"narrator:" "there are global phenomena that science cannot explain -- true stories that defy rational explanation." "in the heavily trafficked skies of mexico city, a pilot encounters a trio of unidentified crafts." "first, they take control of his plane then ram it head-on." "can he warn those on the ground of impending danger, or will he crash trying?" "de los santos:" "mayday!" "mayday!" "mayday!" "narrator:" "in the united states, a man mysteriously burns to a cinder... this fire originated and stopped at the body." "...while others suddenly find themselves engulfed in flame." "the doctor said this burned from the inside out." "narrator:" "a series of careless mishaps?" "or is there a culprit deep within the human body, a ticking time bomb ready to explode?" "if you let a spark off, it can almost explode in your face." "i have no doubt that in the future this could happen again." "narrator: new investigations question unexplained happenings and otherworldly events." "woman:" "what is th-- oh, man!" "it's hovering!" "it's not an aircraft!" "narrator: firsthand testimony and fresh evidence build new possibilities." "man: never seen anything like that in my life." "and it just disappeared into thin air." "it wasn't from this planet." "my arms were just on fire." "narrator: rethink everything you think you know. captions paid for by discovery communications" "mexico city." "almost 9 million people call this place home, and every day, more than 100,000 planes take off and land." "but few flights have been as unforgettable and as mysterious as that of pilot carlos de los santos." "his dramatic encounter has baffled aviation experts for over a quarter-century." "what did carlos see that day that almost caused him to crash?" "did a trio of alien crafts take control of his plane for 18 terrifying minutes?" "it's a... very special experience for me." "man: yes, i'm sure." "i'm sure it is." "may 3, 1975." "pilot carlos de los santos has just flown a group of engineers to a tiny city along the pacific coast." "before taking off on his return flight back, he safety-checks his piper comanche plane." "[ engine turns over ]" "the first 40 miles unfold without incident." "interpreter: the weather conditions were very good." "the plane was in perfect condition." "narrator: but as carlos cruises over the clouds, an uneasy feeling envelops him." "is he being watched?" "interpreter:" "everything was normal, but i felt i was being observed, so i turned." "i discovered that on the top of the wing, there was an object heading towards me." "i thought to myself, quot;dear lord, what is this i'm seeing?" "it's right there.quot;" "in a matter of three to four seconds, i experienced the exact same feeling i had on the left side now on my right side." "it was a second object." "now i'm getting really nervous." "narrator: according to carlos, two gray objects, each about 13 feet in diameter with a small cockpit or windshield, are flanking his aircraft." "interpreter:" "quot;what on earth is this?" "quot;" "narrator:" "four seconds later, a third object appears in front of the plane, heading straight for carlos." "interpreter:" "now i'm really scared that it was going to hit the airplane." "i attempted to dodge it by pushing the control wheel forward." "narrator: but the control wheel won't engage." "carlos is terrified." "who or what is overriding his plane?" "at that moment, i had lost all control over the aircraft." "the third object managed to avoid the propeller and disappeared beneath the cockpit." "i heard a terrifying blow." "narrator: the object seems to hit the underside of his plane, but carlos is unable to check for damage." "the aircraft is now completely out of control." "interpreter:" "i had no idea what was going on." "three objects were flying around me." "at that point, i was terrified." "i needed to call for help." "narrator:" "carlos makes an emergency call to mexico city airport." "this is the actual recording of that call, the first time it has ever been broadcast on american television." "interpreter:" "i was absolutely terrified." "but more importantly, i had absolutely no control over the aircraft." "three ufos are surrounding the plane." "interpreter: i'd never received a call like that." "we heard a mayday emergency call." "the voice was very stressed and almost shouting." "we were all concerned." "the call unnerved us all." "narrator: before carlos can fully explain his situation, the plane starts to dramatically change course." "interpreter: all of a sudden, the airplane started to ascend without my input." "narrator: carlos can do nothing but watch in horror as the altitude meter rises ever higher." "interpreter: 10,100. 10,200." "10,300. 10,400. 10,500." "who knows where to?" "who is it?" "who is coming?" "who are they?" "what do they want?" "narrator: the plane creeps past 15,000 feet." "carlos is in trouble." "his small plane could easily stall." "interpreter: i was only around 20 years old at the time." "at the time, i was thinking about myself, my parents, and family." "i was in an awful state." "i was a nervous wreck." "that's a pilot's worst nightmare." "narrator: but just as carlos thinks the plane is about to fall out of the sky, the strange objects fly off as quickly as they arrived." "interpreter:" "i tried to turn and realized i had regained control of the aircraft." "narrator: carlos immediately starts to lower his altitude and heads toward the haze of mexico city on the horizon." "interpreter: i was worried the objects would come back." "i tried to descend as fast as possible." "i was eager to land." "narrator: but carlos' ordeal is far from over." "the cockpit lights indicate that the landing gear cannot be locked." "interpreter:" "when the third object had struck the bottom of the fuselage, it may have damaged the landing gear." "narrator:" "carlos now has no choice but to keep descending and prepare for a crash landing." "narrator:" "in the skies over mexico city, terrified pilot carlos de los santos finds himself surrounded by three unidentified flying objects." "after apparently taking control of his plane, they suddenly fly off." "carlos regains control of his aircraft but, crucially, not the landing gear." "interpreter: the third object hit the bottom of the plane." "the landing gear was damaged." "the three green l.e.d. lights were flickering, which indicated the landing gear had been deployed." "however, this didn't mean it was secure." "narrator: the control tower prepares for a crash landing." "interpreter:" "they were very concerned because there's always the risk that if you land without the landing gear deployed properly, it may cause a spark that would ignite the fuel tank and blow up the plane." "narrator:" "air-traffic controllers cannot risk injuring others, so they take drastic measures." "mexico's busiest airport must be shut down immediately." "interpreter:" "i was desperate by then." "narrator: carlos is instructed to land as safely as he can, so he chooses a grass strip between the runways away from other traffic." "interpreter: my only concern was to land safely." "i was crying." "narrator: but for reasons that remain a mystery, the landing gear suddenly starts to work again." "interpreter: i opened the door, left the engine on, and rushed off the plane." "the plane is okay. you are okay." "everything is okay." "narrator: once carlos' story about the three ufos makes it way into the news, he is taken to the airport's aviation services center for assessment." "interpreter: we arrived at the aviation services." "they started questioning me." "quot;what happened?" "quot;" "how am i feeling?" "[ monitor beeping ] they thought i might have been drunk, drugged, or starving." "[ inhales deeply ] narrator:" "conducting the examination is dr. luis amezcua." "interpreter:" "we did a complete checkup, as was usual with pilots." "we did an audio test, checked his vision, cardiogram." "narrator:" "blood tests reveal that carlos is not under the influence of alcohol or drugs." "one of the conditions that could explain what carlos saw is oxygen deficiency." "this leaves no trace." "clinically referred to as hypoxia, symptoms can include hallucinations." "hypoxia can be caused by high altitudes." "did the rapid ascent cause carlos to see things?" "interpreter: there are four stages to hypoxia." "the first one presents itself up to 10,000 feet." "at this stage, the healthy individual will feel no symptoms." "the second stage occurs between 12,000 and 15,000 feet." "that's when the body starts to become aware of the lack of oxygen." "breathing becomes faster, and hyperventilation begins." "narrator: but carlos claims he first saw the objects before the climb, at 10,000 feet, well below the altitude that would trigger hallucinations." "carlos' medical examinations rule out drugs and alcohol, and hallucinations were unlikely." "dr. richard haines was a research scientist at nasa for 20 years and is now chief scientist at narcap, the national aviation reporting center for anomalous phenomena." "dr. haines soon discovers that carlos is not the only eyewitness to the day's strange events." "julio diaz had his eyes fixed on the radar screen during his conversation with carlos." "interpreter:" "in 26 years of work, i've never had another experience like this." "to this day, it was a unique experience that i cannot explain." "narrator: what julio sees deepens the mystery around carlos' encounter in the skies over mexico city." "there was no doubt there was another object flying in that area." "narrator:" "pilot carlos de los santos claims he encounters three mysterious flying objects as he flies a small plane to mexico city." "but without evidence, it's easy to dismiss his story as the imaginings of an overstressed aviator." "julio diaz was the air-traffic controller on duty that day." "until now, he has refused to speak publicly of what he witnessed that day." "interpreter: i was sitting at the radar terminal when the pilot radioed." "he was located 48 miles south of mexico city airport, and he said he had been surrounded by some unidentified objects." "when the plane was about 15 miles from mexico city airport, we saw another blip right next to the plane." "there was no doubt there was another object flying in that area." "narrator: no other airplanes are registered as being in carlos' flight path." "diaz and the air-traffic controllers reach the same conclusion -- carlos is telling the truth." "interpreter:" "we figured it was the ufos that were being reported." "we all began to think of the possibility it was true." "this is important testimony." "and, to me, it's particularly important because it's confirmation of a physical nature." "it's radar confirmation." "and so it provides independent support for carlos' story." "narrator: but just because it's not registered doesn't mean it's from another world." "could it be a military plane flying under a veil of secrecy?" "while it's possible, julio dismisses this theory based on the curious way the craft moves." "interpreter:" "what really got our attention and concerned us even more was that it made a sharp 270-degree left turn in a radius of only 3 to 4 miles." "narrator: this is an exceptional maneuver for any aircraft and one that no known commercial plane of the time could accomplish." "interpreter: something that's never been seen before by me or my colleagues." "narrator: haines is not yet willing to dismiss the idea that the crafts are of human origin." "he visits carlos to get more information." "well, we're faced with a real mystery here." "what could these three objects have been?" "and it's been suggested they might be unmanned aerial vehicles." "sometimes they're called drones." "this sketch that you made in 1975 shows me a long oval, yes?" "narrator: investigators always have to consider experimental military aircraft before categorizing something as truly unidentified." "a significant percentage of these things are actually classified military aircraft." "for example, the u.s. stealth bomber -- if you'd seen this large, black, triangular-shaped aircraft before people knew about the stealth bomber, you might think, quot;wow. i've seen a ufo.quot;" "narrator:" "from carlos' eyewitness account and the objects' unique agility, dr. haines is forced to come to a controversial conclusion." "the objects carlos encountered are not man-made." "we didn't have drones in 1975 that had that kind of capability of very high-speed, controlled turns, and the navigation and guidance required to maintain a close position near another airplane in flight." "that takes very high computational power." "narrator: there are thousands of similar reports." "curiously, many of them come from latin america." "one contentious theory attempts to explain this, and the clue comes from carlos' testimony." "he stated that the objects flew off toward mount popocatépetl, an active volcano southeast of the city." "in recent years, this mountain has developed a colorful reputation." "ufo enthusiasts carlos guzman and alfonso salazar have noted strange sightings near this volcano for over 20 years." "on march 12, 2013, ufo watchers capture on video a mysterious object coming out of it." "guzman and salazar believe aliens use the electromagnetic forces on our planet to power their spaceships." "interpreter:" "it stands to reason that these ufos would tend to go for volcanoes, where a lot of electromagnetic activity exists." "the two men also assert that many south american governments are actively collecting data on ufo sightings along the andes." "the brazilian ufologist a.j. gevaerd believes this information is deliberately hidden." "many of the governments have been aware of the ufo phenomena for decades and have been investigating during this time." "all governments in the world are hiding information, something that we cannot explain to the society or, worse, that we cannot control." "it's better to say that it doesn't exist." "narrator: can there be any truth to a multinational cover-up?" "according to carlos, the answer is quot;yes.quot;" "interpreter:" "two weeks after my experience, i was overtaken by a black car." "it forced me to stop." "[ tires screech ] two people got out from the car." "they were dressed in black." "one of them came up and said to me, in a robotic voice, quot;stop talking about this." "don't say anymore.quot;" "i got scared." "i didn't say a word." "they went back to their cars and left." "[ tires screech ] i was scared for my family." "i didn't want to have anymore to do with it." "narrator: carlos was so terrified by these threats that he didn't talk about his experience for over 30 years." "so, what did happen to him in the air that day in may 1975?" "doctors discounted various medical conditions, and a hoax has been ruled out by many." "[ monitor beeping ] i don't believe what carlos saw was a hoax." "i don't believe it was a hallucination." "and i don't believe it was a drone." "narrator: radar sightings back up carlos' claim that there was something hovering near his aircraft." "diaz's interpreter:" "something like it has never been seen before by my colleagues or myself." "haines: so, what does that leave us with?" "an unexplained phenomenon." "interpreter: after all these years, without a doubt, i do believe that there were unidentified flying objects." "interpreter:" "there is a lot of evidence now that we are not alone in our solar system and the universe." "in a way, it would be selfish of us to think that we are alone, that we are the only ones, and that we are the only intelligent life in the universe." "narrator: 1,400 miles away, an alarming death startles investigators... there was nothing burnt around the body." "narrator: ...while another man lives to tell a similar tale." "baker: the doctor was completely baffled, and he said, quot;this burned from the inside out.quot;" "narrator: can science find the cause before it happens again?" "in the american midwest, a man dies in a flash fire." "on average, eight people burn to death in the u.s. every day, so the situation is not unusual... except for one mysterious detail." "why is he completely reduced to ash, but everything around him remains untouched?" "investigators rule out homicide today after a bizarre death in sequoyah county." "investigators say other parts of the house didn't have fire damage, and there were no signs of struggle." "it's very unusual, and it's bizarre, and i can't explain it." "narrator:" "the fire is ruled a mystery, and the official investigation ends." "but locals are not ready to close the books on this curious case." "they invite paranormal investigator larry arnold to come to sequoyah county." "arnold leads an organization called parascience international and has published books and articles on spontaneous human combustion." "can he uncover the answer?" "we're eager to learn more about this case because it sounds very fascinating, very mysterious, and presently quite unexplained." "narrator:" "after a mysterious fire, paranormal investigator larry arnold is questioning witnesses." "he begins by interviewing the local sheriff, ron lockhart." "lockhart has investigated arson cases for over 20 years." "but he's never seen anything like this." "lockhart: it was obvious that something bizarre had happened here." "that was a very unusual fire scene." "normally, you find burned bodies in a house that's basically burned down on top of them." "and normally, they're not as damaged as bad as this body was damaged." "rick russell is the local fire chief." "he, too, is baffled." "i arrived on scene at 10:51 a.m." "i noticed when i pulled up we only had a slight amount of smoke coming from the residence, no flame." "[ camera shutter clicking ] the thing that really surprised me was the " "there was nothing burnt around the body." "the refrigerator just inches form the body, plastic handle on the refrigerator door -- no melting." "plastic handle on the cooking range -- no melting." "trash bag laying just inches from the body -- it wasn't wrinkled from heat." "this fire originated and stopped at the body." "[ camera shutter clicking ] narrator:" "from the evidence at the scene, it appears that it was the body alone that was on fire." "russell concludes there was no external source, such as an explosion caused by gasoline." "i would rule against a flashover type because i think we would have had more evidence of burning." "the ceiling area, even the stove and the refrigerator should have shown signs if we had an explosion-type fire." "everyone who attends the scene is mystified." "how did this man die so brutally when everything else is intact?" "larry arnold believes it has the hallmarks of a highly debatable phenomenon -- spontaneous human combustion." "it's an extraordinary phenomenon." "it's extremely difficult to investigate." "lockhart: it was bizarre because everything that was mentioned, as far as the explanation and the characteristic of spontaneous human combustion, you know, we can't rule that out." "narrator: the phenomenon has mystified and divided opinion for over 300 years." "so, is it based on science or legend?" "since the first recorded case in 1641, over 200 incidents have been reported around the world from australia to the u.s." "in 1986, a retired firefighter mysteriously burned to death in his own apartment in crown point, new york." "in 2011, an elderly man who burned to death in galway, ireland, made headlines when the coroner gave a verdict of spontaneous human combustion, also known as quot;shc.quot;" "yet many dispute that it's a real phenomenon at all." "science investigator joe nickell is skeptical." "in 1984, he undertook a two-year research project studying 30 historical cases of alleged shc." "science cannot find any mechanism by which the human body can burst into flame." "and all such scenarios that attempt to explain how the body could combust are just so much science fiction and pseudoscience and nonsense." "narrator: investigator larry arnold disagrees." "he thinks spontaneous human combustion is a genuine anomaly that needs further study." "it's easy for academicians to generally dismiss shc because it belies common sense." "the body is 70% to 80% water." "it's like trying to ignite a swimming pool." "that's where the mystery, that's where the unexplained nature of these fires comes into play." "narrator:" "but could the answer be hidden deep within our own bodies?" "is there some trigger inside our fat cells that can spark at any time and reduce us to ash?" "[ sirens wail ] narrator:" "in a typical house fire, the cause of ignition is easily identifiable, and the remains of a human body are recognizable." "except in severe cases, the internal organs and the skeleton tend to be intact." "but the fatality larry arnold is investigating looks very different." "here, the body has burned to a cinder, yet the surroundings are virtually untouched." "one possible explanation is called the wick effect, and there's nothing spontaneous about it." "could this be what killed the man in oklahoma?" "arnold arranges a test to find out." "arnold: what we're going to do in this burn chamber today is attempt to replicate or duplicate the wick effect, which is what naysayers of spontaneous human combustion cases say is the explanation for wholly immolated human beings." "narrator:" "according to the wick effect, the fat content of the human body fuels the fatal fire." "a 168-pound male has around 30 pounds of fat." "when burned, this fat releases around 105,000 calories of energy, equal to three gallons of gasoline." "this is enough to engulf an average car, but can it burn a body?" "larry uses a hunk of fatty meat to replicate the event." "arnold: we have a ham shank here, containing bone fragment." "pig does burn very similar to human flesh, so it's an appropriate stand-in." "we're going to wrap it in cloth." "narrator: at least 2,000 degrees fahrenheit is required to reduce a body to ash." "at regular intervals, larry measures the temperature." "yep, we're already at 437 degrees and climbing." "narrator: after 15 minutes, the cloth is charred black, and the burning has stopped." "but what about the meat?" "arnold: the meat hasn't even been singed, let alone charred to dry powder." "the wick effect does not work to explain whole-body human immolations." "the highest temperature we measured here was just under 700 degrees fahrenheit at the height of combustion." "in a crematorium, by comparison, the cadaver is exposed to temperatures of about 2,400 degrees fahrenheit for an hour and a half to two hours." "narrator:" "larry's test reached a temperature of 518 degrees." "to put that in perspective, even a crematorium incinerator burning at 2,400 degrees fahrenheit is unable to reduce a body to ash." "after cremation, the bones are ground up before the remains are placed in an urn." "arnold: whatever burned the human remains in oklahoma, we submit, cannot be explained by the wick effect." "narrator: for arnold, the wick effect doesn't offer a plausible explanation for these mysterious deaths." "and there's something even more remarkable about this phenomenon." "some have actually lived to tell the tale of what happened to them." "frank baker is a decorated vietnam war veteran with two purple hearts and a medal for gallantry." "but his most terrifying brush with death was not on any battlefield." "it was in vermont in june of 1985." "we were getting ready for fishing." "we were sitting on the couch the day before the derby." "everything was great." "pete was sitting next to me." "we were having one hell of a time, and all of a sudden " "willey: it was the damnedest thing i've ever seen." "frank was freaking out and making me freak out." "[ sighs ] i was in sheer panic." "all i could do was try to fight it." "i was petrified." "i had no idea what was taking place with my body. none." "narrator: pete and frank managed to extinguish the flames and get to a doctor." "baker: the doctor was completely baffled, and he said, quot;" "looking at it, frank, this burned from the inside out.quot;" "and he said, quot;i've never, ever seen anything like this.quot;" "frank was nowhere near any source of heat or flame." "i wasn't smoking." "there were no flames around." "there was no lights on, no microwaves." "all that was coming in was the sun from the far end of the house when this happened." "narrator:" "frank's story doesn't end there." "it's happened more than once." "baker:" "we were going fishing." "everything was great." "and then " "all of a sudden, i started screaming at the top of my lungs." "my arms were just on fire." "narrator: once more, pete manages to put out the flames and save frank's life." "i ain't never seen anything in my lifetime such as the things i see that happened to frank." "narrator:" "today, years later, the damage to his skin has largely healed." "baker: the scarring has had 15 years to heal, and it just settled back down." "narrator: but the psychological scars remain." "i have no doubt that in the future or at any time this could happen again." "arnold: frank baker appears to fit all the criteria for survival of partial spontaneous human combustion, and he's had to deal with it." "he's had to come to terms with something that was said to be impossible, something that could not happen." "narrator:" "but recent research undertaken in cambridge, england, might offer new insight into the aberration." "professor brian ford is a leading independent researcher in cell biology." "he believes he's identified a substance that could solve the puzzle, something so volatile, it can ignite with just an invisible spark, like the static from a sweater." "it will set fire to the bottle, and it can almost explode in your face." "narrator:" "could ford's theory have finally zeroed in on the cause?" "are there chemicals in the human body so dangerous, they act like gasoline waiting for a match?" "narrator: for centuries, the terrifying enigma of spontaneous human combustion has baffled researchers across the globe." "now, in cambridge, england, professor brian ford has developed a theory that may explain it." "ford: i set out to search for a compound in the body that could burst into flame." "and although we often overlook the fact, human bodies produce acetone." "narrator: acetone, which is generally used as nail-varnish remover, is highly flammable with explosive vapors." "ford: all living cells produce acetone, but when you're ill, the level of acetone can go up." "narrator: it's this rise in acetone levels during illness that professor ford believes can be deadly." "acetone behaves a little bit like gasoline does." "if you let a spark off where there is the vapor of acetone, it will set fire to the bottle, and it can almost explode in your face." "narrator: the smallest spark, invisible to the naked eye, can ignite acetone." "for professor ford, this is the key to why the combustion appears spontaneous." "we know that things, like a spark from static -- you can even comb your hair and see sparks in the dark." "the mystery is, how does the person themselves become flammable?" "and of course, if they've got acetone in their tissues, that might convert a person from being incombustible into being something that burns like a rocket." "narrator: professor ford conducts a colorful experiment to test this theory." "he begins by making a scale-model human figurine out of pork and dressing it in miniature clothes." "it's then soaked in acetone so that the cells become saturated." "so, let's see." "what i believe happens in spontaneous human combustion is that the combination between fat and acetone becomes highly inflammable, and that is why, in a case like this, you see not just that you end up with a barbecued person" "but that the body is destroyed by the heat energy released from within the victim's tissues." "and that is what makes this into such a tragic, terrifying, appalling way to die." "narrator: within half an hour, the model is reduced to ash." "but, for larry arnold, the experiment has a fatal flaw." "the downside we see with professor ford's attempts to replicate shc in the laboratory is that he uses a very high concentration of acetone, and we do not believe that a living person could be alive with the amount of acetone in the body" "that he requires for his experimentation." "we just don't find it attributable to many cases, if not all cases, of shc, certainly not the cases that have been witnessed and survived." "narrator:" "survivor frank baker has no idea of his acetone levels at the time, but he maintains that ill health is not the answer." "at the time the incidents took place, my health was in perfect shape." "there was nothing, absolutely nothing that could have triggered what happened." "the way i see it, it has to be something in our body, whether it's in our blood stream, whether it's atoms coming together that maybe shouldn't." "narrator: mainstream science remains wary of embracing instantaneous combustion." "too many unanswered questions linger." "but for people like baker, that's no reason to delay research." "until science took a hard look at almost anything, it was considered unexplained." "baker:" "these people that are dying -- it's not happening because they want to die." "so, you know, look into it, scientists." "have an open mind." "this is what we rely on science for -- for facts." "they don't have the facts, then look for them." "that's what you're there for, to try to help other people."