Detroit's Fatal Fog: Unraveling The 1990 Wayne County Airport Runway Collision

The Overlooked Dangers of Taxiing: A Northwest Airlines Incident

On this blog, I often cover different phases of flight, mostly takeoff and landings, but I usually gloss over the phase that starts and ends every flight, the taxiing. But while this might be one of the less glamorous parts of each flight, it is actually where most of the nonfatal accidents happen even today. So failing to take it seriously would be a huge mistake with potentially serious consequences. This story takes us back to the 3rd of December 1990 at Detroit Wayne County Metropolitan Airport, Detroit in the US state of Michigan. Back then Detroit was a major hub for Northwest Airlines which used to be the sixth largest airline in the world before it merged with Delta back in 2010. For the 52-year-old captain at the center of this story, though, everything about this arrangement was actually brand new. He was employed by Northwest Airlines as a commander on the Macdonald Douglas DC9, but he had only worked for the company since October that same year after having returned from over 6 years of medical leave. He had originally started his flying career with Pacific Airlines back in 1966 and had then stayed with the company after it merged to form Huge Air West in 1968 and then again after Huge Air West was acquired by Republic Airlines in 1980. But in February of 1984, he had then been found medically unfit as a result of kidney stones, which forced him to take disability pay for a number of years whilst undergoing treatment. It then took over 6 and 1/2 years, as well as a personal bankruptcy before the FAA determined that he had overcome his condition and was finally fit to fly again. And meanwhile in 1986, while he was still away, his employer, Republic Airlines, had been acquired by Northwest Airlines, which is actually how Northwest got its Detroit hub in the first place. So when the captain came back, he found that he was now working for a completely different airline with different procedures and policies, something that would have been a quite disorienting experience for him. He had also spent so much time away from flying that his type rating had lapsed and that meant that he had to repeat the DC9 initial training course as well as 23 hours of initial operating experience before he was allowed back as an unsupervised pilot in command again. Fortunately, he was very dedicated to his craft and was therefore able to pass his check ride with flying collars on the 30th of November 1990, just 3 days before today's story. Now, overall, the captain had an impressive 23,000 flying hours, including over 4,000 on the DC9. But due to the reasons that I just explained, most of those hours were not very recent.

Captain's Background, Pre-Flight Routine, and First Officer's Persona

Anyway, on the morning of the 3rd of December, he woke up, skipped breakfast, and then went straight to the airport, where he tracked down Northwest Airlines chief pilot to pay him a courtesy visit. He then also took some extra time to review the paperwork for flight 1482 over to Pittsburgh, Pennsylvania, which was going to be his first unsupervised flight since his return back to the line. This all meant that he didn't have time to eat lunch and he therefore reported to the gate without having eaten anything since late in the previous evening. Now, the final report on this accident doesn't indicate that the captain's fitness was affected in any way by this lack of food, but modern research has suggested that being hungry can indeed have detrimental effects on pilot performance. So, that's something that's worth keeping in mind here. Anyway, at the gate, the captain then met with the first officer for this flight, who, as it turns out, was quite a character. He was 43 years old and had recently retired from the US Air Force with the rank of major after a 20-year long career flying the B-52 Strata Fortress and the T38 Talon trainer. After that, he had been hired by Northwest Airlines back in May of 1990 and had so far accumulated a total of 4,685 total hours, of which only 185 were on the DC9. Because he had been working for Northwest for less than a year, he was also still on his probationary period. So, his performance would therefore be evaluated by every captain that he flew with, meaning that he was probably quite keen to impress here.

Unusual Crew Pairing and the Authority Gradient Challenge

Now together, these two pilots actually made up a quite unusual pairing. For example, even though Detroit was a hub for Northwest Airlines, neither of them had much recent experience there. And the first officer also had a lot of command experience from the military. Actually, more recent command experience than the captain did, coupled with a quite assertive personality. Now, for those of you who have been following this blog for a while, you might be thinking, "Great, here's a first officer who will therefore demonstrate good resource management, CRM, by speaking up if he would notice that the captain would make a mistake or something." But it turns out that things weren't quite that simple. To understand why, we need to think of a crew composition in terms of the authority gradient, which is basically the difference between the perceived authority of the captain and the first officer. If the authority gradient is too steep, well, then the first officer might just do whatever the captain says, which leads to poor crew resource management since the first officer often have valuable opinions that then won't be taken into account. But at the same time, if the authority gradient is too flat, then it can be unclear who is actually in command, which comes with its own set of problems like indecisiveness, for example. But if the first officer is very assertive and the captain is passive, well, then the authority gradient could actually reverse and that could cause some real problems as well. If the captain is making the decisions based on what the first officer says or thinks without taking his own thoughts into account, well then that's likely even worse than the other way around. These kind of issues are addressed in basic CRM training which all airline pilots receive today. But back in 1990, Northwest Airlines didn't have a CRM program yet. In fact, despite being involved in early CRM research, they were one of the last major US airlines to develop such a program.

Pre-Flight Preparations Amidst Worsening Weather

Anyway, after entering the aircraft together, the captain and first officer completed a pre-flight preparation and looked through the technical log, which showed that there were no significance issues with the aircraft. But the weather outside was now shaping up to become the major problem instead. Since the previous day, snowfall had given way to rain, accompanied by a dense fog that now completely blanketed the airport and was actually getting worse by every passing minute. By 12:50 local time, the National Weather Service observations for Detroit airport indicated 3/4 of a mile visibility with overcast at 200 ft., fog, and wind from 1 to 0° at 11 knots. This was pretty poor, but still good enough to allow for takeoff and landings, as long as it didn't get any worse. On board flight 1482, things were moving along smoothly. And the two pilots finished preparing the aircraft for flight around 40 minutes before their scheduled departure time. This meant that they could just sit back, relax, and continue just chatting about various topics while they waited for their passengers to finish boarding.

Miscommunication on Airport Familiarity and Lack of Taxi Briefing

During that chat, the captain asked the first officer whether he was experienced with operations at Detroit airport, to which the first officer replied that he was indeed. But what the first officer actually meant by that was that he was familiar with the radio and push back procedures, not the actual airport layout. The captain, however, assumed that if the first officer was familiar with the airport, well, then he should know the airport layout pretty well, which kind of makes sense if you think about it. It's very likely that this confidence in the first officer's knowledge lulled the captain into a false sense of security and that he therefore maybe thought that he didn't need to study the taxi charge quite as closely. Now, I have to stop here and say that even when the visibility is good, it is super important to conduct a thorough taxi briefing to make sure that both pilots know and understand the route that they will need to follow. But that unfortunately didn't happen here.

The First Officer's Fabricated Military Stories

At time 1335, the cockpit voice recording began, at which time the crew were discussing various procedures and policies that had changed during the years that the captain had been away. The pilots also decided to ask the ground crew to check the tail for ice, which then led them to discuss the dangers of eyes on tail in general. And as they were doing that, the first officer commented, "See, that's something that I miss. I've always flown with an ejection seat. used it twice. The captain asked whether it was scary when he punched out, to which the first offer replied, "I got shut down over Southeast Asia, and I didn't have time to get scared." He then went into a lengthy and animated description of the other time he had to eject, which was when he suffered an engine fire takeoff in the T38 trainer. And during this time, the captain basically just nodded along and periodically said things like, "Wow, and is that right?”. The problem though was that none of what the first officer was saying was actually true. According to his military records, he had never been involved in any previous accidents or incidents during either combat or peace time, and he definitely had never used an ejection seat. The captain then asked him how long he had been in the military, to which the first officer explained that he had been in the service for 20 years and that he had retired as lieutenant colonel. But that wasn't true either. He had actually retired as a major which is one rank below lieutenant colonel. So the first officer was clearly engaged in a pattern of was at best embellishment and at worst serial lying here. And you have to wonder for what purpose? Well, it is possible that he might wanted to make a favorable impression on the captain who knew was going to review his performance. But it goes without saying that lying about one's experience and status, especially military rank, is a pretty unprofessional conduct. It can also be detrimental to the crew resource management in this case because the first officer's bragging and self-embellishment likely initiated a slightly inverted authority gradient here. Remember, the captain was about to do his first flight after a long time away, and he likely now felt that he was going to operate together with a real ace, a strong leadership figure that could definitely be relied on. And that's worth to keep in mind.

Pushback, Taxi Instructions, and Detroit Airport Layout in 1990

Anyway, by time 1332, all 40 passengers had finally boarded the DC9. So, along with the four crew members, there were 44 souls on board. When the pilots decided that it was finally time to start pushing back from the gate, the west sector ground controller then cleared them for push back. And the pilot soon started up the two engines and completed the aftercare checklist. And as they were moving back from the terminal, the first officer gazed out through the dense fog and said, "Look at the viss out there now." But the captain didn't respond to that. After the crew reported ready, the ground controller then told them to turn right out of the parking and then taxi to runway 03 center, exiting the parking apron at the taxiway Oscar 6. So where is that exactly then? Well, before we get any further, we need to take a look at the layout of the taxiways and runways in the vicinity of the Northern Terminal Complex where flight 1482 had now been parked. Back in 1990, the layout of Detroit airport was considerably different than it is today. And actually, back then, what's now known as the Northern Terminal Complex was the only terminal complex because the southern one hadn't been built yet. Furthermore, Detroit airport today has six runways, but back then there were only four of them. Three of these ran from the southwest to northeast and were known as 03 left, 03 center, and 03 right or to one right center and left from the other direction. The fourth runway was 0927 which cut straight across the middle of the airport intersecting all three of the other runways. Because of this layout, it wasn't possible to use any of those runways at the same time as 0927, which was very inefficient. So this middle runway was inactive most of the time. Now the terminal complex was located between runway 03 left and 03 center and to the north of runway 0927. The area bounded by these three runways and the terminal building mainly contained a large apron with numerous gates and around the edge of this apron was a taxi route known as the inner taxiway. Inner meaning it was closer to the terminals. Various short connectors then span the gap between the inner taxiway and the parallel outer taxiway. All of which were known by their call sign Oscar and a number indicating their position. Some of these Oscar taxiways including Oscar 6 and Oscar 4 also connected the outer taxiway to the surrounding runways. So basically you have three concentric layers here. the runways on the outside, the outer taxiway within them, and then finally the inner taxiway closest to the terminal. And then you have the Oscar taxiways radiating outwards across these layers, creating a web like network.

Navigating Detroit Airport: Taxiway Instructions and Visual Aids

So with that in mind, let's consider the taxi instructions given to flight 1482, which were to taxi to runway 3 center and exit apron at Oscar 6. To do this, the flight would have to follow the inner taxiway until the turn off to Oscar 6, then follow Oscar 6 across the outer taxiway and across runway 0927. The continuation of Oscar 6 on the south side of the runway 0927 was then called taxiway Foxtrot, which eventually intersected with taxiway X-ray. That taxiway in turn ran parallel to the left side of runway 03 center from its threshold and up until across runway 0927 until it then intersected with the outer taxiway at Oscar 4 as you can see on this map. So after following Foxtrot the flight would have to turn right onto X-ray follow it up to the threshold of runway 03 center and then finally turn left and enter the runway. Now, that's probably way too much to keep in your head at one time, which is why I've drawn it out on this neat map in front of you. And by the way, that's exactly what we pilot should also do when we get a clearance like this. Even in good visibility, taxiing on a complex airport like Detroit forces us to rely very heavily on signets, markings, and our taxi charge. And that obviously becomes even more important if the visibility is poor. Now, the taxiway signs are mounted on the grass islands between the paved areas in order to mark the taxiways or runways ahead of them, much like street signs do. And sometimes these signs are also equipped with arrows on them to clarify which taxiway they're referring to. Taxiway markings, on the other hand, is something different, and those are normally painted directly onto the pavement. Each taxiway has a center line marking to help pilots follow the taxi way without getting too close to the edges. And at the intersections, the center line markings then split and arc outward towards the intersecting taxiway to help pilots turn at the correct location. And the idea is to try to straddle the center line with the main gears. So you're not going to follow it with your nose gear. You're just going to make sure that your main gears are on the equal sides of it. Then where taxiways intersect with runways, hold lines are painted perpendicular to the taxiway to indicate to the aircraft that's coming that they must stop and receive clearance to cross the runway before they can proceed. Today, we also have more advanced systems involving different colored lights, which I will talk a little bit more about later, but for now, what I've described so far is basically what was available to the pilots of like 1482 back in 1990.

Lost in Fog: The Initial Wrong Turn

So in this case, what the pilots should have done was to find the center line of the inner taxiway, follow it around the edge of the apron until reaching the Oscar 6 intersection, then follow the center line of Oscar 6 across the outer taxiway and up to the hold line for runway 0927 where they should then have stopped and verified that they had permission to cross. Simple, right? Well, no. It turns out that the center line markings on the Indian taxiway near the Oscar 6 intersection were so faded that it was quite hard to follow them even in perfect weather and let alone in the kind of fog that these pilots were now maneuvering in. So the complications here started quite early. After completing the before taxi checklist, the captain told the first officer to watch and make sure that I go the right way. He then tried to taxi to the inner taxiway, but the center line was so faded that none of the pilots could actually see it. So, navigating using landmarks instead, the first officer told the captain to um just kind of stay on the ramp here. The captain asked until the yellow line, I guess, presumably meaning the yellow center line of the inner taxiway. And he then commented that the fog was really bad. to which the first officer agreed and commented that the visibility looked like it was actually approaching nil. But neither pilots saw this as something that should stop them from continuing their taxi. As they slowly started moving along the apron, the crew then switched over the frequency to the east ground controller who responded by asking them where they were. The first officer reported that they were passing the fire station to which the controller replied with an instruction to taxi via the inner taxiway to Oscar 6 then Foxtrot and report making the right turn onto X-ray. The first officer read that back correctly then glanced over at his map and noted that Oscar 6 crosses runway 0927. At that point, they finally reached the Oscar 6 intersection without ever having actually assumed the center line of the inner taxiway. If they had, they would have clearly seen the center line of Oscar 6 arcing away to their right. But they were now too far to the left to notice it. Instead, what they saw was a different center line arcing off the inner taxiway through the left edge of Oscar 6 and onto the outer taxiway. On top of that, the sign marking Oscar 6 was located in the grass island between the inner and outer taxiways, and it was unclear whether it was pointing southeast down Oscar 6 or east down the outer taxiway. Now, an arrow would have easily rectified this confusion, but unfortunately, there wasn't any. As a result of this, the first officer believed that they should now follow the center line to the left to join Oscar 6 when actually this would take them onto the outer taxiway instead. He said to the captain, "Uh, guess we turn left here." To which the captain asked, "Left or right?" And the first officer then assured him that the left turn would take them to Oscar 6 near as he could tell which he then added to by saying, "Man, I can't see out here." Now, using the tiller, the captain maneuvered the DC9 onto the scent line of what he thought was Oscar 6, but was actually the outer taxiway. While making this turn, he asked the first officer to repeat the runway they were heading for and commented that we got to be below minimums. The first officer assured him that if the visibility was below minimums, the controller would tell them, right? Well, we will get to that.

The Control Tower's Limited Tools and Initial Confusion

Now, taxing slowly down the outer taxi way, the captain called for the before takeoff checklist to be completed, which the pilots then did for the following 20 seconds. So far, nobody had realized that flight 1482 had made a wrong turn. But that was about to change. And to understand what happened next, we need to also take a look inside of the control tower. At the Detroit Tower that day, there were several controllers at work. But the ones that we need to look at are the tower controller, the east ground controller, and the tower supervisor. The tower controller was responsible for all movements on or near the actual runways. He was only 25 years old, but already had 2 years of civilian air traffic control experience and 5 years of military ATC experience, which isn't a lot overall, but quite impressive for that age. The east ground controller similarly had six years of ATC experience already at age 26, but he had only been working at Detroit since July of that same year. And lastly, the 35-year-old tower supervisor had by far the most experience at Detroit with eight total years of experience, including over five at the airport. Her job was to ensure that the other controllers carried out their duties correctly and smoothly. But she was not necessarily required to provide active direct monitoring of her subordinates’ frequencies as they were dealing with the traffic. In fact, she was not closely following the activities at this point at all. She was handling some paperwork instead. But the investigators later wrote that she should have been looking closer since the visibility by that point was the worst it had ever been during her career. This was especially significant because the Detroit control tower didn't have any kind of technology such as airport surface detection equipment, ground radar that would help them determine the locations of taxiing aircraft. So they were relying completely on accurate pilot reports.

Ground Controller's Misinterpretations and the Pilots' Growing Disorientation

But so far at this point, things were actually running smoothly. That was until time 1339 when the east ground controller asked flight 1482 for their position. The first officer replied by saying that they were on Oscar 6 approaching the parallel runway, but the ground controller wasn't sure what he meant. So he asked for clarification and the first officer then answered that he was headed eastbound on Oscar 6. Now that just wasn't possible since Oscar 6 runs northwest to southwest, meaning that you can't be taxiing eastbound on it. And the ground controller probably should have noticed this, but he didn't. So he just told flight 1482 to report crossing runway 0927. But now the first officer did realize that something was off. So he said to the captain, "Okay, I think we might have missed Oscar 6. See a sign here says that uh the arrows to Oscars five. I think we're on Foxtrot now." But that statement made absolutely no sense. They were in fact next to Oscar 5, but Oscar 5 connected the inner taxiway to the outer taxiway. It didn't intersect with Foxtrot. Not to mention that Foxtrot was on the other side of runway 0927, which they hadn't even crossed yet.

The Perils of Being Lost on the Airport Surface

Either pilot could have determined here that they weren't on Foxtrot by just checking their airport taxi map, but none of them did. And here I want to point out something that might not be very obvious. Once you're already lost, orienting yourself on an airport can be extremely difficult. This is why we always train our pilots to just stop and hold position and then request a follow me car if they ever find themselves in a situation like that, especially without ground radar. But the first officer most likely didn't want to admit that he was lost. After all, the captain had kind of delegated the navigation to him, and he knew that the captain was going to submit an evaluation later, so he would have likely felt pressure to get things back on track before the captain realized that he didn't know what he was doing. Now, the captain should have recognized that the first officer wasn't sure of where they were, but he had by this point conceded so much authority to the first officer that he just didn't. So after telling the controller that they were on Foxtrot, the first officer just told the captain to keep going straight, which he also did, but at a very low speed due to the extremely bad visibility. Meanwhile, the ground controller realized that flight 1482 must be on the outer taxiway. So he asked the crew to confirm that, which the first officer then did, despite moments earlier saying that they were on Foxtrot.

Missed Opportunities for Air Traffic Control Intervention

And here the ground controller had several options for how to proceed. For example, recognizing that flight 1482 was having difficulty navigating, he could have started issuing progressive taxi instructions, meaning instructions that are issued one step at a time as opposed to describing the entire route all at once. This can be very helpful in navigation if it's really tricky out there due to bad visibility, but that mostly is done when you have access to ground radar, which the controller didn't have. Without that, he would need to know for sure where the aircraft was in order to do it, and that was a bit tricky in this situation. Alternatively, he could have only cleared them as far as to the next intersection where the crew could have then stopped and made sure that they were fully aware of where they were and where they needed to go after that. He would have also been within his rights to ask the tower controller to hold takeoffs until they were certain of where the DC9 was. But remember, the ground controller had no idea that this was a very rare NWA crew who didn't know the layout of their airline's biggest hub. So he probably didn't think it was necessary to babysit the crew too much.

The Confusing Oscar 4 Intersection and Further Disorientation

This meant that instead of doing any of those things, he just gave them a new instruction to continue to Oscar 4 and then to turn right onto X-ray. Again, that sounds simple, but again, the answer is that it wasn't. You see, the next intersection was a six-way junction between Oscar 4, the outer taxiway, taxiway X-ray, and taxiway Victor. This intersection had actually been flagged to the airport authorities as an area with a high risk of inadvertent entry into an active runway because the problem was that there was so many options for where to turn and three of them led directly onto the runways. Taxiway X-ray immediately crossed over runway 0927. Taxiway Victor immediately crossed runway three center 21 center. And the outer segment of Oscar 4 led directly into the middle of the intersection between the two runways. And that fact was not clearly marked anywhere. While traveling eastbound on the outer taxiway, X-ray would have been the first exit to the right. But by the time the aircraft was actually in a position to turn onto X-ray, the sign marking the location of X-ray would no longer be visible. So at that point, both X-ray and the outer segment of Oscar 4 would appear to be signed identically because each of them just had an adjacent sign indicating that they led to runway 0927. And that even though Oscar 4 also led to runway 3 center, which again was not indicated anywhere. On top of all of this, the ground controller's instructions to taxi to Oscar 4 and then turn right onto X-ray implied that one would turn onto X-ray after reaching Oscar 4. But in reality, an aircraft turning from the outer taxiway onto X-ray would actually never reach the center line of Oscar 4 at all. This intersection was so confusing that when the NTSB later taxied an airplane onto Oscar 4 in broad daylight and with good visibility, the investigators still couldn't agree on which taxiway was which.

Confirmation Bias and Entry onto the Active Runway

Now, the pilots of flight 1482 were approaching the same intersection in almost nil visibility. So, you can probably imagine where this is going. As they were nearing the junction, the captain spotted a sign pointing to runway 0927. While the first officer glanced behind him and noticed the sign pointing to X-ray, the captain seemed confused and asked, "So, what does he want us to do here?" To which the first officer replied that they were supposed to make a right turn and report crossing runway 0927. The first officer then pointed out Oscar 4 and what he thought was X-ray, although by this point there were no visible signs pointing to X-ray at all. The captain taxied the aircraft up to the Oscar 4 center line, by which point X-ray had already passed behind them, and the only remaining right turn was the continuation of Oscar 4 onto the intersection of both the two runways. The captain now asked if they should go that way, and the first officer replied that they should. So, the captain just executed a right turn onto Oscar 4. About 20 seconds later, the first officer felt a sudden pin prick of doubt and he started to say, "Well, wait a minute. Oh this is uh" But before he could question himself any further, he assertively and incorrectly proclaimed that they now must be on X-ray. A classic case of confirmation bias. The captain though still had some doubts, so he started urging the first officer to call air traffic control. But before he could finish, the first officer declared that they were approaching runway 0927 on a heading of 160 degrees and that they were clear to cross it. Now, they were indeed taxiing on heading 160. And it so happens that heading 160 was the heading they would expect to see when crossing runway 0927 on Oscar 6. But the problem was that they weren't on Oscar 6. They were supposed to be on X-ray, which had a heading of about 200° instead. But again, neither pilot checked the map, which would have revealed this mistake. So, the first officer just told the captain that they were cleared to cross, and flight 1482 began to slowly creep out into the foggy runway. But the problem was that this wasn't just runway 0927. It was also the active runway 3 center. And the pilots had no idea that another aircraft was at this very moment lining up for takeoff.

Northwest Airlines Flight 299: A Collision Course

That aircraft was Northwest Airlines flight 299, a three engine Bing 727 bound for Memphis, Tennessee with 146 passengers and eight crew members on board. The captain of that flight was 42 years old with 10,400 flying hours. And the first officer was 37 years old with 5,400 hours. The flight crew also included a 31-year-old flight engineer, officially referred to as a second officer, who had 3,300 flying hours in total. And flight 299 had originally pushed back from the gate at 13:31, an hour and 21 minutes behind its regular schedule. After push back, the ground controller had instructed them to taxi to runway 3 center for takeoff via the inner taxiway, Oscar 6, Foxtrot, and X-ray, exactly like flight 1482. And in fact, as they entered Oscar 6, the crew of flight 299 had caught sight of flight 1482 disappearing into the fog down the outer taxiway, although they didn't think anything about it at the time. While taxiing, the pilots then listened to the automated terminal information service broadcast 80s, in order to get the latest weather observations. When they started taxiing, the 80s was reporting 3/4 of a mile visibility. But as they got closer to the runway, the visibility had deteriorated significantly. So the captain told the first officer to check the 80s again and compare it to their company minimums for takeoff. A new 80s had just been released and was now reporting one quarter of a mile visibility, which happened to be exactly the minimum visibility required for them to be allowed to take off. Shortly after having received that, plat 299 had crossed runway 0927 and begun taxing along Foxtrot where the pilots started up the number three engine. After turning right onto X-ray, they had then been handed over to the tower controller to await their takeoff clearance. And at that time, they just barely managed to see the runway 3 center run up pad from about 1/3 of a mile away. The visibility was now getting rapidly worse. After stopping at the hold short line for runway 03 center, flight 299 then reported ready for departure and the tower controller quickly cleared them for takeoff.

Detroit Collision: Visibility, Checklists, and Pilot Decisions

The captain taxied the aircraft into position but then stopped to finish up the last items of the before takeoff checklist, double-checking the anti-skid, boost pumps, transponder, and a couple of other items. And this took a few seconds extra. Just after finishing the checklist at time 1344 and 59 seconds, the first officer commented, "Boy, this is dog now." Referring to the fog outside, and the captain agreed, but he started advancing the trust levers for takeoff anyway. The first officer then added, "Definitely not a quarter of a mile, but h at least they're calling it." Acknowledging that to his untrained eye, it was apparent that the visibility was now less than one quarter of a mile, which would indicate that it was also below Northwest Airlines takeoff minimum. But still, the pilots concluded that they were okay to depart as long as a traffic control was reporting a visibility equal to or greater than the minimum one, even if that reported visibility appeared to be wrong. Later, the captain testified that he believed that it was safe to take off despite the bad visibility because he was able to see enough runway center line markings to keep the nose straight during the takeoff. And to be honest, I think that probably 99% of pilots out there would have done the same thing. But if the reported visibility had been lower, then they would have definitely not taken off.

Inaccurate Visibility Assessments and Faulty Airport Infrastructure

So why was it reported higher than it apparently was then? Well, controllers at the Detroit Tower had been taught to assess the visibility by referring to a chart of airport landmarks located at certain known distances from the tower, with the visibility in a given direction being equal to the distance of the furthest visible landmark. In this case, the judgment of one quarter of a mile was made by the tower controller and the supervisor, but neither of them actually referred to that short, nor did they have that chart memorized. In fact, later the east ground controller said that he agreed that the visibility was one quarter of a mile, but he also stated that he couldn't see the aircraft at the end of the Alpha, Bravo, and Charlie concourses, which was less than one quarter of a mile away from the tower. At the same time, an off duty controller who was preparing to come on duty around 13:30 decided to take a visibility measurement using the chart, and she concluded that the actual visibility was only 1/8 of a mile. When she then went to the tower controller and asked him if he wanted to change the reported visibility to 1/8 of a mile, the tower controller declined to do so. Now, if anyone had told Northwest Airlines flight 299 that the visibility was now 1/8 of a mile, the flight would have not taken off. and the sequence of events would have stopped here, but it didn't.

Missing Clues: The Illusion of a Closed Runway

Anyway, as all of this was taking place, the captain of the DC9 had started to taxi the aircraft out onto the intersection of runway 0927 and 0321 center at the first officer's urging. Now, there should have been plenty of clues that this was an active runway, not the closed runway 0927, but as it turns out, most of those clues were unfortunately absent. When a runway is not in use, the runway edge and center line lighting is normally turned off. So, if that lightning is turned on, then that's a very obvious indicator that the runway is in fact being used. But the spacing of the edge lighting on runway 0321 center in the area of Oscar 4 was wider than permitted and in the current visibility that meant that it was only possible to see one light at a time. Now the runway center line lights were spaced 50 ft. apart and would have been clearly visible if they were turned on, but they weren't. Now, the tower controller believed that the center line lights on Roma 03 center were set to the maximum brightness, but in fact, they were off due to a poorly designed switch in the control tower. And since the airport charge at the time didn't include that this runway should have any center line lights at all, none of the pilots who were departing questioned this, and the controller couldn't see the runway themselves because of the fog. Lastly, there were a pair of flashing orange taxi hold position lights, wigwags, designed to indicate that there was an active runway ahead, but these weren't required by the FAA at the time, and the ones at Oscar 4 had therefore been left inoperative for months. As a result of all of this, there was very little indication to the crew of the DC9 that they were now entering an active runway.

Confusion, Doubt, and the First Officer's Assertions

Nevertheless, after entering, the captain caught sight of a single edge light through the fog. So he asked the first officer, "Um, this is the active runway here, isn't it?" But the first officer confidently reassured him that no, this was runway 0927. So the captain kept taxiing forward, but continued to express doubt as he asked the first officer whether he was sure that they were clear to cross. And the first officer again just assured him that yeah, they were. But as the other side of the runway came into view, they only saw grass where they expected to find taxiway X-ray, prompting the first officer to ask, "Is there a taxi way over there?" The captain said, "Nah, I don't see one." And then he stopped the aircraft and set the parking brake in the middle of the active runway 03 center. He now instructed the first officer to call air traffic control and tell him that we can't see nothing out here. But at that moment, the ground controller asked for their position and the first officer replied that they were at the intersection of X-ray and runway 0927 holding short of the runway, which was not at all true. Hearing this, the controller just cleared them to cross runway 0927 again. So, the captain released the parking brake and started creeping forward once more.

Growing Realization and Communication Breakdown

But now he suddenly realized that there were two runways ahead of him and he exclaimed, "Now what runway is this? Is it a runway?" The first officer told him to turn left over here, pointing down runway 0927. But the captain just replied that there was a runway to there. Realizing that there was no taxi way ahead of them, only two intersecting runways, the captain again instructed the first officer to tell air traffic control about their situation. But again, the first officer did not comply. Unsure where to go, but worried about being on an active runway, the captain taxied as far forward towards the opposite edge of the runway as he could without running into the grass, coming to a stop with his nose pointed towards the threshold of runway 03 center and the right wing protruding out towards the center line. At this point, the captain finally decided to exercise his command authority and called air traffic control himself. But his first two attempts were on the wrong frequency and there was therefore no response. He might have just had his audio control panel set up wrong. We don't really know.

ATC's Delayed Response and the Looming Disaster

Meanwhile, the ground controller was now starting to get suspicious. So he called and asked flight 1482 to verify that they were proceeding southbound on X-ray and that they were clear of runway 0927. At this point, the captain had finally managed to select the correct frequency and replied, "Uh, we're not sure. It's so foggy here, and we're completely stuck." The controller then asked with increasing urgency whether they were on a runway or a taxiway, and the captain said that they were on a runway by Oscar 4. The controller then continued asking them to confirm that they were clear of runway 03 center. At which point the first officer finally realized their predicament and exclaimed that they must in fact be on runway 0321 center. This caused the captain to call out that they were in fact on runway 21 center which the controller asked him to please verify and he then replied, "I believe we are. We're not sure." In hindsight, the ground controller should have raised the alarm as soon as flight 1482 admitted that they were unsure of their position given their likely proximity to the active runway. But instead, he spent 27 seconds trying to get the crew to verify whether the flight was in fact on the active runway. Only after receiving the verification did he announce to the entire tower cab that there was a lost aircraft out there that might be on the runway. And because the supervisor had not been monitoring the situation directly, she had been unaware until that point that flight 1482 was in any difficulty.

The Tragic Collision on Runway 03 Center

But as soon as she heard the ground controller's call, she immediately shouted, "Stop all traffic." At that very moment, Northwest Flight 299 had already been cleared for takeoff and was now accelerating down runway 03 center, hurtling through the impenetrable fog faster and faster. The first officer called out 80 knots, which the captain acknowledged, and the aircraft then just kept accelerating. Meanwhile, the tower controller heard the command to stop all traffic, but he made a split-second decision not to warn flight 299 because he believed that they were already airborne. The 727 hadn't appeared on his radar display yet, but it had been over a minute since he had issued the takeoff clearance, so he was sure that the flight had already departed. He had had no idea that the crew of flight 299 had actually waited 48 seconds after receiving the takeoff clearance to finish the last checklist items before they commenced their takeoff rule. Now, we don't know for sure whether the tower controller could have warned the 727 in time even if he tried because the exact timing of the supervisor's call to stop all traffic is not known exactly. But it is possible that this unfortunate judgment call eliminated the last opportunity to avert a now inevitable disaster. On board the 727, the pilots had obviously no idea that the tower supervisor had just ordered all aircraft to stop. Accelerating through 100 knots amid the extremely dense fog. They also had no chance of seeing the DC9 until the very last second. At time 1345 and 39 seconds, the pilots of the 727 suddenly saw the lost airplane emerge like a ghost from the fog directly in their path. The captain let out an exclamation of surprise and then jerk the joke hard to the left in a last ditch attempt to avoid the DC9, but it was too late.

Impact and Immediate Aftermath for Flight 1482 and 299

On board the DC9, the pilots had heard a ground controller transmit northwest 1482. If you're on 21 center, exit that runway immediately, sir. But before they could reply, the 727 suddenly appeared out of nowhere, barreling down the runway directly towards them. The first officer threw himself down and to the left as the 727's wing tip impacted the windscreen and instrument panel directly in front of him, showering both pilots in broken glass and bits of flying metal. The wing tip then tore all the way down the side of the DC9 passenger cabin like a giant horrific knife, cleaving open the fuselage just below the window line. Three passengers in the right side window seats were instantly killed as the wing ripped down the entire length of the cabin before it finally impacted the DC9's rear-mounted right engine, which was ripped straight off the plane along with the outboard 4 m of the boy 727's right wing. And after that, the 727 then disappeared back into the fog as quickly as it had come. But this story was obviously far from over. On board the 727, the pilots had felt a tremendous impact. But the captain was still able to keep the plane straight and he immediately called out, "Abort." He then slammed on the brakes and quickly managed to bring damaged plane to a stop about 640 m beyond the sight of the collision. Now, the damage to his aircraft was extensive with the outboard portion of the right wing missing and the rest of the wing also being heavily damaged, and the outboard 1 meter of the DC9's right wing tip was later also found embedded in the 727's right main landing gear door. As the plane came to a halt, the first officer reported to the tower that they were aborting. And the controller asked him for the nature of the problem, to which the first officer replied that there was an aircraft on the runway and they had collided with its wing. Fortunately, though none of the 154 people on flight 299 had been hurt in the collision. A little bit of fuel was leaking from the wing, but it was now raining outside and the fuel was flowing away from the aircraft. So the captain decided not to immediately evacuate. A few minutes later, the first fire trucks arrived and started spraying foam on the damaged right wing. And a little while later than that, the passengers deplaned with their baggage through the 727's ventral air stairs and were later brought by buses to the terminal. But meanwhile, the fire crews soon realized that they hadn't received any distress call from the DC9. So with a sinking feeling in their stomachs, they started making their way back up the runway to look for it. And when they arrived, they discovered to their horror that the entire airplane was now already fully engulfed in flames.

Fatal Flaws: Evacuation Challenges and Maintenance Errors

Immediately after the collision, the DC9's captain had pulled the fuel cutoff switches to shut down the engines and had then shouted for the passengers to evacuate. The forward flight attendant had been standing in the cockpit door during the crash and had been thrown violently to the ground and as a result of that several surviving passengers reached the L1 exit door before she did and tried to push it open. But these untrained passengers failed to open the door all the way. So the evacuation slide didn't deploy or inflate, forcing them to jump unaided down to the ground. At the back of the plane burst fuel lines from the DC9's right engine and the 727's wing had sprayed fuel all over the tail, which ignited, sending black smoke and fire pouring through the gaping hole in the side of the fuselage. All the exits on the right side were either destroyed in the collision or blocked by the fire, so they couldn't be used. But one passenger managed to open the left over wing exit through, which a lot of the passengers could escape. Now, the DC9 also has a unique tail cone exit, which can be opened by pulling a handle that jettison the entire tail cone to create an escape route. The rear flight attendant and a male passenger immediately went for that tail exit, but when they pulled the handle, the exit didn't open. It was later discovered that serious organizational and training problems existed at Northwest Airlines maintenance facility in Atlanta, where the tail cone exit on this DC9 had previously been serviced. After a regular inspection, the cables connecting the tail cone exit handle to the latches had been miss rigged by a poorly trained mechanic, and as a result, too much slack was left in the cables, making the exit impossible to open from the inside. Evidence later indicated that in their desperation to escape, the flight attendant or the passenger pulled so hard on the useless exit handle that the shaft actually snapped in two and in the end they were cut off from the cabin by the dense smoke and fire and both perished inside of the tail cone due to smoke inhalation.

Casualties and Long-Term Safety Improvements from the Accident

Meanwhile, an off duty flight attendant helped some injured passengers away from the plane while the captain left the plane via his side window. The first officer had miraculously survived the initial collision and was now able to extract his injured leg from the twisted remains of the instrument panel in time to escape the aircraft before it was completely consumed by fire. Unfortunately though, three more passengers never managed to reach any of the exits and they succumbed to the smoke and fire while trying to navigate the debris choked aisle. So in the end, eight passengers on flight 1482 died in the crash while 10 people were seriously injured and 26 suffered minor injuries. The DC9 was completely destroyed while the Boeing 727 was eventually repaired and returned back to service where it remained until its retirement in 2007. The NTSB found that the primary cause of the accident was poor crew coordination on the DC9 due to the captain's failure to exercise leadership and the first officer's overconfidence in his own ability to navigate the airport. And both pilots eventually ended up losing their jobs as a result of this accident. Contributing factors also included the ground controller’s failure to react to the possible runway incursion in a timely manner and his inadequate taxi instructions. the controllers’ improper visibility observations, inadequate supervision by the tower supervisor, deficient markings and signage on the taxiways, and the failure of Northwest Airlines to provide its crews with any CRM training. The improper maintenance of DC9's talon exit also contributed to number of fatalities, and this whole terrible story eventually led to numerous safety improvements in the industry. The FAA issued an air wordiness directive requiring regular inspections of the DC9's tail exit doors and instructed Macdonald Douglas to redesign the handle which they then obviously did. The FAA then also ordered the closure of taxiway Oscar 4, which was eventually removed entirely to make the intersection less confusing. And on top of that, Detroit airport also took many other corrective actions, including improving the runway lighting control switch, repainting taxiway center line markings with reflective paint, installing more edge lights along runway 03 center, and creating a program to proactively identify and fix faded or misleading markings. Northwest Airlines soon introduced CRM training and also updated its low visibility taxi guidelines to emphasize that the taxi route must be briefed before the aircraft starts moving. In its conclusions, the NTSB wrote that they were concerned by the lack of technological backup systems to help air traffic controllers manage aircraft maneuvering on an airport surface, warning that a single mistake by a controller or pilot could lead to another collision. Today, this problem has been rectified at most major airports thanks to several solutions, including advanced airport surface detection systems who enhance controller’s awareness and generate alarms whenever a runway incursion is detected. Major airports also now have illuminated stop bars at every intersection between a taxiway and a runway, which shows red if the runway is unsafe to cross. And the controllers can now also in many cases selectively illuminate green taxiway center line lights to clearly show the cleared taxi route. But I think that the most important takeaway from this accident is that taxiing needs to be done with the utmost care. And if you get lost, don't ever try to get back on track by yourself. Stop and ask for assistance. There's absolutely no shame in doing that.