. The Malaysian government contracted the company on a no-find, no-fee basis to look for MH370—a mission that promised a reward of up to $70 million. Over several months, Ocean Infinity used its autonomous subs to scan a grid of 9,600 square miles just north of the location where the original underwater search took place. By May of that year, having found nothing, the company suspended its mission.

Bringing the story of Malaysia Airlines Flight 370 to a definitive close has been equal parts confounding and elusive. A fool's errand, one might say. But in spring 2025, the government of Malaysia again contracted the firm—now equipped with new vessels of its own design, as well as advanced underwater robots—to mount a fresh search for MH370. In taking up the search again, in one of the toughest marine environments in the world, Ocean Infinity would be risking money and its reputation in the process. What if, for the second time, it failed to find a debris field of MH370 under the waters of the southern Indian Ocean? What if the black boxes couldn't be located? What if we never get a definitive answer to how Malaysia Airlines Flight 370 went missing without a trace?

After its 12:42 a.m. takeoff from Kuala Lumpur, with 227 passengers and 10 flight attendants on board, Malaysia Airlines Flight 370 quickly reached its cruising altitude of 35,000 feet and steered toward Beijing. Flying the plane were first officer Fariq Abdul Hamid, 27, and pilot in command Zaharie Ahmad Shah, 53. For Hamid, this was his final training flight before becoming a fully certified pilot. He was in good hands. Zaharie (who was known by his first name) was one of the most senior captains at Malaysia Airlines. He also owned a sophisticated Microsoft flight simulator that he used frequently at home.

At 1:08 a.m., MH370 flew out over the Malaysian coastline, soaring above the South China Sea toward Vietnam. Just 11 minutes later, when the handoff from Kuala Lumpur controllers to Vietnam's air traffic jurisdiction was about to take place, air traffic control in Kuala Lumpur radioed MH370 one final time.

"Malaysian three-seven-zero, contact Ho Chi Minh one-two-zero-decimal-nine. Good night," they said.

"Good night. Malaysian three-seven-zero," came the reply from the cockpit.

Those were the last words ever heard from the plane.

Soon the Vietnamese controllers saw MH370 cross into its airspace. But then something unexpected happened. Air traffic relies on secondary radar, whereby a transponder on an airplane sends a signal that contains information identifying the plane and its cruising altitude. This flight, instead, disappeared entirely from air traffic radar at 1:21 a.m. It wasn't until four hours later, at around 5:30 a.m., that any sort of emergency response commenced.

The simple fact was that at 6:30 a.m. on March 8, MH370—carrying passengers from China, Malaysia, Indonesia, Taiwan, India, Australia, New Zealand, France, Canada, the U.S., Ukraine, Russia, Iran, and the Netherlands—should have landed in Beijing. It didn't.

Making sense of how an object as large as a Boeing 777 goes poof in the night is hard to fathom in our modern age. And for the human mind, which craves order and explanation, it is downright maddening—which might explain the bevy of individuals, with no connection to the flight whatsoever, who jumped in eager to provide answers. Over the many years since MH370's disappearance, a variety of theories emerged about what happened to the plane. One scenario involves MH370 traveling toward Diego Garcia, a small atoll in the Indian Ocean where the U.S. has an army base, before being shot down. Another scenario claims the plane landed in the jungles of Cambodia. Other theories as to what happened to the flight received major airtime in 2023 during Netflix's three-part docuseries MH370: The Plane That Disappeared . The plane, one person speculated, was hijacked by Russian agents and rerouted to Kazakhstan. Another person claimed the U.S. Air Force shot down MH370 over the South China Sea.

Whether the U.S. Air Force was really responsible was never seriously considered by Malaysia. But officials had suspected that the plane crashed in the South China Sea en route to Beijing. Accident investigators from Europe, Australia, and the U.S. teamed up with the Malaysian government and began searching the sea's surface for any floating debris. That search was called off in April 2014 when nothing was found.

Yet within a week after MH370 apparently flew off the map, another theory surfaced in the Wall Street Journal . The article contains, to this day, the most plausible and reasonable explanation, one agreed upon by experts in aviation, satellite communications, and government: MH370 continued flying for hours after it disappeared from radar, turned west, away from its expected destination in Beijing, and then southward, ultimately meeting its demise in the waters of the southern Indian Ocean.

After the article was published, the Malaysian government eventually admitted that the account was true—which meant it had carried on a pointless search in the South China Sea for weeks. (In a comprehensive article for The Atlantic written in 2019, the late author and pilot William Langewiesche noted that autocratic bureaucracies with government-owned airlines generally want bad press to go away. It would be better, in other words, not to solve the puzzle, but to make the matter fade into memory as quickly as possible.)

To arrive at such a conclusion, the WSJ relied on an analysis of technical data from Inmarsat, a company that provides satellite services on land, at sea, and in the air. Although MH370 disappeared from air traffic radar screens, a feat easily achieved by whomever was manning the cockpit controls, it continued to link up every so often to a geostationary Inmarsat satellite over the Indian Ocean. Called "handshakes," these linkups are electronic blips that, while tiny, yielded the most information about what happened to the plane. There were seven handshakes altogether: two that came automatically from the plane, and five others initiated automatically from an Inmarsat ground station in Perth, Australia.

The Inmarsat linkups provided two critical values. The first value is the burst timing offset, or BTO. It's a measure of the round-trip time it takes for a blip to go from a ground station to a satellite to (in this case) an aircraft, then back up to the satellite and back to the ground station. It's essentially the distance between the plane and the satellite, and that information gets processed as a series of rings, or arcs, of all possible locations. When it comes to MH370, the most important arc is the last one, the seventh, which the plane crossed at 8:19 a.m. Kuala Lumpur time. What's important to note is that the seventh arc contains two location possibilities: If MH370 turned north, it may have ended up in Kazakhstan. If it went south, its location is in the southern Indian Ocean.

Determining the direction comes down to the second value: burst frequency offset, or BFO. It shows the difference between the expected frequency from a transmitter and the frequency ultimately received. As Langewiesche explained, the BFO is "a measure of radio-frequency Doppler shifts associated with high-speed movement in relation to satellite position." Think about it and it makes sense: Neither planes nor satellites are stationary objects, so expected signals won't match signals that actually get transmitted between the two. (That's the Doppler effect, that change in frequency of radio waves.) Measuring BFO is a way to determine a plane's speed and heading. During their investigation into the satellite data, Inmarsat technicians in London picked up on a distortion in the BFO value that suggested MH370 turned south at 2:40 a.m. Further analysis showed that MH370 entered a steep descent, as much as 15,000 feet per minute, just before crossing the seventh arc, which presumably happened after the plane ran out of fuel and both of its engines failed. From there it would have plunged violently into the ocean and shattered into millions of confetti-like pieces, to use Langewiesche's analogy.

And it's the satellite data, too, that paints a picture of MH370's deviated flight path. Once the plane disappeared from secondary radar, it did an about-face over the South China Sea, flew back across Malaysia, over the Strait of Malacca separating Malaysia to the northeast and Indonesia to the southwest, and then, very suddenly, made a sharp turn to the southwest, away from the Andaman Sea to the west of Thailand. Accident investigators later determined that this turn was so tight there was no way the plane was still operating on autopilot. Someone was actively steering it.

What the satellite data doesn't explain is why this happened—or who might have been flying the plane. Was it a potential hijacker? The available evidence says no: Malaysian and Chinese investigators, aided by American FBI agents, ran background checks on all passengers and flight attendants and cleared them of suspicion.

That left the pilots. Fariq Abdul Hamid was a young man with a fresh career as a prestigious Malaysia Airlines pilot ahead of him. Meanwhile, pilot in command Zaharie Ahmad Shah was portrayed in official reports as "someone beyond reproach." Just a simple family man. Yet as Langewiesche discovered during his reporting in Malaysia, the official depiction of Zaharie did not align with the man's private life: His wife had moved out, and he was "often lonely and sad." He admitted to his own friends that he spent his off-hours "pacing empty rooms waiting for the days between flights to go by." Among aviation investigators, there was strong suspicion, Langewiesche wrote, that Zaharie was clinically depressed.

And then there's his flight simulator. Most times, Zaharie let simulated flights play out, from wheels up to wheels down. But a forensic investigation of his simulator showed that Zaharie had done a dry run of a flight profile that eerily mirrored MH370's final flight path. What's more, Langewiesche reported, "he advanced the flight manually in multiple stages, repeatedly jumping the flight forward and subtracting the fuel as necessary until it was gone."

Was it Zaharie? One of the pilot's lifelong friends, another Boeing 777 captain, told Langewiesche he believed it could have been. It's not like such an event is without precedent: In 1999, for example, the copilot of EgyptAir Flight 990 intentionally crashed the plane into the ocean just south of Nantucket, Massachusetts. In 2015, the copilot of a Germanwings airliner deliberately crashed that plane into the French Alps. In a report published in 2014, the Federal Aviation Administration cites eight different examples of pilot suicides. And surveys conducted of pilots show that 4 percent have thought about taking their own lives.

As the search pressed on over the years, a group of researchers called the Independent Group emerged, made up of engineers and satellite experts who had found one another online as they simultaneously researched the MH370 crash. One of them, an engineer from Virginia named Victor Iannello, was the person who analyzed Zaharie's simulated flight, coming to the conclusion that the simulation wasn't some random event, but rather a potentially pivotal clue as to what happened on MH370's final flight.

"Until MH370 is found and the reason for its disappearance is known, we will be bombarded with conspiracy theories, false leads, books, and movies which will provide nothing but conjecture," said Prahlad Shirsath three months after the crash. His wife, Kranti, had been on board. "We need to find the truth," he continued, "and ensure this never happens again."

Where is that truth? Perhaps at the bottom of the Indian Ocean, the suspected location of the flight's data recorder and cockpit voice recorder. Recovering the black boxes might help investigators resolve what happened to MH370. But we have to find them first.

The ocean is vast, and the ocean is scary. The deep ocean especially. Consider, for a moment, the possibility that we know more about Earth's immediate orbit than we know about its oceans. In space, more than 9,000 satellites roam. On Earth, barely one-quarter of the planet's oceans are mapped in any coherent way so as to make them discernible for underwater exploration.

In May 2014, the governments of Malaysia and China agreed that the Australians should lead the search for MH370, under the auspices of the Australian Transport Safety Bureau. Fugro, a Dutch firm, was contracted to do the work, with payment coming from Malaysia, China, and Australia. Given the satellite data that suggested splashdown on or about the seventh arc, an area of roughly 11,500 square miles across the arc was selected for exploration. This put the search area between 930 and 1,700 miles away from Australia's western coast.

"Unforgivable" is perhaps the best word for describing the conditions of the Indian Ocean where search efforts were concentrated. The area saw ripping winds as high as 50 miles an hour, sudden powerful storms marked by 30-foot-high swells, and dense rain and fog. These were the least ideal conditions for sending ships out to sea for long periods of time, far from the closest ports, in a search for the maritime equivalent of a needle in a haystack.

When the underwater search for the remains of MH370 finally kicked off, the depths of the southern Indian Ocean were a mystery. An impressive level of surveying was conducted between May and December of 2014—with further mapping through early 2017—to even understand the topography of the deep ocean floor in this part of the world. It had never been mapped before. Fugro deployed three ships: the Equator , equipped with a hull-mounted echo sounder (to measure depth); the Discovery , with side-scan sonar; and the Supporter , which deployed a single autonomous underwater vehicle with side scanners, sonar, and an echo sounder. In all, close to 275,000 square miles of the deep ocean was surveyed, an area much larger than the search zone but valuable nonetheless for understanding the terrain.

Ridges, peaks, valleys, even underwater volcanoes covered the seabed. Most concerning was a deep underwater canyon that sliced horizontally through the seventh arc, believed by some to be the area where the remains of MH370 would be found. Dubbed Broken Ridge, it was formed by tectonic plate shifts more than 40 million years ago. Its depths reached between 2,000 and 20,000 feet beneath the ocean's surface; sections of its topography were covered in sediment as thick as 1,000 feet.

"It's like trying to imagine the Rocky Mountains underwater," says Mike Exner, another member of the Independent Group. Exner is a retired entrepreneur from Colorado with a background in electrical engineering and satellite communications, having founded several of his own companies. He has also been a licensed pilot for more than 50 years. Exner was the person who studied Inmarsat data and civilian radar—primary radar scans resulting from simple pings about objects in the sky—to conclude that in MH370's final hours, a flight to the seventh arc would not have been possible if there had been some sort of computer glitch or other systems failure.

"All those turns had to be done manually," Exner says. "I think we're about 99 percent sure Zaharie did it." He adds that he can't be 100 percent sure but says that once you consider the backgrounds of his copilot, the cabin crew, and the passengers, many of the signs point to him.

For almost three years, Fugro's ships looked across areas on or near the seventh arc for any signs of the plane. Admittedly, there was a technological element working against them. Autonomous underwater vehicles have been game changers in underwater search and rescue, but they still come with certain drawbacks. Traditional radio waves with meaningful data rates don't penetrate seawater at even paltry depths of six inches. Communication from ship or shore to a vehicle relies instead on sound waves. But even those become useless once the vehicle is roughly five miles away from its launch point.

"You have more contact with the Mars rover than you do [with] . . . a deep survey vehicle," says J. Carl Hartsfield, director and senior program manager of the Oceanographic Systems Lab at the nonprofit Woods Hole Oceanographic Institution in Massachusetts.

So we humans have to place a great deal of trust in technology that we can't control once it gets out into the ocean. What's more, Fugro had only one autonomous underwater vehicle at its disposal, and its maximum diving depth was 13,000 feet, which meant it wasn't reaching the seabed most of the time. As the years went on, the search zone was expanded from the original 23,000 square miles to an area surpassing 46,000 square miles. But not a scrap of the plane was found, and on January 17, 2017, the Australian-led search was suspended, pending further evidence of the plane's location.

Could it be that MH370 really isn't near the seventh arc? Could it have ended up somewhere else? David Mearns, a marine scientist who has led several deep-ocean explorations, says there are only two ways to explain why any piece of the aircraft wasn't found underwater.

"One, they haven't looked in the right place. Or two, they've looked in the right place, but they missed it," he says. "Anybody who comes up with anything else doesn't know what they're talking about."

By the time Ocean Infinity arrived at the scene of the crash in January 2018, much more had been deduced about MH370's probable location. While the initial underwater search took place, an amateur campaign to search for debris from the missing plane began. At the center of this was Blaine Gibson, a Seattle-based lawyer with a penchant for wearing a fedora. (The connection to Indiana Jones isn't lost on him. By his own admission, Gibson is fascinated by mysteries and archaeology. According to him, he once went searching for the Ark of the Covenant, the gold-plated chest containing the tablets on which the Ten Commandments were inscribed.)

"I was astonished to learn that there was no organized search of beaches and shorelines," he says. "It always seemed to me that the first piece of debris from this plane was probably just going to be found washed to shore by someone walking on the beach."

He was right. In July 2015, a flaperon, an airfoil that attaches to a plane wing next to the flap, was discovered by a beach cleaning crew on the French island of Réunion, more than 3,500 miles west of Australia. A right wing flap was found on Pemba Island off the coast of Tanzania, in East Africa, in June 2016. And about four months earlier that same year, Gibson located a honeycomb object broken off from a plane's horizontal stabilizer with the words "No Step" written on it, a piece that was confirmed to be "almost certainly from MH370 by matching part number, stencil, paint, and composition," says Gibson. In all, more than 50 pieces of debris have been found so far, much of it on Africa's eastern coast. (The currents in the Southern Hemisphere move in a counterclockwise swirl: east to west when they're close to the equator; the opposite direction farther south.)

The significance of the physical evidence can't be overstated. It appears to confirm that the plane crashed in the southern Indian Ocean, that it shattered on impact, and that there should still be more debris left on the ocean floor. The discoveries also refined the search area: Drift analysis conducted by the University of Western Australia put the crash site at a latitude somewhere between 28.3 degrees south and 33.2 degrees south.

In other words, the evidence provided Ocean Infinity a tighter target. In 2018, Seabed Constructor started its search grid at about 35 degrees south and some 1,300 miles to the southwest of Australia's west coast. It was also better equipped this time, having brought eight autonomous free-swimming submersibles called HUGINs. These robot crafts, designed and manufactured by Norway-based Kongsberg Discovery, are able to reach depths of 20,000 feet. Each comes with a lithium-polymer battery pack weighing 660 pounds; that allows for around 60 hours of uninterrupted search time. Each is also equipped with a downward-pointing sonar system as well as side-mounted sonars to send out pings to objects on the ocean floor. Onboard magnetometers on every HUGIN can confirm whether a return ping indicates something metallic in nature.

Back in January 2018, The Economist reported that Seabed Constructor was "the most advanced civilian survey vessel," and predicted that if it couldn't find MH370, it was "likely that nothing will, and that the mystery of MH370 will remain unsolved." In May, Ocean Infinity turned back to port, having found nothing on the ocean floor.

That two underwater searches proved fruitless has led to differing views as to where, exactly, the plane landed in the southern Indian Ocean. Richard Godfrey, a retired British aerospace engineer and a founding member of the Independent Group, believes the plane is farther north on the seventh arc. His conclusion largely rests on an analysis he's conducted of data from WSPR, or Weak Signal Propagation Reporter. Amateur radio operators constantly send test signals and record the data that comes back. Godfrey says that when an aircraft flies through such a signal, it creates a disruption that can be used to track that craft. His results put MH370 inside an 18-mile circle at 29.128 degrees south latitude, approximately 970 miles west of Perth.

"It will only take one more search of this area," Godfrey told the BBC in 2024, "and we will find MH370."

Meanwhile, other research groups think differently. One contends MH370 is farther east of the seventh arc, in a 20,000-foot-deep hole that lies along the longitudinal line of Penang Island just off Malaysia's western coast. Two separate groups believe that MH370 did not dive into the ocean and shatter; they think MH370 came to a controlled, guided landing, and then sank. Part of their argument rests on anomalies in the BFO data, those radio-frequency Doppler shifts. The predicted BFO came in at a much higher frequency than what was observed, possibly indicating that initial thoughts of where the aircraft came to rest are wrong.

One of those pushing this interpretation is Vincent Lyne, a former researcher at the Institute for Marine and Antarctic Studies at the University of Tasmania. He laid out his argument in a paper published in December 2024 and called special attention to the two large-scale searches along the seventh arc.

"A significant positive outcome for ocean research was the huge volume of seafloor data collected across [about 46,000 square miles]," he wrote. "It still remains the most intensely mapped seafloor area of our planet. MH370 was simply not there!"

How these interpretations factored into Ocean Infinity's new search was unclear. The company is tight-lipped and declined an interview for this article, but CEO Oliver Plunkett did acknowledge Godfrey's WSPR research in a 2022 teleconference with relatives who lost people on Malaysia Airlines Flight 370.

If there's a new dispute over the fate of MH370, it rests largely on where the plane will be found in the southern Indian Ocean, and not that the plane is somewhere under the seas in that part of the world. Gibson, who discovered part of the plane's horizontal stabilizer, maintains that there's no way a controlled landing took place. He cites the more than 50 pieces of debris that have been recovered since MH370 went down. "It's not intact under water," he tells me.

Exner, for his part, thinks the WSPR data is no substitute for the Inmarsat satellite communications. "Focus strictly on the seventh arc between 32 and 36 degrees south latitude," he says. "[MH370 is] probably within 50 miles of that arc. Even though [Ocean Infinity] didn't find it in the first search, that doesn't mean it isn't there."

When Ocean Infinity ultimately resumed its quest for MH370, it was going back with even newer technology. In the time since its 2018 search, the company had built a fleet of more than 15 ships, ranging from vessels as short as 46 feet and as long as 282 feet. While small crews could climb aboard these ships, all of the vessels were nonetheless designed for remote operation from Ocean Infinity's control centers at company locations. Ocean Infinity had also developed a line of proprietary underwater autonomous vehicles and acquired additional HUGIN submersibles to aid in its efforts.

The company had also accrued a solid track record of successful searches. Just under six months after Ocean Infinity suspended its search for MH370 in 2018, it discovered the lost Argentine Navy submarine San Juan in the Atlantic Ocean. The following year, it located the remains of the South Korean supertanker Stellar Daisy , which sank in the South Atlantic in 2017. In 2024, Ocean Infinity discovered the wreck of a U.S. World War II destroyer, USS Stewart , that the U.S. Navy had sunk deliberately for target practice in the waters of the Pacific Ocean off San Francisco.

Despite all that, Ocean Infinity trawled the unforgiving waters of the southern Indian Ocean for a few days in March 2025 until rough seas forced it back to port. It resumed searching in late December 2025 and kept at it through January 23, 2026, before departing the search area empty-handed.

"The scale of the challenge both geographically and technologically is almost impossible to comprehend," said Ocean Infinity's Plunkett in a March 2026 press release. "If nothing else, we can say with confidence that it isn't where we looked. That matters—it brings clarity, and it will help those continuing to study the evidence refine their thinking and shape future search strategies."

Underwater searches, obviously, are not easy or cheap endeavors. When Air France Flight 447 bound for Paris from Rio de Janeiro crashed and sank in the Atlantic Ocean off the northeastern coast of Brazil in 2009, the search team that was dispatched knew where to look for the Airbus jet. And despite it resting at a depth of only about 13,000 feet, the searchers still took almost two years to find it.

Woods Hole Oceanographic Institution's Hartsfield, whose lab helped facilitate that search, can't remember the exact figures but estimates that the ships deployed in the search operate at a cost of around $65,000 a day. The Remus 6000 Autonomous Underwater Vehicle used to locate the Airbus cost about another $15,000 a day (in 2026 dollars).

"Although this phase of the search has concluded, our commitment has not," said Plunkett. "We're continuing to work with the Malaysian government in the hope of being able to return when circumstances allow." Ocean Infinity's current contract runs until June 2026, which means if it hasn't happened, it's unlikely that a new search will get underway this year.

But as technology continues to advance, maybe someday an armada of vessels will hit the rough seas near the seventh arc once again—probing the depths, scanning the seabed, sending sonar scans into the darkness—and unearth the newest blips of hope in this maddening unsolved mystery.

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