it was just an amazing heroic act. it's a big sky, until two planes end up in the same place. >> climb, climb. >> at the same time. 37,000 feet above the amazon, a corporate jet collides with a 737. >> every atom in my body i felt kind of implode. >> one mile above new york city, a dc-8 tears into the fuselage of a lockheed constellation. >> bang! i jumped up and i ran and i never looked back.

>> over san diego, a 727 slams into a cessna, and it's caught on film. >> i knew it was big. i knew it was bad. but we didn't know it was a plane crash. >> outside los angeles, a small plane crashes into a dc-9, decimating several homes below. >> it just smelled like death, like smoke and death. >> eyewitnesses and survivors tell their harrowing stories, and dramatic animations put you right there with the troubled aircraft. that big sky just got a lot smaller. ♪ "why planes crash: collision course." >> a new concept in air

transportation, the travail has been taken out of travel. >> when this short film about air travel was released by pan-am in 1958, flying was a special occasion. people got dressed up, meals were served on white linen. >> delicious food adds to the enjoyment. >> we all know that's changed. but an even more significant change is the increase in air traffic. flying over the u.s. in 1960, there would have been about 1,400 planes in the sky at any given time. today that number is more like 7,000. >> in 2011, we flew almost 3 billion people. we would fly about the population of the earth every 24 months or so, and it's expected to grow. >> with such increase in volume worldwide, it seemed there would be a greater risk of planes

colliding in the sky. but technology is more sophisticated than ever. so these types of accidents are actually less frequent than in the earlier days of passenger jet travel. that doesn't mean midair collisions don't happen anymore, because sometimes technology fails, and it's nearly impossible to eliminate human factors. in 2006, this plays out with catastrophic consequences for two planes flying over the amazon -- a boeing 737 and a private corporate jet. >> i had gone to brazil on an assignment for a magazine called "business jet traveler" to write about embraer, which is a big aircraft manufacturer near sao paulo. and when i was there, i ran into some guys from a long island

charter company who had just bought a brand new, $25 million airplane, a legacy 600, a real beauty, a midsize corporate jet. and they said, why don't you fly back with us? the plane has 13 seats and there were 6 empty seats. sure, okay, i'm in. and that turned out to be certainly the most fateful decision of my life. >> september 29th, 2006. 2:52 p.m. the legacy, tail number 600 x-ray lima takes off from san jose dos campos. destination, the city of manaus, nearly four hours to the northwest. air traffic control instructs the "legacy" to fly at 37,000 feet, where it levels off by 3:33 p.m. meanwhile, two minutes later, gol airlines flight 1907 departs manaus for the country's capital of brasilia in the south.

within a half hour, the boeing 737 reaches its cruising altitude, 37,000 feet. the 737 is heading southeast. the legacy is heading northwest. the two aircraft should be at different altitudes. instead, they're on a collision course. >> it was a beautiful day, puffy white clouds in the sky, nothing obscuring our view. we took off for what was to be a routine flight. we were flying with very competent pilots in a brand new airplane. what could be bad about that? >> both sets of pilots are in contact with air traffic control, operated by the brazilian air force. but starting at 4:02 p.m., northwest of brasilia, there's a problem. "the legacy's" radar data is no

longer being received by air traffic control. >> at some point during the flight, the transponder, which provides altitude information to the controller, inadvertently disappeared. >> a transponder is critical, not only to relay key information to air traffic control and nearby planes but also in order to enable tcas, the traffic alert and collision avoidance system, which warns pilots when another plane is too close. >> traffic, traffic. >> and advises preventive action. >> climb, climb. >> in addition to the missing transponder signal, which is preventing the "legacy" from sending its data, there's another problem, well-documented radio dead zones over the amazon. beginning at 4:26 p.m., air traffic control and the "legacy" pilots make several attempts to verbally communicate, all unsuccessful.

under normal circumstances, they would acknowledge each other's calls. >> brazilian air traffic control system in its overall shoddy performance had misprogrammed its own consoles, so it had given five radio frequents for the areas the pilots were in, four of which were in complete error, had nothing to do with that sector. unbelievable, right? but that's the way it was. >> even though they are cleared to fly at 37,000 feet, when one controller hands it off to another at end of his shift, he tells him incorrectly the plane's at 36,000 feet. in reality, the legacy and the 737 are at the same altitude, traveling at about 500 miles an hour apiece. that adds up to a closure or combined speed of about 1,000 miles per hour. >> you're talking a lot of energy with aircraft that weigh hundreds of thousands of pounds. so, when they do collide at that

high velocity, there is total, typically total destruction of the aircraft. >> by the time radio contact is made at 4:53 p.m., the connection is so bad, the "legacy" pilot and controller can't understand each other. the planes are closing in. >> everybody was sort of dosing or working. i hear and feel, bang! the loudest noise i ever heard. i was in vietnam and i've heard bombs, but just, bang! and every atom in my body i felt kind of implode. >> i've flown as a passenger a lot, and you go through all kinds of weather and all kinds of turbulence, and i've never felt an impact like this before. >> because of the angle at which the planes collide, the 737, though much larger, takes a far worse hit than "the legacy." >> one of the wings, which has a winglet on it, actually sliced

through the 737 wing. there's a lot of flight control systems that are damaged. it rendered the airplane incapacitated and uncontrollable. as the 737 went out of control, of course, the aerodynamic forces have caused it to actually start to break up in flight. >> everyone on board the "legacy" knows something bad has happened, but they don't know they've collided with another aircraft. they don't even know their plane is damaged until joe sharkey looks out his window. >> i opened my window shade and i looked out. and this is a sight i will simply never forget, because i'm looking at the wing and part of it is missing. and it's a jagged bit of metal. >> they need on the ground and they need on the ground in a hurry. they need the first available airport. coming up, 35 heart-stopping minutes in the air and a landing seared into this passenger's memory. >> it was just this moment of

absolute serenity where it dawned on us all, oh, we're probably about to die. you totaled your brand new car. nobody's hurt, but there will still be pain. it comes when your insurance company says they'll only pay three quarters of what it takes to replace it. what are you supposed to do? drive three quarters of a car? now if you had liberty mutual new car replacement, you'd get your whole car back. i guess they don't want you driving around on three wheels. smart. with liberty mutual new car replacement, we'll replace the full value of your car. see car insurance in a whole new light. liberty mual insurance. at ally bank, no branches equals great rates. it's a fact. kind of like grandkids equals free tech support. oh, look at you, so great to see you! none of this works. come on in. ...of fixodent plus adhesives. they help your denture hold strong more like natural teeth. and you can eat even tough food.

fixodent. strong more like natural teeth. fixodent and forget it. what do you do for a living? everyday experts... firefighter. i'm a police officer. i'm a e-m-t, actually. to talk about how some every day features... could help protect you in a collision. [crash] then we showed them how nissan can help you avoid a collision altogether. hey, you want to go for a ride? nissan's intelligent safety shield technologies. wi rear cross traffic alert. it worked, huh? blind spot warning. should i change lanes? no! woah. predictive forward collision warning and forward emergency brake, which could stop your car... for you. that's exactly how it happens. get to nissan's safety today event and save for a limited time with 0.9% financing for up to 72 months on altima, sentra, rogue and maxima. what'd you guys think?

it'll definitely help save lives. we might be out of a job. shop your local nissan store and choosenissan.com today. ♪

september 29th, 2006, seven miles above the brazilian amazon, a 737 collides with an embraer legacy. it's a devastating accident. the 737 is rendered uncontrollable and plummets toward the ground. but the "legacy" is still in flight. its left winglet down and stabilizer damaged. as the pilots struggle to fly the plane, no one on board knows there's been a midair collision. what they do know is they're in trouble. >> to think that you may not see your family or that they're going to read about you and see

about your death on tv and on the newspaper was, it was a horrible thought. >> i wrote a note to my wife and figured, well, maybe they'll find it. i said "i love you," "our time together has been golden," you know, i'm sorry i'm going to die. but you know, i said it in a way that was nice. >> like most plane crashes, a series of events, not just one, led to the collision over brazil. two planes fly straight toward each other after air traffic control put them at the same altitude. radio black holes over the amazon limit communication between controllers and the legacy pilots. and for nearly one hour before the collision, "the legacy's" transponder doesn't transmit. so, two controllers working back-to-back shifts don't receive its signals. >> a competent controller would spot that within two or three sweeps. there's a sweep every ten seconds. within 20 or 30 seconds.

this plane disappeared in that sense for 50 minutes, not 20 or 30 seconds. >> within three minutes of the impact, the transponder is reactivated. but the legacy is now compromised. it needs to land soon. >> it's the longest 35 minutes i've ever spent in my life, you know, wondering, were we going to make it down safely, wondering with every turn, would they lose control of the airplane. >> the closest runway is a military base, literally an airstrip in the middle of the jungle. as the pilots desperately try to get their plane there, it's a white-knuckle moment for everybody on board. >> we were within five minutes of not flying anymore. it was clear, i mean, the trees were coming closer and closer, and i thought, well, here we go. >> once safely on the ground, the passengers, still unaware

how they got into this situation, are happy to be alive. but hours later, they learn they've been involved in a midair collision with a 737, that the jet crashed in the jungle, and 154 people perished, and the mood quickly turns. >> i just sense the change in the environment, and i knew that we were now being treated like criminal suspects. >> following the crash, there are protests in brazil with relatives of victims demanding more information about the crash. writer joe sharkey says much of the anger turns toward the american survivors. >> crazy rumors were starting to fly in brazil. among them was that at the time of the accident, because i, the reporter, was on board, it was a brand new plane, the two american pilots were flying loop de loops to show the plane off

over the central amazon, causing the disaster. now, that's crazy. >> of course, when the plane's instruments were studied, it was clear that the plane had been steady as a rock at 37,000 feet. >> joe sharkey is held in brazil for two days. the pilots, joe lapore and jan paladino, are held for more than two months. when they are finally allowed to leave the country on december 9th, 2006, they receive a warm welcome back at their company headquarters in long island, new york. but the pilots' problems are far from over. nine months after the accident, the brazilian government indict the american pilots as well as four of its own air traffic controllers for exposing an aircraft to danger. the international aviation community has come out strongly against criminalizing accidents. >> we have to know what they were thinking, what decisions they were making, why they acted the way they did.

and if there's a fear of going to jail and that punitive action against them, then that's going to inhibit the information that we as investigators get. >> the criminalization of aircraft accident investigations is an impediment to safety. when you have situations where there is not a deliberate act, the key focus needs to be let's not have a reoccurrence of it. >> in may 2011, a federal judge in brazil acquits the "legacy" pilots of all charges but one, negligence for not monitoring their transponder. the final terms of the sentence are pending, but it seems unlikely the pilots will serve jail time. joel weiss, attorney for the pilots, says they were never at fault because the transponder was on. but then, without warning, his clients say, it went off or into standby mode. >> we have all kinds of

anecdotal evidence from all over the world, particularly in europe, of this transponder unit failing without any indication whatsoever in the cockpit that it had failed. >> components do fail. so, it's not that it's necessarily been turned to standby. it's a failure. >> in brazil, one air traffic controller described by the judge as unqualified and incompetent is acquitted. another controller is convicted of negligence. in its final report, brazil's ntsb equivalent acknowledges the failures of the brazilian controllers as well as the "legacy" pilots, stating that both parties should have become aware of the loss of radio communication far sooner than they did. in an e-mail, cenipa's press office states their investigation does not establish responsibility or guilt, but identifies the contributing factors with a primary objective being prevention.

if there's a lesson to be learned from this tragedy, it's that there will always be human factors that lead to accidents. >> but the lack of transponder information for a period of time from the embraer airplane, that created human factors issues with regard to situational and positional awareness for the air traffic controller. whether you're military or civilian, it's the human involvement, and it's the human error that starts these sequence of events. when we come back, more midair collisions over two of america's biggest cities. >> i jumped up and i ran and i never looked back. ♪ (music plays throughout) ♪ uh oh. what's up? ♪

♪ does nobody use a turn signal anymore? ♪ igoing to clean betteran electthan a manual. was he said sure...but don't get just any one. get one inspired by dentists, with a round brush head. go pro with oral-b.

oral-b's rounded brush head cups your teeth to break uplaque and rotates to sweep it away. and oral-b delivers a clinically proven superior clean versus sonicare diamondclean. my mouth feels super clean! oral-b. know you're getting a superior clean. i'm never going back to a manual brush. so strap yourselves in for action flo! small business edition. oh, no! i'm up to my neck in operating costs! i'll save the day! for plumbers and bakers and scapers of lawn, she's got customized coverage you can count on.

you chipped my birdbath! now you're gonna pay! not so fast! i cover more than just cars and trucks. ♪ action flo did somebody say "insurance"? children: flo! ♪ action flo cut! can i get a smoothie, please? ooh! they got smoothies? for me. ooh! they got smoothies? e.t. phone home. [ soft music ] when you find something you love, you can never get enough of it. change the way you experience tv with xfinity x1. before there was a modern air traffic control system, the burden of maintaining separation between commercial aircraft fell mainly on pilots. they kept their distance using what's called visual flight

rules, otherwise known as see and be seen. >> think of it as driving your car. you avoid traffic by seeing it and not putting your car where there's another car. the airplane works in visual flight rules the same way. >> see and be seen is a catastrophic failure in two deadly collisions between the same two airlines, twa and united. the first crash is over the grand canyon on june 30th, 1956. >> these two pilots were having to deviate around thunderstorms, build-ups that were occurring. you can't fly through them. so, they were deviating around them. they actually didn't know that when they came back around the back side of the clouds, the other aircraft was there. >> the united dc-7 and twa lockheed constellation or super connie collide at 21,000 feet. at the time, it's the deadliest accident in aviation history.

>> tragic aftermath of saturday's twa/united airlines crash, which claimed 128 lives. >> it was a watershed event. it was one of those accidents that we as a society said we're not going to have that anymore. >> the collision prompts the federal aviation act of 1958, which creates the faa, whose mission is to provide the safest, most efficient aerospace system in the world. unfortunately, change doesn't happen quickly enough. >> the wreckage went into the church, into the street and into the surrounding buildings, but i imagine that was about the first contact with the ground, the top of that garage. >> the pillar of fire church. >> yes. isn't that ironically named? >> it's a dreary december

morning in 1960 when twa and united have another catastrophic incident, this time over new york city. 10:25 a.m. air traffic control alters the route of united flight a-26, a dc-8, shaving 11 miles off its path to new york's laguardia airport. 10:30 a.m., united is at 14,000 feet and clear to descend to 5,000. at the same moment, twa flight 266, a super connie like the one that crashed over the grand canyon, is heading to la guardia airport. it's coming down through 8,000 feet. united is told to head to a specific navigational fix or intersection, where it's to enter a holding pattern and await further instructions, but there are problems. the plane has two navigational instruments used at the time to determine position. one of them isn't working.

and the plane is also traveling more than 500 miles per hour, a speed later determined to be excessive, and the dc-8 flies past its clearance. the united crew has lost its bearings. >> i would equate it to driving down a street. if you know where you are and you know the second left turn is the turn you need to make, that's great. but if you didn't see the first road to the left, you would drive beyond it because you didn't recognize the first cue. >> at 10:33 a.m., laguardia tower advises twa of traffic off to its right. no one realizes it, but the united dc-8 is heading straight for them. then, seven seconds later, as both planes approach 5,000, there's a brutal collision.

one of the dc-8's engines tears through the fuselage of the super connie. the twa plane breaks into pieces and goes down on the spot, crashing in staten island's miller airfield. but the united jet manages to stay aloft for 8 1/2 more miles until it's over park slope, brooklyn, where tom regan, then 20 years old, is standing on the street. >> i crossed the street at 7th avenue and sterling place, just stepping on the corner, when i heard a loud, loud whine. and when i turned around, the wing of the plane, united airlines, was catching into the roof of the building that i had just left. and there was a tremendous explosion. immediately i dropped to the ground. and then moments after that, there was a second explosion. bang!

just everything exploded. and now the whole place was on fire. i stayed on the ground for what i thought seemed to be a long time, but i believe it was only several seconds. and i jumped up and i ran and i never looked back. >> on the street in brooklyn, people are astounded to learn there's a single survivor. 11-year-old steven balce of illinois, who's thrown from the united plane into a snow bank. >> he had been given a christmas gift to fly alone from chicago to new york. and that's what happened. >> at the time, barbara lewnes is a recent nursing school graduate, working at methodist hospital, a few blocks from the crash site. she's assigned to care for steven overnight. he's badly burned. >> i couldn't tell if he was white or black. he was just charcoal. i think they said it was 85% of

his body. >> within hours, the boy's father arrives in new york and speaks to the press. >> how do you and your wife feel about your son being the sole survivor? >> we have great heartfelt sympathy for all of the people who were not as fortunate. >> the country rallies behind steven, but his injuries are too grave. >> if i had been in nursing longer, i would have known there was no chance, but that's why i think they put me there. >> steven, the sorry little 11-year-old boy, lone survivor of the plane crash in brooklyn, expired at 1:00 p.m., just a few minutes ago. the little boy closed his eyes and went to sleep. >> with a final death toll at 134, including 6 on the ground,

the 1960 crash over park slope replaces the grand canyon collision as the deadliest u.s. commercial aviation disaster to that point. to investigate the accident, the civil aeronautics board, the forerunner to the ntsb, uses flight data recorder, or black box technology, for the first time ever. the conclusion, united flight 826 proceeded beyond its clearance limit, or the place it was told to go into a holding pattern. its high rate of speed and the change of clearance or shortcut it was given by air traffic control are contributing factors. within three months, president kennedy establishes "project beacon." the task force is mandated to review the country's aviation facilities and put together a long-range plan for the future of air traffic in the u.s. but there are more midair problems on the horizon.

when we come back -- >> look at that! >> deadly accidents between large planes and small. >> all of a sudden, you know, we hear this big, this tremendous thud. i have asthma... ...one of many pieces in my life. so when my asthma symptoms kept coming back on my long-term control medicine. i talked to my doctor and found a missing piece in my asthma treatment with breo. once-daily breo prevents asthma symptoms. breo is for adults with asthma not well controlled on a long-term asthma control medicine, like an inhaled corticosteroid. breo won't replace a rescue inhaler for sudden breathing problems. breo opens up airways to help improve breathing for a full 24 hours. breo contains a type of medicine that increases the risk of death from asthma problems and may increase the risk of hospitalization in children and adolescents. breo is not for people whose asthma is well controlled on a long-term asthma control medicine, like an inhaled corticosteroid. once your asthma is well controlled, your doctor will decide if you can stop breo and prescribe a

different asthma control medicine, like an inled corticosteroid. do not take breo more than prescribed. see your doctor if your asthma does not improve or gets worse. ask your doctor if 24-hour breo could be a missing piece for you. see if you're eligible for 12 months free at mybreo.com. [we know a thing or two because we've seen a thing or two. ♪ we are farmers. bum-pa-dum, bum-bum-bum-bum ♪ looktry align probiotic.our digestive system? for a non-stop, sweet treat goodness, hold on to your tiara kind of day. live 24/7. with 24/7 digesve support. try align, t #1 ge recommended probiotic.

krous saying they hope to get a grip on the blaze. former noter dame running back was been declared brain dead. the gunman is at large. back to "why planes crash."

according to an mit study, technology has advanced to the point where we can expect only one midair collision every 100 million flight hours. the last time two commercial jets collided over the u.s. was the 1960 accident above new york city. since then, there have been three more midair collisions, all involving one large aircraft and one small. in 1967, mary's father is at the helm of a boeing 727 which collides with a twin cessna over north carolina, killing 82 people. >> two pilots show up and ring

the doorbell and inform my mother that my father's plane had crashed. and i told him that couldn't be true because he was the best pilot. >> the outgrowth of it was a very strong commitment by piedmont airlines to be involved into the traffic collision avoidance system. some years later, they were one of the first if not the first airline to fly with an active system on board. >> six years later, betty bare rot is aboard a charter jet when it collides with a dc-9 over france. everyone on betty's plane survives. >> my father was sitting in the aisle. i was on the right-hand side. i turned around. he is very british and stoic. i said, do you think we are going to make it? he said i rather doubt it and pointed to the wing.

somebody sent me this picture when we landed of the plane. as you can see, the tires are all blown out. this is the broken wing here you can see all this. and i was told that afterwards if we lost one more meter of our wing, it ends here, then we would have blown up as well. i keep this always in my room to remind me that if you survive this, you can survive anything. >> then there are two more midair collisions in the u.s. they force major change in the aviation industry. there are similarities. both occur in broad daylight on picture perfect days in southern california. the first on september 25, 1978 is caught on camera.

>> we heard a loud crash overhead and looked up to see part of a cessna airplane spinning to the ground. then suddenly, we heard a thunderous crash that sounded like a bomb hitting. >> no one knows it yet, but 17 seconds earlier, half a mile above them, the private plane has collided with a boeing 727. pacific southwest airlines, psa flight 182. >> come on, get in the car! come on, just take this! >> at the moment of impact, nbc channel 39 reporter john briton and his cameraman steven howell are covering a press conference just a few blocks away in the residential san diego neighborhood. >> john and i were on a standard news story. and i'm shooting shots of gas station pumps. >> i was standing about right here. steve, the cameraman, was right behind me, and county supervisor lucile moore was standing about right here.

and i was interviewing lucile standing here, and all of a sudden, you know, we hear this big -- >> something started falling out of the sky. people started just going, oh, my gosh, oh, my gosh. >> what is that? >> and i just clicked the camera on right away and just moved out to the left side, and i'm looking up, and something like a comet was coming down from the sky. >> the photographer for the county is standing over here on this side. so, when the collision happened, hans looks up this way and hans got off two shots of the psa-182 before it crashed. >> when i looked up, all i saw was the airliner with the engine on fire, and it was starting to bank to the right, and a big chunk of the leading edge of the wing was torn off. so, i knew that the plane, you know, had to crash. it couldn't possibly survive. and everything happened very fast.

i just got off one shot, sort of by instinct, and the second picture was almost the silhouette. >> cameraman steve howell and i rushed to the scene two blocks away. there were several homes involved in a raging fire. it was thick, black smoke shooting 300 to 400 feet into the air. >> it was just a wall of flames. i'm going, it must have been a gas main or something, you know. i mean, how could this be? >> this was the largest thing that had ever happened to me in my news career to that point, and i knew it was big, i knew it was bad, but we didn't know it was a plane crash. when we come back, how an assumption leads to tragedy. >> they're required to tell air traffic control that they no longer have the cessna in sight. that didn't happen. he said humira is for adults like me who have tried other medications but still experience the symptoms of moderate to severe crohn's disease. and that in clinical studies,

the majority of patients on humira saw significant symptom relief. and many achieved remission. humira can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers, including lyhoma, have happened; as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. before treatment, get tested for tb. tell your doctor if you've been to areas where certain fungal infections are common, and if you've had tb, hepatitis b, are prone to infections, or have flu-like symptoms or sores. don't start humira if you have an infection. ask your gastroenterologist about humira. with humira, remission is possible. text mom. i'll be right back. be good. boys have been really good today. send. let's get mark his own cell phone. nice. send. brad could use a new bike. send. [google:] message. you decide. they're your kids.

why are you guys texting grandma? it was him. it was him. keep your family connected. app-connect. on the newly redesigned passat. from volkswagen. because my teeth are yellow. these photos? why don't you use a whitening toothpaste? i'm afraid it's bad for my teeth. try crest 3d white. crest 3d white diamond strong toothpaste and rinse... ...gently whiten... ...and fortify weak spots. use together for 2 times stronger enamel. crest 3d white. then smash it into a tree.ch on a perfect car,

your insurance company raises your rates... maybe you should've done more research on them. for drivers with accident forgiveness, liberty mutual won't raise your rates due to your first accident. liberty mutual insurance. that's charmin ultra strong, remidude. cleans so well... ...it keeps your underwear cleaner. (secretly) so clean...you could wear them a second day. tell me i did not just hear that! (sheepishly) i said you could... not that you would! ...charmin ultra strong with its washcloth-like texture, helps clean better than the leading flat-textured bargain brand. it's 4 times stronger, and you can use up to 4 times less it cleans better. (to different boy) you should try it, "skidz." we all go. why not enjoy the go with charmin?

san diego, september 25th, 1978. an nbc news crew captures a small plane spiraling to the ground after it has collided half a mile up with a much larger 727. >> behind us we heard a tremendous explosion. we knew at that point it was a lot more than just a single plane. and of course, we found out later it was an airliner. >> both pilots in the cessna are killed along with all 135 aboard the jet and 7 people in the residential neighborhood below. police set up a makeshift morgue at a nearby high school, and immediately, the questions begin. who's at fault? what caused this tragic accident? how could it have been avoided? to understand what happened, it's critical to know what transpired between air traffic

control and the psa crew in the two minutes leading up to the collision. >> as the boeing 727 was approaching san diego, they were told about a small general aviation airplane. >> it's a cessna. do you see him? and the psa flight crew said, yes, we see them. at that point, the psa crew became responsible for maintaining separation. >> the crew initially saw the airplane, but then at some point lost sight of it. they talked about it amongst the three pilots that were in the airplane. yeah, do you know where that cessna 172 is? i think it passed off the right side. >> they're required to tell air traffic control that they no longer have the cessna in sight. that didn't happen. >> the cessna 172 actually deviated without clearance from its assigned heading. >> unfortunately, it was in a

position that was directly in front of but below the 727. the crew couldn't see just looking out the window where the airplane was because it was below their field of view. >> start to lift. >> the 172 struck the leading edge of the right wing about halfway across the span, and that is the famous picture. you see smoke and fire trailing from the right wing of the boeing 727. >> as a result, it pulled the nose further and further down and they couldn't stop it, and they lost control. they did not have control of the jet, and it tragically went into the ground. >> in its final report, the ntsb faults the psa crew for failing to maintain visual separation

from the cessna and for failing to inform the controller when they no longer had the other aircraft in sight. contributing to the accident, says the report, air traffic control procedures, authorizing controllers to use visual separation when radar was available. the report notes that flight crews exercise a lower degree of vigilance in areas where they receive radar assistance. and it says controllers seem to similarly relax vigilance. this controller may have believed that the flight crew had a better grasp on the situation than he did. >> it could be days before the cleanup is complete. and in the words of one policeman, it will be years before this neighborhood is ever the same. >> after the psa crash, the faa stepped up efforts to improve separation of aircraft around the nation's busiest airports and to modernize collision avoidance technology. but again, change simply doesn't happen fast enough.

eight years later, 1986, another sunny day over southern california, another jet, another small aircraft and another catastrophic midair collision. >> it was a sunday. it was in august. and my brother and i were playing on the driveway. my father was sitting on the lawn. and we were on our bikes. and i remember my brother just very casually said, look, there's a plane on fire, and it's coming down on our house. >> 6,500 feet above cerritos, california, a suburb east of los angeles, a privately owned piper archer has strayed into the path of aeromexico flight 498, a dc-9 with 64 people on board. at the time, corrine kingsbury

is 5 years old. >> my father came and swooped us and brought us in the garage. and our garage door was obviously open. and he said to us, "we're going to die." i remember it shook the ground and it just exploded. >> eight homes destroyed, five more severely damaged. 24 dead on the ground, and that number may go higher. >> i also remember seeing body parts and seats and people still in seats. it just smelled like death, like smoke and death. >> her house is spared, but many other homes in the neighborhood are not. when we come back, after the second midair collision in eight years, a public outcry for change, amid heartbreaking loss. >> i mean, who thinks your family is going to die in a plane crash. car accidents, not a plane crash.

♪ (music pl ♪ throughout) uh oh. what's up? ♪ ♪ ♪

does nobody use a turn signal anymore? ♪ looktry align probiotic.our digestive system? for a non-stop, sweet treat goodness, hold on to your tiara kind of day. live 24/7. with 24/7 digestive support. try align, the #1 ge recommended probiotic. so strap yourselves in for action flo! small business edition. oh, no! i'm up to my neck in operating costs! i'll save the day! for plumbers and bakers and scapers of lawn, she's got customized coverage you can count on. you chipped my birdbath! now you're gonna pay! not so fast! i cover more than just cars and trucks. ♪ action flo did somebody say "insurance"? children: flo! ♪ action flo cu can i get a smoothie, please? ooh! they got smoothies? for me.

good morning. the news from california keeps getting worse. officials are searching through the ruins of the crash, found 15 more people dead on the ground. >> labor day weekend, 1986. more than a mile above a suburb of los angeles, a piper crashes into a dc-9, a middle aged couple and their adult daughter, are killed. in the crash over san diego, eight years earlier, the larger plane, psa flight 182 loses sight of a much smaller cessna and slams into it from behind. over cerritos, the piper pilot doesn't realize he strayed into controlled air space surrounding

lax, los angeles international airport. >> when flying in uncontrolled air space, you don't necessarily have to talk to an air traffic controller, you don't necessarily have to have a transponder. but if you're going to operate anywhere in controlled air space, you have to have permission to operate in that air space. you can't just fly into it without permission. >> the dc-9 crew believed they were in protected air space, and they were. but unbeknownst to them, the piper strayed into their air space. >> the general aviation airplane struck the tail, taking off the vertical and horizontal stabilizers, literally the back of the airplane, it rendered it uncontrollable. the dc rolled and inverted, there's a famous picture of that plane as it is descending upside down before it crashes into a neighborhood. >> counting passengers and those on the ground, total number of people killed in the cerritos

crash stands at 85, that could go higher as the search for victims continues today, tuesday, september 2, 1986. >> in some ways, the midair collisions in cerritos and san diego are so similar, there's public outcry how little has been done in intervening years. >> after the first one, recommendations they made were never implemented. so now this is the second time this has happened. that's why we tried to make a difference, but it's hard to fight government othsys, you know. >> denise's family is particularly hard hit by the cerritos tragedy. her father-in-law, uncle, two nephews, and a family friend are on flight 498, returning from a fishing trip in mexico. her husband is supposed to be with them, but misses the trip to attend a funeral. when the plane crashes, part of the family is already waiting at the airport to pick them up.

instead, they head to the crash site. >> i mean, it was an inferno. we knew nobody was going to survive that. my husband may have had hope, are there any survivors, you know. but i knew immediately that this was not going to have a good ending. >> in the neighborhood struck by disaster, the search for the missing goes on. >> who thinks your family is going to die in a plane crash really, i mean, car accidents, not a plane crash. it's just like unheard of. how could that happen? and in our own neighborhood. that's what's really ironic, our own neighborhood. >> probable cause as stated in the final ntsb report, limitations of the air traffic control system to provide collision protection and the inadvertent and unauthorized entry of the private plane into los angeles terminal control area.

with the knowledge gained from each midair collision, change has been on the horizon for decades. but the aeromexico crash over cerritos brings it all home. by 1989, all aircraft operating up to 10,000 feet within 30 miles of terminal control areas must be equipped with transponders that convey altitude information. by 1993, all commercial carrier aircraft with ten seats or more operating within u.s. air space are equipped with traffic alert and collision avoidance systems. >> the culmination, beginning back with flight 22, going through the psa accident and finally through the cerritos accident were all building blocks to promote this technology which evolved into the modern system of tks which is a great predictive tool.

>> the faa had to take the bull by the horn if you will and do something to try to prevent these accidents from occurring. we increased or enhanced radar coverage. we enhanced air traffic control communication with flight crews. they changed the air space. they actually created a system of controlled air space, trying to avoid or at least mitigate the risk that you were going to have these transient pilots flying through high density areas in close proximity to major airports. >> all the lessons learned have made flying so safe and midair collisions so rare, according to an m.i.t. study, you'd have to fly continuously for 11,000 years in order to experience one. unfortunately many people had to lose their lives to arrive at what is surely the safest moment yet in aviation history.

a mysterious flaw brings down a boeing 737. >> all of a sudden i heard a big explosion. >> there's something going on that left no marks. no calling card. >> shortly after takeoff, a powerful explosion rips apart twa flight 800, igniting controversy about what really happened. >> if anybody thinks that this is involved in any coverup, they are wrong. >> conflicting commands put two jelt jets on a collision course.