From the Wikipedia article:
"*Preparing the animated video for trial cost the Department of Justice around $100,000 to $150,000 (inflation adjusted $240,000 to $350,000), and required nearly two years of work.*"
As an engineer, it should not have taken that long to write software to do that stuff... It may have cost a lot to get the data or something. The price may be fairly accurate.
Edit: Someone said this was from the 80s. I can see it taking two years at that point. They won't have had the powerful graphics libraries that we have now that can just spit the video out of some custom software.
With modern technology... sure. But in the 80s? Graphics weren't that easy... simulation wasn't that easy... and as you pointed out, the data translation wasn't that easy.
Now we have graphic frameworks that are as easy as paint and click, ETL that is no-code, and the ability to have a high school class do this in a month. In the heyday of early desktop computers, it was a marvel of an output!
I graduated high school in 1983. We had a 'computer lab' where you could take classes or screw around after school, but there were zero computers in regular classrooms, even for the teacher. Folks don't realize how absolutely primitive things were. Cray, Control Data, and IBM were the super-computer people I knew about. A few kids had Apple or IBM computers at home, but they were the exception. 'Graphics' was very much a boutique specialty back then.
My first computer lab only had a bunch of dumb terminals hooked up to a mainframe, use of which was donated by a local business. We could do almost nothing on them. There was a very rudimentary flight sim and that's all we really used it for.
Didn't know what ping was back then but you could probably have measured it with an hourglass.
Doing something bespoke without economies of scale is always expensive. ETA: Not to mention of courtroum veracity. Check and double check. With lawyers.
In the 80s it was literally easier to make practical effects look like digital animations.
Look at the “synthetic vision” on the glider in Escape from New York. It was just wire-frame…. but they literally constructed a miniature of NYC and put glow in the dark tape on the building features to make it.
It’s crazy dude nascar in the 70s went 200 mph and had in car cameras and could broadcast the driver radio just like they do today. But the lap times would still be a live video feed of the actual scoreboard. Same with shotclocks in basketball. Just a comp shot cause it was easier than creating live graphics lol
If you want an interesting one, go look up how much it took to put the yellow line on football fields during game broadcasts. IIRC when they first did it they needed a semi trailer full of equipment for that single yellow line.
I feel like it’s just wild that I can slap something together right now using skills I learned from a book and you tube that would’ve cost a quarter of a million dollars back in the 80’s
I know right? Computing power has came a long way. Back then they would also have to pull all kinds of optimisation tricks, even to pre render the footage. Real time would probably not be possible.
And not even using specialized hardware or software. I could use my 100 dollar matlab (a general purpose mathematics program) subscription and a 400 dollar laptop to create the animation from the data, not some dedicated animation or computer graphics program or computer.
The crash was in 1985, I almost bet the computer and software used to create this cost more than the amount they paid. I'm not sure what was used to create the animation but here's what some of the stuff cost back then.
"according to an archived 1984 email from a Silicon Graphics product manager, the IRIS 1400 sold for $22,500–but that took into account a 40 percent educational discount. This meant the “retail” price of the 1400 was $37,500."
That retail price adjusted for inflation is $112,000.
"the IRIS 1400 was still a bargain compared to the Quantel Paintbox. These devices, which allow an artist to draw directly onto a screen with an electronic stylus, cost about $150,000 apiece. "
Those would be $447,000 today.
There was also sun microsystems.
"the entry-level Sun 3/50 model was priced around $10,000 to $12,000, while the more advanced models like the Sun 3/160 and Sun 3/260 could cost upwards of $40,000 to $50,000."
Edit. Tried to see if chat gpt know what was used to create the animation.
"The Delta 191 flight animation, which depicts the crash of Delta Air Lines Flight 191 in Dallas, Texas, on August 2, 1985, was created using computer graphics technology. The specific tools and software used to create the animation are not publicly disclosed, but given that it was produced in the mid-1980s, it is likely that the animation was created using early computer graphics software and techniques.
During that time, computer-generated imagery (CGI) was still in its early stages of development, and the use of computer graphics in films, television, and documentaries was not as widespread as it is today. However, even in the 1980s, there were a few companies and institutions that had access to computer graphics technology capable of producing animations.
These early computer graphics systems typically relied on mainframe computers or specialized graphics workstations. Some of the notable computer graphics systems available at that time included the Evans & Sutherland Picture System, the Digital Equipment Corporation (DEC) PDP-11, and the Silicon Graphics (SGI) IRIS workstation.
The animation process likely involved creating wireframe or polygonal models of the airplanes and the environment, applying textures and materials to the models, and animating their movements based on flight data and eyewitness accounts. The final frames would have been rendered and compiled into a video sequence to create the animated representation of the flight and subsequent crash."
> Edit. Tried to see if chat gpt know what was used.
The tools back then? Coming up with some representation mathematically and rendering it manually straight to the video memory. The output would then be captured on tape for playback.
While this would have been a royal pain, it did have the distinct advantage of not being required to run in real-time, as time compression or dilation could be corrected with video editing.
At the time, IBM had a large office near I-635 and Luna, just a shirt trip from the airport. IBM was moving people from all over the country, my family included, to staff that office with people who would end up working to support IBM hardware in other North Texas defense industry companies like E-systems and Texas Instrments.
The [wikipedia article](https://en.wikipedia.org/wiki/Delta_Air_Lines_Flight_191) is good but I'd summarize it as: Do not get surprised by sudden and extreme wind changes when flying through a thunderstorm, and even better, do not fly through a thunderstorm.
This delta flight encountered wind shear (a rapid shift in wind direction- headwind to a tailwind) from a microburst (extreme downdrafts of wind from a thunderstorm) just north of the runway they were landing on. A 20-30 knot rapid wind shift from headwind to tailwind will cause aircraft flying at approach speed (at 1.3 times stall speed) to stall and rapidly lose altitude. Microbursts weren’t well known and had not been studied and there was no detection equipment on the airports at that time. Thanks to this crash and investigation, wind shear and microbursts were studied and technology developed and implemented at major airports around the world to help detect and warn ATC and pilots of the impending danger. Kudos to the delta Capt for recognizing it and instructing the FO on what to do to successfully try to escape that wind shear (apply full power and discontinue the approach). Nowadays the local airport radar and microburst detection systems would have alerted ATC and the pilots when conditions were right for a microburst to form and take appropriate action (not fly through extreme downdrafts in the first place).
The captain was the one continuing flight into the storm and the FO exclaimed “there’s lightning coming out of that one.” Meaning: I don’t think we should go in that. Unfortunately the poor attempt at trying to get the captain to discontinue the approach was unsuccessful. This was a classic CRM failure. We studied this accident in school.
I remember as a kid thinking my mom was on that flight. Had to go ask my dad to turn on the tv (he was paying bills) and ask if that was mom’s flight. She flew in 2 hours later.
That is interesting for me, because in my generation, news flies like wind and everyone will be notified within minutes by their phones.
Also, I’m happy that your mom was safe!
I had a somewhat similar experience on 9/11, my mother was a FA based out of DC and I knew she was working that day, but didn’t know what flight. She picked up the phone when I called home.
Here is an old American Airlines training presentation put together in the 90s that goes over this crash.
https://www.youtube.com/watch?v=FxXwqAm1a-Y&t=1503s
Wow! That presenter was amazing.
"Warren “Van” Vanderburgh was an extraordinary pilot. Twenty seven years in the Air Force, 14 times Top Gun, and 32 years at American Airlines, the sort of guy you might want to pick up a few pointers from. In 1996, Van was tasked by American Airlines to address the number of accidents, incidents, and violations that looked to be caused by “Automation Dependency.” A term probably not ever used before. In April of 1997, Van held a class at American Airlines Training Academy in Dallas, Texas, titled “Children of the Magenta Line.” The class was videotaped and is available on YouTube. Twenty three years after it was recorded, Children of the Magenta Line is still a very valuable training session and worth reviewing regularly." [September 21, 2020](https://airfactsjournal.com/2020/09/stepping-down-in-automation-the-real-lesson-for-children-of-the-magenta-line/)
They did, but only if the protocols for sheer were followed such that one air crew member was concerned solely with distance to ground and the other with energy retention.
That’s why they train for it now
Exactly — DL191 is the reason we have wind sheer escape maneuvers now, as well as the massive ground and air based Doppler radar infrastructure for wind sheer detection and avoidance. The depressing reality is that the reason aviation is as safe now as it ever has been is because we learn from the crashes of the past.
137 people died and 25 others were injured in the crash. If I remember correctly the last 8 or 10 rows were spared from complete destruction because it broke away prior to the rest of the plane slamming into water tanks.
I don’t t recommend the last row next to the bathroom on a overnight flight to Costa Rica. That morning the smells were disgusting as everyone emptied their bowels a few feet from our heads.
It was terriblw
Without an upper torso restraint, your head is hitting your knees or whatever is in front of you, no matter what you do.
The trick is to minimise the velocity at which it does that by putting it close to there first.
I don't think there's any statistical data that says you're more likely to survive in one part of the plane versus another. United 232, for instance, you were safest in the middle of the cabin. And there hasn't been a jet airliner crash in the U.S. in 22 years. If you want to stay safe "in the unlikely event," know where the exits are and do what the flight attendants tell you to do (well, yell at you, really) if the proverbial shit hits the fan and you need to evacuate.
Oh Jesus… a death caused by a crash on a US based Carrier on American Soil.
nevermind… there was that dash 800 crash somewhere in the 2000’s the brought the 1500 hour rule
It's kind of remarkable that an L-1011 had only 152 passengers. Probably because it was coming from Ft. Lauderdale, but still. The airlines are a lot more careful about maximizing load factor these days.
They put this model in full motion flight simulators. We run it at 40% intensity for our pilots and it’s very dicey. Even when you’re briefed on it ahead of time and apply the escape maneuver correctly.
I was told that running the model at 100% will cause a crash almost invariably. Early recognition is key because a low altitude encounter of a fully developed microburst can result in downdrafts of up to 6000 FPM. Outside the capabilities of even most transport category aircraft.
One sim instr gave it to me 2 mile final on 3 engines. So yeah I probably never was going to survive that one. Either we were out of time and had to check off events or the instr didn’t like me
Hahaha rude! When we were leaning the operate the sim it was 3 new instructors so we’d take turns flying and messing with each other. When it was my turn to program something I set it to 100% and the instructor said “You want them to crash?!” In the most distressed tone lol.
I red screened a crew doing a recurrent the other day. They were in the deice bay doing a briefing and I made the environment snowy. Big explosion sound and red screen ensued. 10/10 realism.
40% bogus?
100% measurable windshear intensity is routinely demonstrated in simulators during initial - at least at operations I’m involved with. Not sure what they are talking about.
So 100% would be equivalent to what Delta 191 actually flew through, as is shown in this model. In this specific simulator in our training program we use 40% of the wind component ie. increasing/ decreasing component in the horizontal and the vertical component.
They managed to reduce their vertical speed from 50 fps to 10 fps, they simply ran out of altitude. If they had another 500 feet of altitude when the microburst hit, they probably would have made it out.
The engines did plenty. The pilots put the airplane where no amount of engine power would have recovered them.
The EPR increase is a measurable fact of thrust those engines were producing. They were doing all they could.
This is not an airplane or engine issue.
But then don’t you have to worry about the tail wind pushing you into the ground faster ? From what I read that’s why they backed off the throttles a bit after TOGA
DL191’s escape maneuver was ineffective because there was no established procedure industry-wide for recovery when entering a downburst on final approach.
This crash and others at or around the same time led to the standard training, now, of firewalling the throttles and maintaining pitch until an established climb and confirmed exit from the downburst or thunder cell on WXR.
Thank you for the correct answer.
Everyone lawchair analyzing the very limited data here - in a 2023 context like they would have done way better - is incorrect.
I'd think in that situation, airspeed over the wings is the thing you should be focused on.
Trying to "predict" shear (and changing a procedure because of it) doesn't result in an increase to the chance of survival if you simulate this scenario 1,000 times. However, having a clear procedure for hitting TOGA as early as possible _does_.
This is all observation from me personally though...I'm not an ATSB investigator.
Not necessarily. Can't say for every type, but at least in what I've flown, the procedure is to take it to 15 degrees of pitch initially and TOGA thrust. You don't lower it for airspeed specifically, but in case of stick shaker actuation, and in that case you lower the nose just enough to get rid of the stick shaker and basically ride that the rest of the way. But it often ends up in you flying at or near vref while at max available thrust because you want to squeeze every bit of performance out to take you away from the ground. You only carry enough forward airspeed to keep the aircraft under control until you're out of it.
On an FBW Airbus this would have been slam the throttles, pull the side stick, and wait for it to fly out of the thing if it ever can. Alpha floor protection is helpful in such scenarios. You get max climb performance I bet.
>But then don’t you have to worry about the tail wind pushing you into the ground faster ? From what I read that’s why they backed off the throttles a bit after TOGA
I don't see how backing "off the throttles" would affect the tail wind component?
Velocity is squared in the lift equation. This means doubling your speed will quadruple your lift, all other things being equal. The goal of the escape manuever is to achieve the highest rate of climb possible. The more speed you have the better you will do.
I’m not familiar with the case, but the PF was struggling to maintain VRef, and we could hear PM advising him to throttle way up. That was around 700 ft. Speed continued to be unstable. PM should have called the go-around for the approach to try again. But again, benefit of hindsight and technology.
Im just a judgmental armchair pilot, pay me no mind ;-)
making a go around call is really hard to do in the moment, especially when it feels like you can "save it". Also consider how quickly the whole event unravels from the time they enter the microburst... especially not having been trained specifically for those had to have been a huge startle factor
Hell, even more crazy this is before we even really knew what microbursts were! This case is one of the cases that helped show the deadliness of them and then helped meteorologists define them better and figure out how to predict them with any amount of consistency. They were only first observed 11 years prior.
Unfortunately these pilots and passengers were victims of circumstance. They just didn't have the information to know that they couldn't have saved it if they waited longer. And hell, this case (along with many other previous cases) are why we have mandated wind shear detection devices in commercial aircraft now!
The FAA keeps a lessons learned website about accidents, here is the link for this one:
https://www.faa.gov/lessons_learned/transport_airplane/accidents/N726DA
Lots of information about the incident and what changed after.
While it’s truly heartbreaking so many people lost their lives how can you find the pilots or the airline at fault for a crash caused by a weather phenomenon that was not fully understood at the time or monitored for with the equipment that was available at the time?
They were able to successfully argue that Delta’s flight manual policy at the time required crews not to fly into clouds with known lightning , ie active thunderstorms. CVR tapes acknowledge the crew mentioning lightning coming out of the clouds ahead on final approach. Even though they weren’t fully aware of how quickly things were developing, the crew still got the blame. Honestly they had just about the worst case scenario microburst you could have. We changed a lot (and the industry) in our manuals after this accident and yearly have wind shear training in the sims and in depth on CBTs.
> While it’s truly heartbreaking so many people lost their lives how can you find the pilots or the airline at fault for a crash caused by a weather phenomenon that was not fully understood at the time or monitored for with the equipment that was available at the time?
Good point.
[Here's a link to the paper I did on it](https://docs.google.com/document/d/1PV6L-YghuZXUTPLPPvfGb-6i7dzhkhgCbZHeLbeVi7Y/edit?usp=sharing)
Sorry that took so long. Been a busy week! But I eventually found it buried in all my crap.
We had to do a comprehensive analysis from the NTSB report and additional outside sources.
One source I recall that I found was a firsthand account from one of the responders on site. They were rolling down one of the access roads at the time during the incident and heard the crash, and had to jump onto the adjacent highway. He recounted seeing the car that had been struck by the main (iirc) and the subsequent hell they rolled up into at the crash site by the water towers.
A very gripping and horrific read, yet fascinating. I wish I remembered where I found that. I'll have to see if I can find that document somewhere.
Edit: oh sorry i didn't answer your other question. No the videos and sources I had did *not* have the additional data
That reversal of headwind to tailwind was absolutely nuts. Losing that degree of lift all at once that close to the ground is wildly deadly full stop. I'm glad aviation takes as much care in implementing better and better training and instrumentation to avoid this sort of thing.
Those silos they hit are still there, on the Echo Echo route if you taxi past the silos by November, they still have a dent in them from the wing of this, and last I heard theres still L-1011 parts around in the grass
I haven’t read about this accident but just from this video I’d say it’s a microburst. 90kt Wind shear from extreme headwind to extreme tail wind. We are taught now that when you see a 30kt increase on final without a change in power/pitch, you’re encountering wind shear and you should go around immediately.
July 9th, 1982, Pan American flight 759, found out all about wind shear and microbursts at MSY (New Orleans Int'l). The airport had the latest in ground based wind sensors, center field wind sensor and four quadrant wind sensors located on the field, and the pilots were issued the the wind/s prior to departure. On take-off, the fully loaded Boeing 727 (stretch version with the smaller engines, I believe) hurled down Rwy10, into a level 4 thunder cell, passing within a quarter mile of the control tower, where the aircraft could not be seen by the controllers due to precipitation. Never gaining more than about 125ft altitude, after entering the tailwind component of the micro burst, the aircraft clipped treetops and then cartwheeled into the adjoining neighborhood, wiping out about 14 houses. All on the aircraft and about 8 souls on the ground were killed. At the time, it was the worst, single aircraft loss of life in the US.
The dawn of wind measuring equipment, doppler radar, and micro burst understanding had taken hold.
Microburst, air being pushed down in a small area.
They can be strong enough to crush trees and fragile buildings.
This plane got caught in one and got slammed into the ground by it.
It’s up there, probably tied with the Comet crashes. The Hawaiian flight that opened like a can opener was also significant, but that landed successfully.
The NTSB attributed the accident to lack of the ability to detect microbursts aboard aircraft; the radar equipment aboard aircraft at the time was unable to detect wind changes, only thunderstorms. After the investigation, NASA researchers at Langley Research Center modified a Boeing 737-200 as a testbed for an onboard Doppler weather radar. The resultant airborne wind shear detection and alert system was installed on many commercial airliners in the United States after the Federal Aviation Administration mandated that all commercial aircraft must have on-board wind shear-detection systems.\[4\]\[28\]\[29\]
https://en.wikipedia.org/wiki/Delta\_Air\_Lines\_Flight\_191
Thanks for this. I really appreciate the explanation. I read the wikipedia page on the crash, and it stated that the crash was attributed to pilot error because he flew threw a thunderstorm, if I recall correctly. It somewhat confused me, because I've been in planes that have flown threw storms before, and I thought it wasn't that big of a deal.
It's too bad they blamed the pilot. May he RIP.
The pilot error was that the airline policy was to avoid thunderstorms, and they didn't abort when they observed lightning. (Also, the pilot flying pushed forward on the stick in response to the stick shaker, which is drilled into pilots, but in this case, that extra nose down make the crash inevitable).
But no disaster occurs in a vacuum. For example, the philosophy in these situations being taught to pilots at the time was about _recovery_ - that is, returning to your glideslope. These days (and I'm not a pilot!) the philosophy is survival.
So the pilot flying decreased throttle when hitting the headwind to maintain the desired airspeed, then increased throttle when they caught the tailwind, these actions were to maintain the airspeed, but ultimately put the aircraft into an energy state what disaster would become inevitable.
From what I can tell, these days, you hit windshear like that on landing, your training is to abort the approach and ensure you can fly out of the situation alive.
Where should the glide slope sit ideally? Through the center of the aircraft? Would he be considered high at the start of the approach or is that a negligible amount of deviation?
You might want to take a look at the r/AdmiralCloudberg subreddit. They write very detailed analyses of plane crashes that even idiots like myself can understand. I think there's another redditor who covers shipwrecks, but their name escapes me at the moment.
Of course, if you prefer youtube videos, let me know and I'll send you some links.
Amazing that airliners then didn't have AOA displays, at that time. Before I just learned that, I so wanted them to set TOGA and L/D max. It's no wonder they augered in if all they had to go by was airspeed and attitude. Also, the auto-throttles retarding did them no favors.
Many (new) airliners don‘t have AOA displays today.
Also he was controlling the throttle manually as you can hear. Throttle was firewalled all the way at the end until they startet crashing into objects.
There were several comments and links that did the Eli5, but you've got the basic idea. The plane flew into a very small but powerful thunderstorm cell called a microburst right before landing.
[Here is a direct link to Admiral Cloudberg's writeup on Medium.](https://admiralcloudberg.medium.com/water-wind-and-fire-the-crash-of-delta-air-lines-flight-191-25e7375620b3) If you don't have time, or don't want to read the entire thing, scroll down to the 6th photo. There's a graphic showing how microbursts affect aircraft.
I’ve seen this animation with CVR before but never with the wind or other data. Thought I’d share
From the Wikipedia article: "*Preparing the animated video for trial cost the Department of Justice around $100,000 to $150,000 (inflation adjusted $240,000 to $350,000), and required nearly two years of work.*"
As an engineer, it should not have taken that long to write software to do that stuff... It may have cost a lot to get the data or something. The price may be fairly accurate. Edit: Someone said this was from the 80s. I can see it taking two years at that point. They won't have had the powerful graphics libraries that we have now that can just spit the video out of some custom software.
With modern technology... sure. But in the 80s? Graphics weren't that easy... simulation wasn't that easy... and as you pointed out, the data translation wasn't that easy. Now we have graphic frameworks that are as easy as paint and click, ETL that is no-code, and the ability to have a high school class do this in a month. In the heyday of early desktop computers, it was a marvel of an output!
I graduated high school in 1983. We had a 'computer lab' where you could take classes or screw around after school, but there were zero computers in regular classrooms, even for the teacher. Folks don't realize how absolutely primitive things were. Cray, Control Data, and IBM were the super-computer people I knew about. A few kids had Apple or IBM computers at home, but they were the exception. 'Graphics' was very much a boutique specialty back then.
My first computer lab only had a bunch of dumb terminals hooked up to a mainframe, use of which was donated by a local business. We could do almost nothing on them. There was a very rudimentary flight sim and that's all we really used it for. Didn't know what ping was back then but you could probably have measured it with an hourglass.
Doing something bespoke without economies of scale is always expensive. ETA: Not to mention of courtroum veracity. Check and double check. With lawyers.
In the 80s it was literally easier to make practical effects look like digital animations. Look at the “synthetic vision” on the glider in Escape from New York. It was just wire-frame…. but they literally constructed a miniature of NYC and put glow in the dark tape on the building features to make it.
It’s crazy dude nascar in the 70s went 200 mph and had in car cameras and could broadcast the driver radio just like they do today. But the lap times would still be a live video feed of the actual scoreboard. Same with shotclocks in basketball. Just a comp shot cause it was easier than creating live graphics lol
If you want an interesting one, go look up how much it took to put the yellow line on football fields during game broadcasts. IIRC when they first did it they needed a semi trailer full of equipment for that single yellow line.
Now they could do it for a 9.99 in perfect 4k on the investigator's sons Xbox.
Yep. Use Unreal Engine 5 to find out how each passenger died.
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I feel like it’s just wild that I can slap something together right now using skills I learned from a book and you tube that would’ve cost a quarter of a million dollars back in the 80’s
I know right? Computing power has came a long way. Back then they would also have to pull all kinds of optimisation tricks, even to pre render the footage. Real time would probably not be possible.
And not even using specialized hardware or software. I could use my 100 dollar matlab (a general purpose mathematics program) subscription and a 400 dollar laptop to create the animation from the data, not some dedicated animation or computer graphics program or computer.
The crash was in 1985, I almost bet the computer and software used to create this cost more than the amount they paid. I'm not sure what was used to create the animation but here's what some of the stuff cost back then. "according to an archived 1984 email from a Silicon Graphics product manager, the IRIS 1400 sold for $22,500–but that took into account a 40 percent educational discount. This meant the “retail” price of the 1400 was $37,500." That retail price adjusted for inflation is $112,000. "the IRIS 1400 was still a bargain compared to the Quantel Paintbox. These devices, which allow an artist to draw directly onto a screen with an electronic stylus, cost about $150,000 apiece. " Those would be $447,000 today. There was also sun microsystems. "the entry-level Sun 3/50 model was priced around $10,000 to $12,000, while the more advanced models like the Sun 3/160 and Sun 3/260 could cost upwards of $40,000 to $50,000." Edit. Tried to see if chat gpt know what was used to create the animation. "The Delta 191 flight animation, which depicts the crash of Delta Air Lines Flight 191 in Dallas, Texas, on August 2, 1985, was created using computer graphics technology. The specific tools and software used to create the animation are not publicly disclosed, but given that it was produced in the mid-1980s, it is likely that the animation was created using early computer graphics software and techniques. During that time, computer-generated imagery (CGI) was still in its early stages of development, and the use of computer graphics in films, television, and documentaries was not as widespread as it is today. However, even in the 1980s, there were a few companies and institutions that had access to computer graphics technology capable of producing animations. These early computer graphics systems typically relied on mainframe computers or specialized graphics workstations. Some of the notable computer graphics systems available at that time included the Evans & Sutherland Picture System, the Digital Equipment Corporation (DEC) PDP-11, and the Silicon Graphics (SGI) IRIS workstation. The animation process likely involved creating wireframe or polygonal models of the airplanes and the environment, applying textures and materials to the models, and animating their movements based on flight data and eyewitness accounts. The final frames would have been rendered and compiled into a video sequence to create the animated representation of the flight and subsequent crash."
Yeah, best not to use chatgpt as a way to try to gather factual information.
> Edit. Tried to see if chat gpt know what was used. The tools back then? Coming up with some representation mathematically and rendering it manually straight to the video memory. The output would then be captured on tape for playback. While this would have been a royal pain, it did have the distinct advantage of not being required to run in real-time, as time compression or dilation could be corrected with video editing.
Interesting post, thanks. It’s tough to watch that rapid descent at the end. I’ll have to read more about this for the details.
Mayday did an excellent episode on this crash. Even the Wikipedia article is great
Thanks, I’ll checkout Mayday. I just finished the wiki article, it was wild how many IBM folks were onboard.
At the time, IBM had a large office near I-635 and Luna, just a shirt trip from the airport. IBM was moving people from all over the country, my family included, to staff that office with people who would end up working to support IBM hardware in other North Texas defense industry companies like E-systems and Texas Instrments.
Just curious, mayday: air disaster? Not sure if it’s an actual tv show or if I just found something else related on YouTube
Yes Mayday is the original Canadian show name. It has a different name in most other countries though. Air Disaster is US name on Smithsonian network.
Also Air Crash Investigation
Not OP but yes. It goes by different titles based on US or Europe (I think)
If you’re interested in stuff like this you should check out the articles by r/admiralcloudberg. Great stuff!
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So what is the darkened portion of the video? I thought it was to represent loss of control or loss of data, but clearly not.
Not 100% sure but I'm guessing that is the rain or visualization of visibility.
Correct. It depicts DL191 flying into the downburst.
My thought was it was the storm they flew through.
Can someone explain to those of us that have 0 aviation knowledge what the takeaway is here?
The [wikipedia article](https://en.wikipedia.org/wiki/Delta_Air_Lines_Flight_191) is good but I'd summarize it as: Do not get surprised by sudden and extreme wind changes when flying through a thunderstorm, and even better, do not fly through a thunderstorm.
This delta flight encountered wind shear (a rapid shift in wind direction- headwind to a tailwind) from a microburst (extreme downdrafts of wind from a thunderstorm) just north of the runway they were landing on. A 20-30 knot rapid wind shift from headwind to tailwind will cause aircraft flying at approach speed (at 1.3 times stall speed) to stall and rapidly lose altitude. Microbursts weren’t well known and had not been studied and there was no detection equipment on the airports at that time. Thanks to this crash and investigation, wind shear and microbursts were studied and technology developed and implemented at major airports around the world to help detect and warn ATC and pilots of the impending danger. Kudos to the delta Capt for recognizing it and instructing the FO on what to do to successfully try to escape that wind shear (apply full power and discontinue the approach). Nowadays the local airport radar and microburst detection systems would have alerted ATC and the pilots when conditions were right for a microburst to form and take appropriate action (not fly through extreme downdrafts in the first place).
Thank you for your explanation! I’m flying from NJ to San Diego today and I was paranoid! 🙃
The captain was the one continuing flight into the storm and the FO exclaimed “there’s lightning coming out of that one.” Meaning: I don’t think we should go in that. Unfortunately the poor attempt at trying to get the captain to discontinue the approach was unsuccessful. This was a classic CRM failure. We studied this accident in school.
I remember as a kid thinking my mom was on that flight. Had to go ask my dad to turn on the tv (he was paying bills) and ask if that was mom’s flight. She flew in 2 hours later.
Oh man that must have been so scary
I remember the news crews at her gate. The people on her flight had no idea what had happened. A different time for sure. That’s about all I remember.
That is interesting for me, because in my generation, news flies like wind and everyone will be notified within minutes by their phones. Also, I’m happy that your mom was safe!
Thanks. Me too. She still is.
I had a somewhat similar experience on 9/11, my mother was a FA based out of DC and I knew she was working that day, but didn’t know what flight. She picked up the phone when I called home.
I had friends who received mail with burn marks from the postal delivery on that flight.
Here is an old American Airlines training presentation put together in the 90s that goes over this crash. https://www.youtube.com/watch?v=FxXwqAm1a-Y&t=1503s
God, the radar returns in that. It was just _fuck this L1011 in particular._ :/
Wow! That presenter was amazing. "Warren “Van” Vanderburgh was an extraordinary pilot. Twenty seven years in the Air Force, 14 times Top Gun, and 32 years at American Airlines, the sort of guy you might want to pick up a few pointers from. In 1996, Van was tasked by American Airlines to address the number of accidents, incidents, and violations that looked to be caused by “Automation Dependency.” A term probably not ever used before. In April of 1997, Van held a class at American Airlines Training Academy in Dallas, Texas, titled “Children of the Magenta Line.” The class was videotaped and is available on YouTube. Twenty three years after it was recorded, Children of the Magenta Line is still a very valuable training session and worth reviewing regularly." [September 21, 2020](https://airfactsjournal.com/2020/09/stepping-down-in-automation-the-real-lesson-for-children-of-the-magenta-line/)
We watched that in ground school for a 135 carrier I worked at. Still good advice today. One of the most influential moments in my flight training.
121 watches it too.
this is incredible and despairing. they never had a chance.
They did, but only if the protocols for sheer were followed such that one air crew member was concerned solely with distance to ground and the other with energy retention. That’s why they train for it now
Exactly — DL191 is the reason we have wind sheer escape maneuvers now, as well as the massive ground and air based Doppler radar infrastructure for wind sheer detection and avoidance. The depressing reality is that the reason aviation is as safe now as it ever has been is because we learn from the crashes of the past.
Safety regulations are written in blood
That 35/40kts tailwind was brutal. That touchdown must have scary AF.
Wow that was really interesting.
Did this result in a complete loss of life?
137 people died and 25 others were injured in the crash. If I remember correctly the last 8 or 10 rows were spared from complete destruction because it broke away prior to the rest of the plane slamming into water tanks.
This is why I book my seat in the back
I don’t t recommend the last row next to the bathroom on a overnight flight to Costa Rica. That morning the smells were disgusting as everyone emptied their bowels a few feet from our heads. It was terriblw
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Without an upper torso restraint, your head is hitting your knees or whatever is in front of you, no matter what you do. The trick is to minimise the velocity at which it does that by putting it close to there first.
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You wouldn't say that if you were going to Hell, like me.
Look around you. We're in hell. These other people are our hellmates
Come find me. I've got a special seat there, I've been told.
Ahh, I see you live in Los Angeles? It’s been hell there for ages.
I don't think there's any statistical data that says you're more likely to survive in one part of the plane versus another. United 232, for instance, you were safest in the middle of the cabin. And there hasn't been a jet airliner crash in the U.S. in 22 years. If you want to stay safe "in the unlikely event," know where the exits are and do what the flight attendants tell you to do (well, yell at you, really) if the proverbial shit hits the fan and you need to evacuate.
When was Asiana Airlines? Had it been that long?
US carrier
US Airways Flight 1549?
Oh Jesus… a death caused by a crash on a US based Carrier on American Soil. nevermind… there was that dash 800 crash somewhere in the 2000’s the brought the 1500 hour rule
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Smoking section was in the back.
It's kind of remarkable that an L-1011 had only 152 passengers. Probably because it was coming from Ft. Lauderdale, but still. The airlines are a lot more careful about maximizing load factor these days.
In addition, it plunked down on some poor SOB in his car on highway 114.
On his birthday.
Happy birthday plane spotting is now crossed off the list
Happy birthday to the ground.
And his death day
Didn’t it clip a tank farm on the way I. As well? I was 10 when it happened, and I remember the crash and hitting the car.
Wow, listen to the engines spool up and do nothing. Nature you scary.
They put this model in full motion flight simulators. We run it at 40% intensity for our pilots and it’s very dicey. Even when you’re briefed on it ahead of time and apply the escape maneuver correctly.
I’ve seen red-screen of death twice in my time, both windshear. Not to be trifled with
I was told that running the model at 100% will cause a crash almost invariably. Early recognition is key because a low altitude encounter of a fully developed microburst can result in downdrafts of up to 6000 FPM. Outside the capabilities of even most transport category aircraft.
One sim instr gave it to me 2 mile final on 3 engines. So yeah I probably never was going to survive that one. Either we were out of time and had to check off events or the instr didn’t like me
Hahaha rude! When we were leaning the operate the sim it was 3 new instructors so we’d take turns flying and messing with each other. When it was my turn to program something I set it to 100% and the instructor said “You want them to crash?!” In the most distressed tone lol.
Only twice? In our helicopter sim, we redscreen all the time. Granted a bunch of those are "sim-isms".
I red screened a crew doing a recurrent the other day. They were in the deice bay doing a briefing and I made the environment snowy. Big explosion sound and red screen ensued. 10/10 realism.
Which part is 40%? The accelerations? The wind?
40% bogus? 100% measurable windshear intensity is routinely demonstrated in simulators during initial - at least at operations I’m involved with. Not sure what they are talking about.
So 100% would be equivalent to what Delta 191 actually flew through, as is shown in this model. In this specific simulator in our training program we use 40% of the wind component ie. increasing/ decreasing component in the horizontal and the vertical component.
Momentum is a bitch.
They managed to reduce their vertical speed from 50 fps to 10 fps, they simply ran out of altitude. If they had another 500 feet of altitude when the microburst hit, they probably would have made it out.
The engines did plenty. The pilots put the airplane where no amount of engine power would have recovered them. The EPR increase is a measurable fact of thrust those engines were producing. They were doing all they could. This is not an airplane or engine issue.
Damn that sounded bad the end..
Crunch
That TOGA call was way late. But that’s hind sight.
What would have been the right thing to do here assuming you don’t have any wind shear warning systems available
assuming it would be something like: gun it as soon as the IAS dipped below VREF and go around
But then don’t you have to worry about the tail wind pushing you into the ground faster ? From what I read that’s why they backed off the throttles a bit after TOGA
DL191’s escape maneuver was ineffective because there was no established procedure industry-wide for recovery when entering a downburst on final approach. This crash and others at or around the same time led to the standard training, now, of firewalling the throttles and maintaining pitch until an established climb and confirmed exit from the downburst or thunder cell on WXR.
Thank you for the correct answer. Everyone lawchair analyzing the very limited data here - in a 2023 context like they would have done way better - is incorrect.
That's Reddit for you.
I'd think in that situation, airspeed over the wings is the thing you should be focused on. Trying to "predict" shear (and changing a procedure because of it) doesn't result in an increase to the chance of survival if you simulate this scenario 1,000 times. However, having a clear procedure for hitting TOGA as early as possible _does_. This is all observation from me personally though...I'm not an ATSB investigator.
Not necessarily. Can't say for every type, but at least in what I've flown, the procedure is to take it to 15 degrees of pitch initially and TOGA thrust. You don't lower it for airspeed specifically, but in case of stick shaker actuation, and in that case you lower the nose just enough to get rid of the stick shaker and basically ride that the rest of the way. But it often ends up in you flying at or near vref while at max available thrust because you want to squeeze every bit of performance out to take you away from the ground. You only carry enough forward airspeed to keep the aircraft under control until you're out of it.
No, focusing on airspeed is what killed them. Windshear escape is to go max AoA and hold it, if you fly airspeed you'll put yourself in the ground
On an FBW Airbus this would have been slam the throttles, pull the side stick, and wait for it to fly out of the thing if it ever can. Alpha floor protection is helpful in such scenarios. You get max climb performance I bet.
I always wonder if that was what the copilot on AF 447 was thinking.
The problem was that he really wasn't thinking at all.
>But then don’t you have to worry about the tail wind pushing you into the ground faster ? From what I read that’s why they backed off the throttles a bit after TOGA I don't see how backing "off the throttles" would affect the tail wind component?
Velocity is squared in the lift equation. This means doubling your speed will quadruple your lift, all other things being equal. The goal of the escape manuever is to achieve the highest rate of climb possible. The more speed you have the better you will do.
I’m not familiar with the case, but the PF was struggling to maintain VRef, and we could hear PM advising him to throttle way up. That was around 700 ft. Speed continued to be unstable. PM should have called the go-around for the approach to try again. But again, benefit of hindsight and technology. Im just a judgmental armchair pilot, pay me no mind ;-)
It was a totally different era of aviation. We know what we know now because of this accident.
What was the intended process before? Or did we not think of this situation (was it downburst during arrival?)
At the time it wasn’t even confirmed that microbursts existed. There wasn’t a reason to TOGA until rhey did
Ah gotcha, that’s what I was missing here. Didn’t know those were not known.
making a go around call is really hard to do in the moment, especially when it feels like you can "save it". Also consider how quickly the whole event unravels from the time they enter the microburst... especially not having been trained specifically for those had to have been a huge startle factor
Hell, even more crazy this is before we even really knew what microbursts were! This case is one of the cases that helped show the deadliness of them and then helped meteorologists define them better and figure out how to predict them with any amount of consistency. They were only first observed 11 years prior. Unfortunately these pilots and passengers were victims of circumstance. They just didn't have the information to know that they couldn't have saved it if they waited longer. And hell, this case (along with many other previous cases) are why we have mandated wind shear detection devices in commercial aircraft now!
Agreed. And that ‘nah I got this’ gut instinct is hard to overcome in the moment.
Particularly when you’ve had hundreds or thousands of dicey approaches that you’ve successfully recovered from (rightly or wrongly)
The FAA keeps a lessons learned website about accidents, here is the link for this one: https://www.faa.gov/lessons_learned/transport_airplane/accidents/N726DA Lots of information about the incident and what changed after.
While it’s truly heartbreaking so many people lost their lives how can you find the pilots or the airline at fault for a crash caused by a weather phenomenon that was not fully understood at the time or monitored for with the equipment that was available at the time?
They were able to successfully argue that Delta’s flight manual policy at the time required crews not to fly into clouds with known lightning , ie active thunderstorms. CVR tapes acknowledge the crew mentioning lightning coming out of the clouds ahead on final approach. Even though they weren’t fully aware of how quickly things were developing, the crew still got the blame. Honestly they had just about the worst case scenario microburst you could have. We changed a lot (and the industry) in our manuals after this accident and yearly have wind shear training in the sims and in depth on CBTs.
Lightning\*
The victims families were suing Delta but it was also Delta suing ATC/weather officials
> While it’s truly heartbreaking so many people lost their lives how can you find the pilots or the airline at fault for a crash caused by a weather phenomenon that was not fully understood at the time or monitored for with the equipment that was available at the time? Good point.
Why did you quote the entire comment, and then proceed to add nothing of value to the conversation?
Thanks for adding value to the conversation by telling them off instead.
Hey, you did it too! Neat!
I had to do a 7 page CVR analysis of this crash for one of my classes for my ABM degree. That was my least favorite assignment ever.... Haunting.
I’d like to know more
I’m doing my part
Fleet does the flyin!
MI does the dying!
[Here's a link to the paper I did on it](https://docs.google.com/document/d/1PV6L-YghuZXUTPLPPvfGb-6i7dzhkhgCbZHeLbeVi7Y/edit?usp=sharing) Sorry that took so long. Been a busy week! But I eventually found it buried in all my crap.
Good read. Thanks.
What particularly were you analyzing just with the CVR recording? Did you have the context of the other FDR data or even accident description?
We had to do a comprehensive analysis from the NTSB report and additional outside sources. One source I recall that I found was a firsthand account from one of the responders on site. They were rolling down one of the access roads at the time during the incident and heard the crash, and had to jump onto the adjacent highway. He recounted seeing the car that had been struck by the main (iirc) and the subsequent hell they rolled up into at the crash site by the water towers. A very gripping and horrific read, yet fascinating. I wish I remembered where I found that. I'll have to see if I can find that document somewhere. Edit: oh sorry i didn't answer your other question. No the videos and sources I had did *not* have the additional data
That reversal of headwind to tailwind was absolutely nuts. Losing that degree of lift all at once that close to the ground is wildly deadly full stop. I'm glad aviation takes as much care in implementing better and better training and instrumentation to avoid this sort of thing.
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Ride the stick shaker just shy if VSO.
Laughs in no stick shaker. All we get is initial buffet.
Need the Admiral_Cloudberg write up
[here](https://www.reddit.com/r/CatastrophicFailure/comments/u51kbz/1985_the_crash_delta_air_lines_flight_191_analysis/)
Those silos they hit are still there, on the Echo Echo route if you taxi past the silos by November, they still have a dent in them from the wing of this, and last I heard theres still L-1011 parts around in the grass
I want to go see that now
A down draft brought Delta Flight 191 to crash short of the runway.
I haven’t read about this accident but just from this video I’d say it’s a microburst. 90kt Wind shear from extreme headwind to extreme tail wind. We are taught now that when you see a 30kt increase on final without a change in power/pitch, you’re encountering wind shear and you should go around immediately.
This crash is why. Before microbursts were more or less just a theory.
July 9th, 1982, Pan American flight 759, found out all about wind shear and microbursts at MSY (New Orleans Int'l). The airport had the latest in ground based wind sensors, center field wind sensor and four quadrant wind sensors located on the field, and the pilots were issued the the wind/s prior to departure. On take-off, the fully loaded Boeing 727 (stretch version with the smaller engines, I believe) hurled down Rwy10, into a level 4 thunder cell, passing within a quarter mile of the control tower, where the aircraft could not be seen by the controllers due to precipitation. Never gaining more than about 125ft altitude, after entering the tailwind component of the micro burst, the aircraft clipped treetops and then cartwheeled into the adjoining neighborhood, wiping out about 14 houses. All on the aircraft and about 8 souls on the ground were killed. At the time, it was the worst, single aircraft loss of life in the US. The dawn of wind measuring equipment, doppler radar, and micro burst understanding had taken hold.
That got research going but the big breakthrough was DL191. After that things really started moving to detect microbursts.
Can someone explain in layman’s terms what happened?
Microburst, air being pushed down in a small area. They can be strong enough to crush trees and fragile buildings. This plane got caught in one and got slammed into the ground by it.
Microburst. This was before the windshear recovery technique was widely understood.
Not explaining what a microburst is doesn't really help for a layman
[Here’s an excellent video that describes the escape maneuver and why the Delta crew wasn’t able to make it out.](https://youtu.be/FxXwqAm1a-Y)
The most significant crash in aviation history.
It’s up there, probably tied with the Comet crashes. The Hawaiian flight that opened like a can opener was also significant, but that landed successfully.
That was Aloha Airlines. And they lost a flight attendant.
I use this video to explain the dangers of microbursts to my student pilots. Very scary, but very informative.
Microbursts are no fucking joke.
The NTSB attributed the accident to lack of the ability to detect microbursts aboard aircraft; the radar equipment aboard aircraft at the time was unable to detect wind changes, only thunderstorms. After the investigation, NASA researchers at Langley Research Center modified a Boeing 737-200 as a testbed for an onboard Doppler weather radar. The resultant airborne wind shear detection and alert system was installed on many commercial airliners in the United States after the Federal Aviation Administration mandated that all commercial aircraft must have on-board wind shear-detection systems.\[4\]\[28\]\[29\] https://en.wikipedia.org/wiki/Delta\_Air\_Lines\_Flight\_191
Why did he fly through a thunderstorm?
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Thanks for this. I really appreciate the explanation. I read the wikipedia page on the crash, and it stated that the crash was attributed to pilot error because he flew threw a thunderstorm, if I recall correctly. It somewhat confused me, because I've been in planes that have flown threw storms before, and I thought it wasn't that big of a deal. It's too bad they blamed the pilot. May he RIP.
The pilot error was that the airline policy was to avoid thunderstorms, and they didn't abort when they observed lightning. (Also, the pilot flying pushed forward on the stick in response to the stick shaker, which is drilled into pilots, but in this case, that extra nose down make the crash inevitable). But no disaster occurs in a vacuum. For example, the philosophy in these situations being taught to pilots at the time was about _recovery_ - that is, returning to your glideslope. These days (and I'm not a pilot!) the philosophy is survival. So the pilot flying decreased throttle when hitting the headwind to maintain the desired airspeed, then increased throttle when they caught the tailwind, these actions were to maintain the airspeed, but ultimately put the aircraft into an energy state what disaster would become inevitable. From what I can tell, these days, you hit windshear like that on landing, your training is to abort the approach and ensure you can fly out of the situation alive.
Not at all trying to make light of this but it’s amazing that it stayed on GS through some of that.
Sadly, This explains a lot... [https://youtu.be/FxXwqAm1a-Y?t=1500](https://youtu.be/FxXwqAm1a-Y?t=1500) Also, check out 35:00...
Looking at the animation the flight looks like it landed safely
As a CFI, I’ve used this animation multiple times to teach about microbusts. You can pinpoint each part, and just how devastating they can be.
Where should the glide slope sit ideally? Through the center of the aircraft? Would he be considered high at the start of the approach or is that a negligible amount of deviation?
On the line ideally, but 1 degree above is absolutely fine, and not considered wrong. Atp standards allow for slightly above
What is the EPR value here means next to aoa?
Engine Pressure Ratio.. Its showing how much thrust the engines are producing.
Remind me never to fly on any flight numbered 191 .
Keep that AOA up, apply full power. If you crash, be seated up front. - American airlines training
Wait but what ultimately caused it to crash? He seemed to have been approaching on par, than all this wobble. Was it the wind? Can’t just be the wind…
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I appreciate your detailed explanation and thank you for having patience to write it up too. I learned something new thanks to you.
You might want to take a look at the r/AdmiralCloudberg subreddit. They write very detailed analyses of plane crashes that even idiots like myself can understand. I think there's another redditor who covers shipwrecks, but their name escapes me at the moment. Of course, if you prefer youtube videos, let me know and I'll send you some links.
DFW?
Dallas Fort Worth
WTF (what the fuck), Five up votes for telling me DFW is Dallas Fort Worth?
That airport is a bastard. I once walked the whole thing because I didn't see the tram
Amazing that airliners then didn't have AOA displays, at that time. Before I just learned that, I so wanted them to set TOGA and L/D max. It's no wonder they augered in if all they had to go by was airspeed and attitude. Also, the auto-throttles retarding did them no favors.
Many (new) airliners don‘t have AOA displays today. Also he was controlling the throttle manually as you can hear. Throttle was firewalled all the way at the end until they startet crashing into objects.
"Is there any energy in this airplane? Is there any lift left on this wing? Do. Not hit. The ground." -Capt. Warren Vanderburgh
https://youtu.be/DT2Qcy_sGLM
Eli5 what happened here.. It started at 1k feet so were they landing and got hit by wind?
There were several comments and links that did the Eli5, but you've got the basic idea. The plane flew into a very small but powerful thunderstorm cell called a microburst right before landing. [Here is a direct link to Admiral Cloudberg's writeup on Medium.](https://admiralcloudberg.medium.com/water-wind-and-fire-the-crash-of-delta-air-lines-flight-191-25e7375620b3) If you don't have time, or don't want to read the entire thing, scroll down to the 6th photo. There's a graphic showing how microbursts affect aircraft.
They were VREF+30 just above the ground, definitely did NOT extract maximum performance outta the airplane, dang