One of the most widely used and indeed still safest forms of travel is the airplane. Every year millions of people use passenger airliners to crisscross the globe to far-flung destinations. Although there are many things that could potentially go wrong on a flight, a fact thrust into the spotlight with terror attacks, one such danger one might not immediately consider is the chances of a plane and its passengers, sometimes hundreds of people, taking off and seemingly flying out of existence, to never be seen again; gone without a trace. Even more surprising than that this could possibly happen in this day and age of advanced tracking technology is the sobering frequency with which these strange vanishings happen, and how recent some of them are. Here we will look into some of the weirder and more compelling of these cases in which passenger aircraft have vanished without a trace, to fly off to mysterious final destinations unknown. Fasten your seatbelt and put your seats and trays up into their upright positions, because we’re going for a ride.

By far the most talked about and mysterious missing airliner in modern times has to be the strange saga of Malaysia Airlines Flight MH370. On 8 March 2014 at 00:41 local time, the Boeing 777-200ER took off from Kuala Lumpur International Airport, Malaysia, for a scheduled flight en route to Beijing Capital International Airport in China, carrying 227 multi-national passengers and 12 Malaysian crew. Conditions were clear and Flight MH370 was scheduled to land at Beijing on time at 6:30 AM. It would never arrive at its destination, and has become one of the most inexplicable and bizarre aircraft vanishings in aviation history.

Malaysian air traffic control received an odd message from the aircraft at 01:19 local time, as the plane was on its way over the South China Sea, when the co-pilot radioed: “Alright, good night.” It was a seemingly simple, routine message that would be the last anyone heard from the airliner again. Malaysian military tracked the plane as it began to veer wildly off course, turning sharply from its north-east course to face nearly due west, making its way over the Malay Peninsula until radar contact was lost somewhere over the Andaman Sea at 2:15. Satellite data has shown that the plane continued some time like this over the South Indian Ocean before disappearing for good. Neither Flight MH370, nor any of its passengers or crew, have been seen since.

The missing Flight MH370 provoked the most intense and costliest search operation ever launched in aviation history. A multinational effort began scouring the Gulf of Thailand and the South China Sea, looking for any sign of the plane yet they found absolutely nothing. The search, which was led mostly by Australia, was soon extended to include the Strait of Malacca and Andaman Sea, until the search operation was meticulously searching and combing through vast swaths of area, eventually spanning approximately 46,332 square miles of the southern Indian Ocean, both on the surface and below, and still no trace of the missing plane was found. It was thought at the time that the plane had perhaps been deliberately piloted off course before crashing in the South Indian Sea off of Australia, but there was no trace of a crash found anywhere and this was all speculation, and additionally nothing particularly suspicious was turned up in an analysis of the records of the pilots, crew, or passengers. Making the whole thing stranger still was that there had been no distress signal made from the plane, nor any mention of bad weather or technical problems before vanishing.

The search for the missing flight MH370 would end up stretching on for over two years, during which time only a scant few clues would show up. One confirmed piece of wreckage from the plane washed up in July of 2015 at Réunion Island in the Indian Ocean in the form of a flaperon, and several other small pieces and fragments thought to be from the doomed flight have turned up in Africa at Mozambique, Mauritius and South Africa, but the main wreckage has never been found. Other unconfirmed pieces of debris from the plane that have been claimed to have been found include various purses and bags, as well as a piece of metal with the words “NO STEP” written on it found on a remote island in Madagascar, but it is unclear if any of these things actually belonged to the passengers aboard Flight MH370 or if the metal indeed belonged to the missing plane.

The mysterious vanishing of Flight MH370 continues to baffle to this day, and it has spawned a wide range of theories as to what became of it. The leading theory is that the plane flew on autopilot for several hours before running out of fuel and crashing into the sea, but the reason why remains unknown. Of course there are those who disagree with this, and the list of ideas on the disappearance ranges from the rational, to the colorful, to the absurd.

An increasingly popular notion has been that the plane was not on autopilot at all, but rather was under deliberate pilot control, and that the plane was guided into the sea in a controlled glide long after fuel ran out, rather than crashing. This theory lends itself to the notion that terrorists had taken control of the plane, or that the pilot had intentionally doomed the flight for some unknown reason, and another weird detail supporting this is that is seems that the aircraft’s data transmission system and transponder had been deliberately switched off shortly before it diverted off course. The glide theory also means that if this is true, then the plane could have successfully managed to glide under manned control for an extended range well out of the designated search area instead of simply plummeting into the sea, meaning that search efforts might have been focusing on the wrong area all along.

One eerie clue that was found pointing to the pilot intentionally diverting the flight was found in the form of data discovered on a flight simulator at the home of the plane’s captain, Zaharie Ahmad Shah, which included a plotted flightpath over the Indian Ocean similar to what the plane had taken before vanishing, making it seem that this could be a case of a premeditated murder-suicide. Detractors have pointed out that there is no evidence that Shah had plotted the course on the simulator himself, and that this was just one potential course of many found on the device. For the most part, the controlled glide and rogue pilot murder-suicide theory has largely been dismissed by authorities but is popular with amateur sleuths and others looking into the mystery.

Other more colorful theories run the gamut from the odd to the downright bizarre. One is the idea that North Korea shot down or hijacked Flight MH370, or the idea the Russian president Vladimir Putin had the aircraft hijacked. Then there is the theory that the U.S. military itself shot down the plane with fighter jets when they became concerned that it had been hijacked and on its way to suicide bomb the military base on the Indian Ocean atoll of Diego Garcia, or that it was shot down accidentally in a military exercise. According to proponents of this theory, this explains the notorious lack of transparency, conflicting reports, and sluggish, poor release of information the Malaysian government and other authorities have shown throughout the investigation. Adding to this conspiracy theory is the idea that all of the debris from Flight MH 370 found so far has been faked.

Various other theories claim that this was part of some insurance fraud scam, that the Israelis hijacked it to carry out a terror attack to blame on Iran, that the plane was forced to land in Ukraine and stolen, that the CIA was involved somehow, that China hijacked the plane to capture spies onboard, and of course that it was abducted by aliens. To this day, we don’t really know what happened to Flight MH370, and it looks like we likely never will. It remains a profound aviation mystery that continues to baffle and incite speculation and debate.

Malaysian Airlines Flight MH3770, while a spectacular case, is not the first passenger aircraft to have seemingly vanished off of the face of the earth. In 1948 and 1949, British South American Airways had not one, but two passenger airliners go missing without a trace. The first was an Avro Tudor IV plane named the Star Tiger, registration G-AHNP, which took off on January 30, 1948 from Santa Maria in the Azores archipelago, where it had stopped off for refueling on a flight from London to Bermuda. The stopover was originally supposed to be just over an hour, but ended up lasting for nearly a full day due to poor weather conditions. On the morning of January 30, the plane took off despite heavy winds at the time, along with 25 passengers and 6 crew. It flew at a low altitude of 2,000 feet (610 m) so as to avoid the worst of the punishing winds and was guided by an Avro Lancastrian aircraft, which took off an hour earlier and kept the airliner updated on weather conditions ahead. The two aircraft maintained constant radio communication with each other at this point.

During the flight, it was noticed that heavy winds were slowly throwing the Star Tiger slightly off course, yet it was still committed to its destination of Bermuda, and the weather merely resulted in an adjustment to the estimated time of arrival. When the Lancastrian landed in Bermuda, the experienced pilot Frank Griffin had not encountered any particularly dangerous weather and expected that the Star Tiger would not be far behind. It would never arrive. The last transmission recorded for the airliner was a request for a radio bearing by the Star Tiger’s radio officer, Robert Tuck, which was given and acknowledged. Not long after this, the Bermuda radio operator tried to contact the plane again but were met with silence. Bermuda Approach Control similarly failed to contact the aircraft, and at no point was any distress call received. The Star Tiger had seemingly just flown off into oblivion, and an emergency was declared.

A search was mounted almost immediately, involving the US Air Force, airplanes, and ships, and efforts to locate the missing Star Tiger would continue for 5 days, yet not a trace or scrap of the airliner could be located. A full investigation was subsequently launched but there could be found no reason for why the plane could have crashed, as the crew had been very experienced, the weather deemed not to be bad enough to cause the plane to go down, and the aircraft itself had not been suffering any serious technical problems. Neither could the investigation come to any conclusion as to why the plane had just suddenly ceased radio communications and not given any distress signal. In the end, the inquiry would state:

In the complete absence of any reliable evidence as to either the nature or the cause of the accident of Star Tiger the Court has not been able to do more than suggest possibilities, none of which reaches the level even of probability. …. What happened in this case will never be known and the fate of Star Tiger must remain an unsolved mystery.

No trace of the Star Tiger or its passengers and crew has ever been found, not even a scrap, and indeed its disappearance is credited as being one of the cases that really helped fuel talk of the whole phenomenon of the Bermuda Triangle and launch it into the public consciousness. Everything from sudden sheering winds, to pilot error, to sabotage, to the fact that it was burning more fuel than usual in its low altitude flight, to aliens and inter-dimensional vortices have been proposed as the culprit behind the vanishing, but the fact is we will most probably never know for sure.

The very next year, British South American Airways lost yet another passenger airliner under mysterious circumstances, a disappearance which would also eerily occur in the so-called Bermuda Triangle. The passenger jet Star Ariel took off on January 17, 1949, nearly exactly a year after the ill fated Star Tiger, heading from Bermuda to Jamaica with 20 people on board. The Avro Tudor Mark IVB passenger liner, registration G-AGRE, had an experienced crew and weather conditions at the time were very clear and calm, yet immediately after a simple, routine location report from the plane, as it cruised at a normal, safe 18,000 feet, all radio contact simply ceased. Considering that weather conditions were clear, no distress signal was issued, and there was no sign of anything at all awry, it was as if the Star Ariel had simply blinked out of existence.

An extensive search was unable to locate any trace of the missing plane. Authorities investigating the strange disappearance of the Star Ariel could find no signs of technical difficulty or a crash caused by the weather, and it was deemed unlikely that the plane could have possibly run out of fuel considering the distance it had gone and the altitude it had been at. Investigators were at a loss as to what could be behind the mystery. No wreckage or evidence of what had become of the Star Ariel was ever found, and frustrated authorities ended up labelling the cause of the vanishing as simply unknown. The best guess anyone has come up with is that the plane met some sudden, catastrophic unknown fate, such as perhaps an explosion that occurred without warning, but this is pure speculation. Not a trace of the plane or its passengers or crew have ever been located.

Another mysterious vanishing aircraft would follow in June of 1950. On June 23, 1950, Northwest Orient Airlines Flight 2501 was approaching Lake Michigan at around midnight on its flight from New York to Seattle, with a stopover in Minneapolis. The DC-4 propliner was carrying 55 passengers and crew of 3 at the time, and was heading into rather stormy weather. The weather was so bad, in fact, that three other flights had turned around rather than risk entering the storm. When the flight was nearing Benton Harbor, Michigan, the captain made the sudden request to be allowed to significantly lower the aircraft’s altitude from 3,500 feet to 2,500 feet, but no reason for the request was given. Despite the storm, other planes were in the area at the time, and the airliner’s request was denied. The pilot calmly acknowledged this and this would be the aircraft’s last transmission.

Not long after this final message, locals claimed to have heard a loud, sputtering noise followed by a bright flash of light in the sky. In the ensuing search operation, authorities at first focused on an unexplained oil slick on the lake near Milwaukee but could find no trace of a plane. Some debris turned up near South Haven, Michigan, which consisted of some human remains, blankets with the Northwest logo emblazoned on them, and some foam cushioning from upholstery, and divers rushed to the area to scour the bottom but extremely low visibility made finding anything impossible. It is widely thought that the plane crashed and sank in Lake Michigan, but no further wreckage has ever been found, despite extensive sonar analysis of the bottom in the region of the crash that has turned up nothing but shipwrecks. At the time, this was considered to be the deadliest commercial airline accident in American history, and the cause of the apparent crash of Flight 2501 is still unknown.

The following year, on July 21, 1951, a Canadian Pacific Douglas DC-4 departed from Vancouver, Canada en route to Tokyo, Japan. It was the height of the Korean war, and the airliner, along with 31 passengers and 6 crew, were on their way to assist in airlift operations. The plane was approaching Anchorage Alaska for a refueling stop, about 90 minutes from arrival, when it checked in with its position. Then it simply vanished. Although weather conditions were rainy and icy at the time, the plane had reported no technical issues or problems in its last transmission. No trace of the aircraft has ever been found.

On March 16, 1962, Flying Tiger Line Flight 739 took off from Travis Air Force Base in California on a flight to Saigon, Vietnam. The Lockheed L-1049 Super Constellation propliner had been chartered by the US military and was in the process of transporting 93 American Army Rangers and 3 South Vietnamese military personnel. Also on board were 11 civilian crew members. The plane made a scheduled stopover in Guam, after which it continued on to its next stopover at Clark Air Base in the Philippines. 80 minutes into the flight, the pilot made a routine transmission of their location, which was given as about 280 miles west of Guam, and it was noted by operators that the radio contact was beset with heavy static. Weather conditions at the time were clear and calm. When further contact was attempted, the flight remained silent. It would never be seen or heard from again.

The subsequent search was one of the largest air and sea rescue operations in history, including aircraft and ships from the Navy, Air Force, Coast Guard, and Marines, and over 1,300 personnel, who scoured a total area of more than 200,000 square miles (520,000 km2) over 8 days without finding so much as a scrap of wreckage. The only clue as to what might have happened to Flight 739 was a report from a civilian Liberian oil tanker claiming to have seen an intense bright light in the sky followed by two descending fireballs near the plane’s estimated position about 500 miles (800 km) west of Guam approximately 90 minutes after its last transmission. The tanker reported that it had ventured to where the fireballs were estimated to have fallen but had found no sign of any floating wreckage or debris. It was thought that the tanker had possibly witnessed Flight 739 exploding in midair, but it was difficult to prove without a single trace of evidence.

The main theory was that the plane was the victim of sabotage, which would not have been unusual since one other Flying Tiger Line flight chartered by the military had crashed due to suspected sabotage in Alaska’s Aleutian Islands after departing from the same starting point, Travis Air Force Base, a mere 6 hours before Flight 739 had vanished. It was also claimed by officials of the airline that it was impossible for the Super-Constellation aircraft to experience a midair explosion under normal operating circumstances and that there had been nothing on board that could have caused such a catastrophic blast, further leading authorities to suspect some form of sabotage or terrorist act. However, with no wreckage recovered and indeed no sign of where it had gone, it was impossible to come to any conclusion as to the aircraft’s fate. No trace of neither the plane nor all of the passengers and crew has never been found.

A particularly weird disappearance of an airliner occurred in 2003 in Luanda, Angola. On May 25, 2003, at Quatro de Feveriro International Airport in Angola, shortly before sunset, a Boeing 727-233 with the tail number N844AA was boarded by mechanic Ben Charles Padilla and his hired helper Mikel Mutantu. Padilla had been hired to work on the decommissioned American Airlines plane to get it ready for its next flight, and had enlisted the help of Congolese Mutantu. The two were strictly mechanics, with neither of them possessing a commercial pilot’s license, and they definately had no clearance to enter the plane or its cockpit. It is unknown why the two suddenly got aboard the plane, but what is known is that it suddenly began an unauthorized taxiing down the runway with its engines revving.

Although it was sunset, the aircraft’s headlights were turned off and calls to the cockpit went unanswered. Furthermore, the plane was described as moving erratically, and its transponders had been deactivated. Although neither of the two men seen to have entered the plane were anywhere near qualified to fly it, it nevertheless taxied onto the runway and took off without clearance right in front of the bewildered air traffic control officers, and proceeded to head off southwest towards the Atlantic Ocean. All frantic efforts to contact the cockpit were met with silence until the plane disappeared from sight and for all intents and purposes from existence.

The fact that this incident occurred hot on the footsteps of the 9/11 terrorist attacks was serious cause for concern, and the FBI, CIA, and the U.S. Departments of State and Homeland Security were all over the investigation immediately in a desperate attempt to staunch what they felt could be another incoming similar terrorist attack. The attack never came, but neither did any evidence on just where in the world the missing plane had gone. An intensive 2-month search turned up no sign of it and theories on what had happened to it ran rampant.

One of the first ideas was that it had simply crashed not long after take-off, but there was no concrete evidence of this as no wreckage was ever found. Also going against this idea were the numerous unconfirmed sightings of the plane that cropped up after its disappearance. N844AA was allegedly seen in July of 2003 in Conakry, Guinea, and again in August that same year at Kankan Airport, Guinea, although these reports remain unsubstantiated and there is no hard evidence at all that the plane has been in any of these locations, or anywhere else at all for that matter.

Another theory is that the plane was stolen to be put on the black market, put to use by terrorists, converted to a freighter for fuel or drugs, or simply stripped for parts, but if this is the case then it seems unlikely Padilla and Mutantu could have been working alone. Not only did neither of them have the qualifications to fly such an aircraft, but a Boeing 727 is supposedly nearly impossible to fly without a highly trained crew of at least 3, so how did these two untrained mechanics make off with it? One idea could be that an unknown nefarious group was on the plane and kidnapped them along with their spoils, or that Padilla and Mutantu were working with them from the beginning.

Another theory holds that it was all a part of an insurance scam. At the time the aging plane had been sitting around the airstrip for months collecting dust and millions of dollars in back airport fees. Additionally, it was described as being old and rundown, with a faded, unpainted finish and all of the passenger seats removed, yet was still highly overvalued in its insurance. It seems possible that someone might have wanted to erase the plane to collect the insurance money and get it out of their hair. However, if this is true, then what happened to Padilla and Mutantu? Were they in on it and went off to live as fugitives or were they disappeared as surely as the plane was? Another theory still is that the plane was shot down by the Angolan military shortly after take-off and then covered up. In the end, no one knows where the missing N844AA or Padilla and Mutantu went, and it remains one of the largest aircraft to have ever vanished without a trace.

There are many questions presented by cases like these. It seems odd that in this day and age of advanced technology, of GPS systems and satellite tracking, that it should be possible to lose track of such large aircraft and have them vanish to never be seen again. How is it possible that these planes can just suddenly seemingly spontaneously cease to exist in modern times? One problem is that in many of these cases the aircraft’s transponders or tracking systems had been deactivated, either by accident or intentionally, which would make tracking much more difficult. Satellite tracking can also be problematic due to the sheer number of airliners in the air at any given time and the fact that some poorer countries fail to implement proper tracking technology due to costs. This is all exacerbated by the seemingly meager amount of manpower dedicated to focusing on keeping carful tabs on all planes, which mostly falls to the private sector and civilian aviation agencies. The government itself has been accused of not paying enough attention to missing civilian planes, even in the wake of the 9/11 terrorist attacks. One former intelligence officer who previously served in the once active top secret civilian aircraft tracking agency called SUDDEN SPIRIT said in a very enlightening article in Air and Space Magazine on the dark underbelly of missing planes :

The government has all this freaking expensive stuff—satellites and gadgets and shadowy operations—that collect all this secretive information. Almost none of it is focused on civil aviation. They’re focused on the same crap they’ve been focused on forever, which is foreign military capabilities. If you want to know about some foreign fighter jet, there are probably thousands of people focused on that. If you want to know [about] an airliner, there might be one guy in the whole government.

All of this, in combination with the often remote, difficult to access regions into which the aircraft often crash, would make finding missing airliners and debris difficult. If a plane crashes into the ocean or a large lake, deep water and murky visibility can make finding wreckage nearly impossible, and strong currents can serve to scatter debris far and wide. Perhaps when airliners are all equipped with the newer, more precise technology of ADS-B (Automatic Dependent Surveillance—Broadcast) transmitters, the number of instances of vanishing planes will be reduced, but even then the systems can possibly still be compromised, removed, or turned off, and for now we are still seeing planes fly off the face of the earth as in the case with Flight MH370. There is also the possibility that the planes can be stolen and either their identity concealed through removal of identifying marks and serial numbers to make them impossible to track, or simply being gutted for parts to dissolve into nothingness. This is actually rampant in many parts of the world, and these aircraft are commonly referred to as “ghost planes.”

Another question is just what happened to these planes in the first place? For some cases, it could be that they simply crashed due to pilot error or technical malfunctions, but in many cases the aircraft were manned by seasoned crew flying under calm conditions, with no sign of trouble and no distress transmissions issued, and yet they just simply vanished, sometimes right under the noses of air traffic control. Another possibility is that they were subjected to a sudden, violent event, such as a bomb or being shot down by hostile forces. This could explain the sudden lose of radio contact even in clear weather, but there is not always an explosion reported, and it would have to be a potent explosive force to so completely and suddenly destroy a large plane without any warning at all. Yet another scenario is that the planes have been hijacked and taken to locations unknown, yet in that case what happened to all of the passengers and crew aboard them and why haven’t they or the aircraft itself ever turned up? Let’s also not forget the other, spookier, no doubt less likely scenarios such as the mysterious forces such as the Bermuda Triangle, alien abduction, and inter-dimensional vortices.

So what is all of this? Terrorists? Storms? Pilot error or technical malfunctions? Aliens? Do these planes disappear because they have fallen where no one can find them? Because they were whisked away by nefarious agents and erased from existence? Or is it because mysterious forces beyond our comprehension have swallowed them up without a trace? Likely in the end there is no one culprit behind these vanishings, and there is probably a variety of factors at play depending on the case. In the absence of any recoverable evidence to analyze it is really hard to say, and often we are left just grasping at straws. The only thing we can say for certain is that, despite all of our technology and surveillance abilities, large passenger airliners can and still do go missing. Even now there are still those flights to nowhere, taking off and flying past the horizon and into the realm of great unsolved mysteries.