This is probably the worst way a plane could go down in terms of damage caused. Maximum effect in term of damage. Cargo plane apparently reached V1 (go/no go speed) on the runway, and suffered a catastrophic engine failure. They passed V1, so they knew they were going down. Engine was shedding large debris, including the housing (!!!) which is a shrapnel shield.
They were on fire just as they reached V1.
Plane was fully loaded with 38,000 LB of fuel for 12 hour flight to hawaii. Worst case scenario.
Pilots did the heroic thing - they tried to take off instead at 160 MPH to minimize collateral damage (highway and warehouses at the end of the runway) and crash and die somewhere else, instead of go beyond the runway at that speed. Accelerating a fully loaded jet plane at ground level beyond the runway has obvious consequences. They had one choice.
Instead, they clipped the UPS factory because they were so low, they tried to clear it but did not. Plane then hit the ground port wing down, shearing it off entirely, smearing a fireball of jet fuel across half a mile (not an exaggeration) before the plane flipped. Crew were likely dead by before this, footage shows the cockpit being slammed into the ground like a mousetrap by the flip once the port wing was gone and gravity took the starboard wing over.
Physics took over. Plane flipped and rolled upon loss of port wing, smearing a rolling fireball of the remaining fuel load from the starboard wing for another half a mile.
Louisville is now a firestorm as a result.
Respect to the flight crew; rest in peace, they made the best they could out of a really shitty scenario. They flew it all the way down.
Standard procedure at V1 is commit to the takeoff and diagnose the problem in-air. Much of your comment is pure speculation until flight data recorders come back, we have no idea what the crew was thinking or what issues they were even aware of.
> they tried to take off instead of accelerate past the runway at ground level
Do runways have some sort of barrier between them and the next "important" thing. It seems like that would be prudent both for cases like this, and breaking failures following landings.
> Do runways have some sort of barrier between them and the next "important" thing. It seems like that would be prudent both for cases like this
Ha, Jeju Air Flight 2216 smashed into a barrier on the second landing attempt in Muan last year [0], and people commented "How could there be a barrier at the end of the runway, so obviously stupid, irresponsible", etc.
Now a plane does not smash into a barrier at the end of the runway and people suggest putting barriers at the end of the runway.
Don't mean to attack parent post, but may I suggest that
a) hordes of experts have thought long and hard about these issues, and it is unlikely that you can encounter this for the first time as a lay person and come up with a solution that has eluded the best engineers for decades ("why don't they attach a parachute to the plane?"), and
b) we are very close to an optimum in commercial aviation, and there are few if any unambiguous ("Pareto") improvements, but rather just tradeoffs. For example: You leave cockpit doors open, terrorists come in and commandeer the plane to turn it into a weapon. You lock the cockpit doors closed, and suicidal pilots lock out the rest of the crew and commandeer the plane to turn it into a weapon of mass-murder-suicide.
One improvement is a bed of concrete at the end of the runway that will catch the wheels and slow an airplane down to a stop. Pretty much everyone agrees it’s a good idea but it’s not always possible due to space needs or cost. https://en.wikipedia.org/wiki/Engineered_materials_arrestor_...
The ramp will need to be very long and very high in order to absorb the momentum of a fully loaded widebody jet. Not something that you'd want near a runway where planes can land in either direction.
Consider the possibility that gigantic flying aluminum tubes filled with tons of flammable fuel hurtling around at hundreds of kilometers per hour comprise a dilemma that has no trivial answers. Even defining what "important thing" means at any given instant is not straightforward.
Unless you have a berm several dozen meters high with a 100 meter base, you ain't stopping something like this from a physics standpoint unfortunately.
Many airports have this problem. The recent korean air disaster which echos this is another example. BTW, this is why most airports, if possible, point out to sea...
Newer airports usually try to have space, that's the only thing helping with the physics involved here.
Older airports might have EMAS [1] retrofitted at the ends to help stop planes, but that's designed more for a landing plane not stopping quickly enough (like [2]) - not a plane trying to get airborne as in this case.
There is a dead zone between rejection and successful take-off speeds. We see it hit too often.
I think pilot training is playing a factor. A normal rotation kills too much energy. One engine can climb when you have some airspeed and get clean, but if you lose too much energy on rotation, the inefficiency of the AoA for the rest of the short flight means that engine can no longer buy you any up. I've seen too many single-engine planes going down while trying to pitch up the whole way down.
So, less aggressive single-engine rotations and energy absorbers at the ends of runways that can't get longer. This seems like the kind of thing where we do it because it removes a significant cause of people dying.
Another crash video shows the aircraft clearly descending before colliding with anything. It manages to go up a bit, so it's fast enough to get airborne. The normal looking rotation kills too much energy. The plane is then too inefficient to maintain speed. AoA goes up while energy goes down. Power available goes negative and then it's over.
Rotation does increase drag, but you need to rotate in order to achieve the necessary angle of attack. The only way to reduce the rotation angle is by going faster than the normal rotation speed for the given weight and airfield density altitude, but doing so is out of the question in this scenario.
> It manages to go up a bit, so it's fast enough to get airborne. The normal looking rotation kills too much energy.
Yes, it did get airborne for a few seconds but from the video below, it looks like the left wing was damaged by the fire and could not provide enough lift, then the right wing rolled the plane to the left causing the crash.
> looks like the left wing was damaged by the fire
The wings and aerodynamics don't really care if air or air with combustion are flowing around them.
Roll is a consequence of the loss of control due to low speed and the yaw of the good engines. Speed up, rudder works, plane might maintain positive climb.
For skin, a few seconds might be significant. For the spars, not nearly enough time to matter. It's also not at cruise speed slamming into a downdraft or anything. This is about a 1G loading. Negligible for a while. While the fire looks cool, there's a lot of free stream mixing in and the temps won't really get that high beyond the cowling.
Some runways have been extended with ‘engineered materials’ surfaces, often a form of porous concrete into which an airliner’s wheels will sink, absorbing a lot of energy and arresting the airplane without causing it to break up. It is very effective for landing overruns, but I don’t know about last-seconds aborted takeoffs.
Security/debris fencing yes, but that's like, orders of magnitude short of what would stop the amount of energy we're talking about here.
You also don't particularly want it to be catastrophically effective as there are real world cases where planes have clipped the fence and then NOT gone on to crash, or at least to crash in a fairly controlled manner with the majority onboard surviving. Hitting a brick wall at 180mph is going to have a 0% survival rate.
Yet a reinforced concrete wall of e.g. triangular section and anchored with "long enough" piles would be about the only not-that-expensive way to turn a short strip of "airport land" past the EMAS into a V1 stopping supermarket.
It depends on whether or not, at the point in which you realize you have an engine on fire, you have room on the runway left to stop.
As I understand it, there is a low speed regime, under 80 knots, where are you stop for basically anything.
Then there is a high speed regime, where you only stop for serious issues, because you now have so much kinetic energy that stopping the plane, while still possible, will involve risk. (i.e. fire from overheated brakes.)
At a certain point, called V1, there’s no longer enough room to stop, no matter what your problem is. You’re either getting airborne or you’re crashing into whatever is ant the end of the runway. In general, getting airborne is the safer option, while obviously still not risk free.
However, this calculation also assumes that the engine fails in an isolated fashion, and its failure did not affect the other engines. If the failure of the left engine threw off debris that damaged the middle engine then we are now talking about a double engine failure. I’m sure the pilots knew there was a problem with the engine when they made the decision to continue, but it’s possible that problems with the middle engine weren’t apparent yet and that it only started to fail once they were committed.
Obviously, this is just speculation, and we will have to wait for the preliminary report at least.
Being untrained but spending a little bit of time in a full motion 737 simulator that’s used to train and certify commercial pilots, I was amazed at how quickly things happen even in a scenario with no faults.
This situation (single engine failure at V1) is something that commercial pilots are certified in at every recurrent certification since it’s one of the most difficult you can be in. The crew now need to climb and go around for a landing on one engine while simultaneously running through the engine failure (and also likely fire) checklist. I don’t know if a double engine failure at V1 on a fully loaded 3 engine aircraft is technically survivable or if it’s something that’s trained on. They were put in an incredibly difficult situation just based on what reports we’ve already seen.
V1 is the speed at which you can still stop the plane before the end of the runway. (It is computed for each takeoff based on runway length, aircraft mass, takeoff engine power setting, flaps, wind, runway condition, etc.)
When the plane reaches V1, pilots take the hand off the throttle: they're committed to takeoff, even if an engine fails. It is better to take off and fix the problem or land again, than to smash into whatever is beyond the end of the runway.
Isn't there any margin? Does it calculate stopping before end of runway or before causing damage?
Surely uncertainty about the situation contributes to defaulting to committing, but what if it's a passenger plane and at V1 pilots know they've lost power?
Wouldn't veering into highway at 30 mph be weighted against certain, big loss of life?
Edit: I now see that this has been partially answered by uncle comment
A fully loaded plane is extremely likely to turn into a fireball if it hits anything on the ground, even at 30mph. It's just a thin shell of aluminum with tons of fuel sloshing inside.
To avoid mass casualties at the end of the runway - on the road, or the buildings that the runway points to. Check the layout on google maps.
More specifically, V1 is the max speed at which you're about to take off, but you can still abort from. They hit that max speed and realized there was a major problem that hypothetically, they could have slowed down from, but realistically was not possible. They had no choice.
The damage on the ground is scary to look at. I think the only silver lining here is that it was "just" a sparser industrial area and there weren't any homes. I'm really curious about what the investigation will reveal in a few months. This doesn't look like a "regular" engine fire from a bird strike or so, you would normally expect the flames to come out the back and not over the wing. And at least in theory the MD-11 should be flyable with just two engines, although flames on a wing is probably "really really bad" just by itself already. Too early to speculate about what happened though.
> And at least in theory the MD-11 should be flyable with just two engines
Flying with two engines and taking off without an engine in a loaded aircraft are two very different things. A lot more thrust is needed during takeoff than after.
Taking off with one engine inoperative (on a multi-engine aircraft, obviously - you aren't going to get anywhere with your only engine gone) is completely normal/within design parameters, albeit undesirable.
In fact, it being normal almost certainly contributed to the scale of this accident, since a single engine failure during the takeoff roll isn't considered enough of an emergency to reject the takeoff at high speed (past a certain speed, you only abort if the aircraft is literally unflyable - for everything else, you take the aircraft & emergency into the air and figure it out there). The crew wouldn't have had any way to know that one of their engines had not simply failed, but was straight-up gone with their wing on fire to boot.
> The crew wouldn't have had any way to know that one of their engines had not simply failed, but was straight-up gone with their wing on fire to boot.
I don't know about the MD-11 itself, but other aircraft from that time period have sensors to detect and report overheat and fire in various parts of the aircraft, including engines and wings.
Well, there's a very big difference between "Engine fire: some of the combustion chamber's heat and flame has breached containment" and, say, "Engine fire: the engine has exploded, catastrophically damaging your wing which is now visibly on fire". However, both things are reported in the cockpit as ENG FIRE.
There's also a very big difference between "Engine failure: something has damaged or jammed enough components that the turbines are no longer spinning fast enough to produce thrust or drive the generators" and "Engine failure: the engine is no longer attached to the aircraft, which is why it is no longer producing thrust". However, both things are reported in the cockpit as ENG FAIL.
(Un)fortunately, cockpit warnings prioritise the what (so to speak) and not the how or why. On one hand, this makes decision-making a lot simpler for the crew, but on the other...well, in rare cases the lack of insight can exacerbate a disaster. Depending on when exactly the engine gave out, this poor crew might have been doomed either way, but they might have been able to minimise collateral damage if they knew just how badly crippled the aircraft was. And there was a very similar accident to this one (actually involving the predecessor of the MD-11, the DC-10), American Airlines 191 - one of the engines detached from the aircraft, damaging the leading edge of its wing in the process, causing that wing to stall when the crew slowed down below the stall speed of the damaged wing in a bid to climb. If they could have somehow known about the damage, the accident might have been avoided entirely as the crew might have known to keep their speed up.
I’m sure they knew there was an issue, but I don’t think the sensors can differentiate between “your engine is on fire, but if you can shut it down quickly, everything will be cool.” and “half your entire wing is on fire and your engine is pouring flame out the front/top instead of the back”
I don't know what the MD-11 would have had, again I didn't work on it. But the systems used for other aircraft would have reported an alarm based on what I saw in the video, at least they were designed to do that. The LRU receiving the sensor inputs wouldn't typically be in the wing and would be able to continue reporting the alarm condition even if the sensors fail. In fact, the lack of current from the sensor (for the systems I worked on) would have been enough to trigger the alarm if the sensor were completely eliminated.
Every multi-engine airliner is designed to be able to take off safely even if an engine fails at a critical moment. What might have happened in this case is that the mechanism of failure of one engine caused damaged or interfered with the operation of another engine (via smoke, debris, etc.), and taking off with two engines degraded is not part of the design criteria.
I specifically remember watching a flight test doing an aggressive takeoff and having the voiceover say that aircraft (two engine) need to have enough power to take off full with one engine. And so can take off very steeply empty with two engines. Would that not also be the case for these planes?
Yes, planes are designed to be able to take off with a lost engine. Usually this will extend the roll a bit because the speeds are different for engine out operations. This isn't the first MD-11 with an engine out take off, 5 years ago a FedEx MD-11 took off with a failure in the left engine[1]. Slightly different case, obviously, but it's certainly something that is accounted for when designing planes.
That being said, depending on how you lose the engine it can really mess up the takeoff; AA191 was lost when an engine detached from the plane on takeoff and took out part of the wing and hydraulic system with it. https://en.wikipedia.org/wiki/American_Airlines_Flight_191
All planes are definitely capable of taking off safely even if they lose an engine at the worst time. Whatever happened here, I would be shocked if lack of thrust in the 2 remaining engines was a significant factor unless someone really screwed up the load calculations and they were overweight for conditions.
I don’t know, that looks like a lot more than just a stall. There was a ton of flame that looked like it was coming out of the front or top of the engine, rather than just something shooting out the back.
I think you're looking at the left wing (number 1) engine; GP is talking about either the tail or right wing engine. (I think tail is number 2 on MD-11.) There's a brief explosion visible through the smoke at about 1-2 seconds in, to the right of the engine visibly on fire; that's probably what he's talking about.
Yup makes sense. Now seeing photos of the entire left engine on the ground by the runway and the implication that however it failed it might have damaged the tail engine.
I would say it does not, in fact, look like a compressor stall. It looks very much like an uncontained disassembly, presumably from fan blades that suffered a catastrophic failure and broke up in a way that exceeded the limits of the engine's containment.
Obviously impossible to tell from some cell phone type videos. Being struck by something is also possible. But it sure does look like an uncontained engine failure.
This is probably the worst way a plane could go down. Maximum effect in term of damage. Cargo plane apparently reached V1 (go/no go speed) on the runway, and suffered a catastrophic engine failure. They passed V1, so they knew they were going down. Engine was shedding large debris, including the housing (!!!) which is a shrapnel shield.
They were on fire just as they reached V1.
Plane was fully loaded with 38,000 LB of fuel for 12 hour flight to hawaii. Worst case scenario.
Pilots did the heroic thing - they tried to take off instead of accelerate past the runway at ground level at 160 MPH to minimize collateral damage (highway and warehouses at the end of the runway) and crash and die somewhere else.
Instead, they clipped the UPS factory because they were so low, they tried to clear it but did not. Plane then hit the ground port wing down, shearing it off entirely, smearing a fireball of jet fuel across half a mile (not an exaggeration) before the plane flipped. Crew were likely dead by then, footage shows the cockpit being slammed into the ground by the flip once the port wing was gone and gravity took the starboard wing over.
Plane flipped, continued to smear half of the fuel load for another half a mile.
> They passed V1, so they knew they were going down.
To know this, they would have to know they had lost multiple engines. Clearly this is the case by the end, but it's not clear who realized what at what time.
Another DC-10/MD-11 crash.
Does UPS perform their own engine maintenance, or do they outsource the work?
What is the effect of the recent layoff of 40,000 and the current cost-cutting project?
Maybe wait with the judgements until the report is in? There are so many possible reasons why this could have happened that have nothing to do with the two items you listed (though it maybe that it does, it is just a bit pointless to assign blame before you know what the cause of the accident was).
This is a silly take because having your ATC workers unpaid for over 30 days is going to increase the risk of catastrophic plane crashes. Even if this had nothing to do with this.
Footage of plane crashes are certainly important to know _this could start happening to passenger planes_
It is also true that the risk of plane crashes goes up when you swap prioritization of ATC workers who attended ATC school for prioritization of those who said they were bad at science on a questionnaire. Nevertheless, it's highly unlikely that you could identify that as a primary cause of any individual crash.
But was un-discoverable? Or un-preventable? Seems plane inspectors and safety-related roles were affected and have been furloughed:
> But for the people involved in inspecting our planes to ensure they follow Federal Aviation Administration safety standards, the situation is more complicated. While principal aviation inspectors were told to keep working, assistant-level inspectors and other support staff were sent home and then had to be recalled.
Of course it was not unpreventable, though it might turn out that preventing it would have been unreasonably expensive.
But, the FAA inspectors are not responsible for making sure planes are safe to fly. They are responsible for making sure the people whose job that actually is, are doing their jobs effectively. That’s a critical difference.
It’s UPS maintenance personnel who are responsible for making sure that UPS planes are safe to fly. Yes, it’s possible that there is some institutional failure at UPS, that could have been caught if FAA inspectors were working in the past 30 days, but this isn’t the most likely scenario, and the root cause and responsibility (in this hypothetical) would still lie with UPS and not the FAA and the shutdown.
Thats kind of insincere given how much safer flying is compared to driving a car. Modern flight is not dangerous, its just more spectacular when failures happen.
À lot of the reason why flying is so safe now is because of the culture of investigating every incident to make sure they won't happen again.
And, unfortunately, it's not that rare that the investigations to turn up things that were the result of corners being cut. I'm guessing that's what the "FAFO" comment points to.
Flying is only safer than driving a car when extremely regular and frequent maintenance is performed and performed correctly. The safety of flying goes down very fast when the maintenance effectiveness goes down. That is not true for cars.
Probably also worth pointing out that flying is only safer for Part 121 operators (airlines) -- private jets, sightseeing helicopters, skydiving operators, and general aviation are all more dangerous.
The maintenance and inspection tends to be done by MROs, and any institutional issue within UPS's MRO would have been identified before the shutdown by the FAA and other regulators.
But based on your comment history, you aren't from the US, have not ever visited America, do not care to visit America, and haven't interacted with Americans, so I doubt you have on the ground experience with the US. But that also leads to the question of why you even care to comment on our affairs if you dislike us to such a degree.
This is probably the worst way a plane could go down in terms of damage caused. Maximum effect in term of damage. Cargo plane apparently reached V1 (go/no go speed) on the runway, and suffered a catastrophic engine failure. They passed V1, so they knew they were going down. Engine was shedding large debris, including the housing (!!!) which is a shrapnel shield.
They were on fire just as they reached V1.
Plane was fully loaded with 38,000 LB of fuel for 12 hour flight to hawaii. Worst case scenario.
Pilots did the heroic thing - they tried to take off instead at 160 MPH to minimize collateral damage (highway and warehouses at the end of the runway) and crash and die somewhere else, instead of go beyond the runway at that speed. Accelerating a fully loaded jet plane at ground level beyond the runway has obvious consequences. They had one choice.
Instead, they clipped the UPS factory because they were so low, they tried to clear it but did not. Plane then hit the ground port wing down, shearing it off entirely, smearing a fireball of jet fuel across half a mile (not an exaggeration) before the plane flipped. Crew were likely dead by before this, footage shows the cockpit being slammed into the ground like a mousetrap by the flip once the port wing was gone and gravity took the starboard wing over.
Physics took over. Plane flipped and rolled upon loss of port wing, smearing a rolling fireball of the remaining fuel load from the starboard wing for another half a mile.
Louisville is now a firestorm as a result.
Respect to the flight crew; rest in peace, they made the best they could out of a really shitty scenario. They flew it all the way down.
Footage:
https://x.com/osinttechnical/status/1985845987684855969?s=46
https://x.com/faytuksnetwork/status/1985849267152699741?s=46
https://x.com/faytuksnetwork/status/1985848132500885995?s=46
https://x.com/faytuksnetwork/status/1985843126934614297?s=46
Standard procedure at V1 is commit to the takeoff and diagnose the problem in-air. Much of your comment is pure speculation until flight data recorders come back, we have no idea what the crew was thinking or what issues they were even aware of.
You're 100% right, and that's exactly what I'm getting at - they hit V1 and were aware they had a serious problem, but couldn't abort.
As far as the rest of my comment - watch the videos that I linked.
> they tried to take off instead of accelerate past the runway at ground level
Do runways have some sort of barrier between them and the next "important" thing. It seems like that would be prudent both for cases like this, and breaking failures following landings.
> Do runways have some sort of barrier between them and the next "important" thing. It seems like that would be prudent both for cases like this
Ha, Jeju Air Flight 2216 smashed into a barrier on the second landing attempt in Muan last year [0], and people commented "How could there be a barrier at the end of the runway, so obviously stupid, irresponsible", etc.
Now a plane does not smash into a barrier at the end of the runway and people suggest putting barriers at the end of the runway.
Don't mean to attack parent post, but may I suggest that
a) hordes of experts have thought long and hard about these issues, and it is unlikely that you can encounter this for the first time as a lay person and come up with a solution that has eluded the best engineers for decades ("why don't they attach a parachute to the plane?"), and
b) we are very close to an optimum in commercial aviation, and there are few if any unambiguous ("Pareto") improvements, but rather just tradeoffs. For example: You leave cockpit doors open, terrorists come in and commandeer the plane to turn it into a weapon. You lock the cockpit doors closed, and suicidal pilots lock out the rest of the crew and commandeer the plane to turn it into a weapon of mass-murder-suicide.
There are no easy answers.
[0] https://en.wikipedia.org/wiki/Jeju_Air_Flight_2216
ETA: In 2007 an A320 overran a runway in Brazil and crashed into a gas station, killing 187 pax & crew + 12 on the ground. https://en.wikipedia.org/wiki/TAM_Airlines_Flight_3054
One improvement is a bed of concrete at the end of the runway that will catch the wheels and slow an airplane down to a stop. Pretty much everyone agrees it’s a good idea but it’s not always possible due to space needs or cost. https://en.wikipedia.org/wiki/Engineered_materials_arrestor_...
Or a ramp with "one-way teeth" that stops it with gravity and stops it from sliding back down with teeth.
The ramp will need to be very long and very high in order to absorb the momentum of a fully loaded widebody jet. Not something that you'd want near a runway where planes can land in either direction.
> Do runways have some sort of barrier between them and the next "important" thing.
Some do. Here is what it looks like when an overshooting plane utilizes such a barrier: https://www.youtube.com/watch?v=zW71FrX8t_g
179 dead.
Consider the possibility that gigantic flying aluminum tubes filled with tons of flammable fuel hurtling around at hundreds of kilometers per hour comprise a dilemma that has no trivial answers. Even defining what "important thing" means at any given instant is not straightforward.
Unless you have a berm several dozen meters high with a 100 meter base, you ain't stopping something like this from a physics standpoint unfortunately.
Many airports have this problem. The recent korean air disaster which echos this is another example. BTW, this is why most airports, if possible, point out to sea...
Newer airports usually try to have space, that's the only thing helping with the physics involved here.
Older airports might have EMAS [1] retrofitted at the ends to help stop planes, but that's designed more for a landing plane not stopping quickly enough (like [2]) - not a plane trying to get airborne as in this case.
[1] https://en.wikipedia.org/wiki/Engineered_materials_arrestor_... [2] https://en.wikipedia.org/wiki/Southwest_Airlines_Flight_1248
There is a dead zone between rejection and successful take-off speeds. We see it hit too often.
I think pilot training is playing a factor. A normal rotation kills too much energy. One engine can climb when you have some airspeed and get clean, but if you lose too much energy on rotation, the inefficiency of the AoA for the rest of the short flight means that engine can no longer buy you any up. I've seen too many single-engine planes going down while trying to pitch up the whole way down.
So, less aggressive single-engine rotations and energy absorbers at the ends of runways that can't get longer. This seems like the kind of thing where we do it because it removes a significant cause of people dying.
Just watched this angle a few more times: https://x.com/BNONews/status/1985845907191889930
Another crash video shows the aircraft clearly descending before colliding with anything. It manages to go up a bit, so it's fast enough to get airborne. The normal looking rotation kills too much energy. The plane is then too inefficient to maintain speed. AoA goes up while energy goes down. Power available goes negative and then it's over.
Rotation does increase drag, but you need to rotate in order to achieve the necessary angle of attack. The only way to reduce the rotation angle is by going faster than the normal rotation speed for the given weight and airfield density altitude, but doing so is out of the question in this scenario.
> It manages to go up a bit, so it's fast enough to get airborne. The normal looking rotation kills too much energy.
Yes, it did get airborne for a few seconds but from the video below, it looks like the left wing was damaged by the fire and could not provide enough lift, then the right wing rolled the plane to the left causing the crash.
https://bsky.app/profile/shipwreck75.bsky.social/post/3m4tvh...
> looks like the left wing was damaged by the fire
The wings and aerodynamics don't really care if air or air with combustion are flowing around them.
Roll is a consequence of the loss of control due to low speed and the yaw of the good engines. Speed up, rudder works, plane might maintain positive climb.
> The wings and aerodynamics don't really care if air or air with combustion are flowing around them.
Not saying it's what happened here, but if the heat is intense enough to deform the wing / control surfaces, it matters.
For skin, a few seconds might be significant. For the spars, not nearly enough time to matter. It's also not at cruise speed slamming into a downdraft or anything. This is about a 1G loading. Negligible for a while. While the fire looks cool, there's a lot of free stream mixing in and the temps won't really get that high beyond the cowling.
Some runways have been extended with ‘engineered materials’ surfaces, often a form of porous concrete into which an airliner’s wheels will sink, absorbing a lot of energy and arresting the airplane without causing it to break up. It is very effective for landing overruns, but I don’t know about last-seconds aborted takeoffs.
Security/debris fencing yes, but that's like, orders of magnitude short of what would stop the amount of energy we're talking about here.
You also don't particularly want it to be catastrophically effective as there are real world cases where planes have clipped the fence and then NOT gone on to crash, or at least to crash in a fairly controlled manner with the majority onboard surviving. Hitting a brick wall at 180mph is going to have a 0% survival rate.
Yet a reinforced concrete wall of e.g. triangular section and anchored with "long enough" piles would be about the only not-that-expensive way to turn a short strip of "airport land" past the EMAS into a V1 stopping supermarket.
Sorry for ignorance but why is the right thing to continue to take off with an engine on fire?
It depends on whether or not, at the point in which you realize you have an engine on fire, you have room on the runway left to stop.
As I understand it, there is a low speed regime, under 80 knots, where are you stop for basically anything.
Then there is a high speed regime, where you only stop for serious issues, because you now have so much kinetic energy that stopping the plane, while still possible, will involve risk. (i.e. fire from overheated brakes.)
At a certain point, called V1, there’s no longer enough room to stop, no matter what your problem is. You’re either getting airborne or you’re crashing into whatever is ant the end of the runway. In general, getting airborne is the safer option, while obviously still not risk free.
However, this calculation also assumes that the engine fails in an isolated fashion, and its failure did not affect the other engines. If the failure of the left engine threw off debris that damaged the middle engine then we are now talking about a double engine failure. I’m sure the pilots knew there was a problem with the engine when they made the decision to continue, but it’s possible that problems with the middle engine weren’t apparent yet and that it only started to fail once they were committed.
Obviously, this is just speculation, and we will have to wait for the preliminary report at least.
RIP
Being untrained but spending a little bit of time in a full motion 737 simulator that’s used to train and certify commercial pilots, I was amazed at how quickly things happen even in a scenario with no faults.
This situation (single engine failure at V1) is something that commercial pilots are certified in at every recurrent certification since it’s one of the most difficult you can be in. The crew now need to climb and go around for a landing on one engine while simultaneously running through the engine failure (and also likely fire) checklist. I don’t know if a double engine failure at V1 on a fully loaded 3 engine aircraft is technically survivable or if it’s something that’s trained on. They were put in an incredibly difficult situation just based on what reports we’ve already seen.
It was at a point where they were going to fast to stop or land safely. At that point you're just trying to pick the best place to crash.
^What Atrus said
V1 is the speed at which you can still stop the plane before the end of the runway. (It is computed for each takeoff based on runway length, aircraft mass, takeoff engine power setting, flaps, wind, runway condition, etc.)
When the plane reaches V1, pilots take the hand off the throttle: they're committed to takeoff, even if an engine fails. It is better to take off and fix the problem or land again, than to smash into whatever is beyond the end of the runway.
Isn't there any margin? Does it calculate stopping before end of runway or before causing damage?
Surely uncertainty about the situation contributes to defaulting to committing, but what if it's a passenger plane and at V1 pilots know they've lost power? Wouldn't veering into highway at 30 mph be weighted against certain, big loss of life?
Edit: I now see that this has been partially answered by uncle comment
A fully loaded plane is extremely likely to turn into a fireball if it hits anything on the ground, even at 30mph. It's just a thin shell of aluminum with tons of fuel sloshing inside.
To avoid mass casualties at the end of the runway - on the road, or the buildings that the runway points to. Check the layout on google maps.
More specifically, V1 is the max speed at which you're about to take off, but you can still abort from. They hit that max speed and realized there was a major problem that hypothetically, they could have slowed down from, but realistically was not possible. They had no choice.
Video of the crash, left (?) engine was already engulfed in flames while taking off
https://x.com/BNONews/status/1985845907191889930
https://xcancel.com/BNONews/status/1985845907191889930
Edit: just the mp4 https://video.twimg.com/ext_tw_video/1985845862409334784/pu/...
There is an incredible amount of ground damage! Just wow, this is very bad https://files.catbox.moe/3303ob.jpg
The damage on the ground is scary to look at. I think the only silver lining here is that it was "just" a sparser industrial area and there weren't any homes. I'm really curious about what the investigation will reveal in a few months. This doesn't look like a "regular" engine fire from a bird strike or so, you would normally expect the flames to come out the back and not over the wing. And at least in theory the MD-11 should be flyable with just two engines, although flames on a wing is probably "really really bad" just by itself already. Too early to speculate about what happened though.
> And at least in theory the MD-11 should be flyable with just two engines
Flying with two engines and taking off without an engine in a loaded aircraft are two very different things. A lot more thrust is needed during takeoff than after.
Taking off with one engine inoperative (on a multi-engine aircraft, obviously - you aren't going to get anywhere with your only engine gone) is completely normal/within design parameters, albeit undesirable.
In fact, it being normal almost certainly contributed to the scale of this accident, since a single engine failure during the takeoff roll isn't considered enough of an emergency to reject the takeoff at high speed (past a certain speed, you only abort if the aircraft is literally unflyable - for everything else, you take the aircraft & emergency into the air and figure it out there). The crew wouldn't have had any way to know that one of their engines had not simply failed, but was straight-up gone with their wing on fire to boot.
> The crew wouldn't have had any way to know that one of their engines had not simply failed, but was straight-up gone with their wing on fire to boot.
I don't know about the MD-11 itself, but other aircraft from that time period have sensors to detect and report overheat and fire in various parts of the aircraft, including engines and wings.
Well, there's a very big difference between "Engine fire: some of the combustion chamber's heat and flame has breached containment" and, say, "Engine fire: the engine has exploded, catastrophically damaging your wing which is now visibly on fire". However, both things are reported in the cockpit as ENG FIRE.
There's also a very big difference between "Engine failure: something has damaged or jammed enough components that the turbines are no longer spinning fast enough to produce thrust or drive the generators" and "Engine failure: the engine is no longer attached to the aircraft, which is why it is no longer producing thrust". However, both things are reported in the cockpit as ENG FAIL.
(Un)fortunately, cockpit warnings prioritise the what (so to speak) and not the how or why. On one hand, this makes decision-making a lot simpler for the crew, but on the other...well, in rare cases the lack of insight can exacerbate a disaster. Depending on when exactly the engine gave out, this poor crew might have been doomed either way, but they might have been able to minimise collateral damage if they knew just how badly crippled the aircraft was. And there was a very similar accident to this one (actually involving the predecessor of the MD-11, the DC-10), American Airlines 191 - one of the engines detached from the aircraft, damaging the leading edge of its wing in the process, causing that wing to stall when the crew slowed down below the stall speed of the damaged wing in a bid to climb. If they could have somehow known about the damage, the accident might have been avoided entirely as the crew might have known to keep their speed up.
I’m sure they knew there was an issue, but I don’t think the sensors can differentiate between “your engine is on fire, but if you can shut it down quickly, everything will be cool.” and “half your entire wing is on fire and your engine is pouring flame out the front/top instead of the back”
This puts an impractical amount of faith in the sensor wiring when the whole pylon and cowling are shredded.
I don't know what the MD-11 would have had, again I didn't work on it. But the systems used for other aircraft would have reported an alarm based on what I saw in the video, at least they were designed to do that. The LRU receiving the sensor inputs wouldn't typically be in the wing and would be able to continue reporting the alarm condition even if the sensors fail. In fact, the lack of current from the sensor (for the systems I worked on) would have been enough to trigger the alarm if the sensor were completely eliminated.
No reading is not quite the same as "hot", but I'm sure it did contribute to discerning simple compressor stall to whatever this was.
Every multi-engine airliner is designed to be able to take off safely even if an engine fails at a critical moment. What might have happened in this case is that the mechanism of failure of one engine caused damaged or interfered with the operation of another engine (via smoke, debris, etc.), and taking off with two engines degraded is not part of the design criteria.
I specifically remember watching a flight test doing an aggressive takeoff and having the voiceover say that aircraft (two engine) need to have enough power to take off full with one engine. And so can take off very steeply empty with two engines. Would that not also be the case for these planes?
Yes, planes are designed to be able to take off with a lost engine. Usually this will extend the roll a bit because the speeds are different for engine out operations. This isn't the first MD-11 with an engine out take off, 5 years ago a FedEx MD-11 took off with a failure in the left engine[1]. Slightly different case, obviously, but it's certainly something that is accounted for when designing planes.
[1] https://www.avherald.com/h?article=4dfd50b9&opt=0%20
That being said, depending on how you lose the engine it can really mess up the takeoff; AA191 was lost when an engine detached from the plane on takeoff and took out part of the wing and hydraulic system with it. https://en.wikipedia.org/wiki/American_Airlines_Flight_191
> when an engine detached from the plane on takeoff...
https://imgur.com/a/NYlrLYO
https://cdn.discordapp.com/attachments/757091156717862935/14...
Source: https://reddit.com/r/flying/comments/1ooms7t/ksdf_accident/n...
All planes are definitely capable of taking off safely even if they lose an engine at the worst time. Whatever happened here, I would be shocked if lack of thrust in the 2 remaining engines was a significant factor unless someone really screwed up the load calculations and they were overweight for conditions.
Lack of thrust in the "taken out by debris" sense seems to be the case here.
Looks like a compressor stall on number two engine two seconds into the video.
I don’t know, that looks like a lot more than just a stall. There was a ton of flame that looked like it was coming out of the front or top of the engine, rather than just something shooting out the back.
I think you're looking at the left wing (number 1) engine; GP is talking about either the tail or right wing engine. (I think tail is number 2 on MD-11.) There's a brief explosion visible through the smoke at about 1-2 seconds in, to the right of the engine visibly on fire; that's probably what he's talking about.
Freeze frame: https://imgur.com/a/c3h8Qd3
And having 2 out of 3 engines fail (or underperform) would explain the insufficient climb thrust.
Right!
Yup makes sense. Now seeing photos of the entire left engine on the ground by the runway and the implication that however it failed it might have damaged the tail engine.
I would say it does not, in fact, look like a compressor stall. It looks very much like an uncontained disassembly, presumably from fan blades that suffered a catastrophic failure and broke up in a way that exceeded the limits of the engine's containment.
Obviously impossible to tell from some cell phone type videos. Being struck by something is also possible. But it sure does look like an uncontained engine failure.
I think you're looking at engine number 1, while GP is talking about engine 2.
https://news.ycombinator.com/item?id=45818448
The second video here shows an incredibly close view of the impact from a nearby dashcam.
https://www.wdrb.com/news/ups-plane-catches-fire-and-explode...
> There is an incredible amount of ground damage!
It's fortunate it wasn't taking off the other direction, towards the adjacent downtown of Louisville (https://www.google.com/maps/place/Louisville+International+A...)
That is an incredible video.
UPS2976
https://www.flightaware.com/live/flight/UPS2976
This is probably the worst way a plane could go down. Maximum effect in term of damage. Cargo plane apparently reached V1 (go/no go speed) on the runway, and suffered a catastrophic engine failure. They passed V1, so they knew they were going down. Engine was shedding large debris, including the housing (!!!) which is a shrapnel shield.
They were on fire just as they reached V1.
Plane was fully loaded with 38,000 LB of fuel for 12 hour flight to hawaii. Worst case scenario.
Pilots did the heroic thing - they tried to take off instead of accelerate past the runway at ground level at 160 MPH to minimize collateral damage (highway and warehouses at the end of the runway) and crash and die somewhere else.
Instead, they clipped the UPS factory because they were so low, they tried to clear it but did not. Plane then hit the ground port wing down, shearing it off entirely, smearing a fireball of jet fuel across half a mile (not an exaggeration) before the plane flipped. Crew were likely dead by then, footage shows the cockpit being slammed into the ground by the flip once the port wing was gone and gravity took the starboard wing over.
Plane flipped, continued to smear half of the fuel load for another half a mile.
Louisville is now a firestorm as a result.
Footage:
https://x.com/osinttechnical/status/1985845987684855969?s=46
https://x.com/faytuksnetwork/status/1985849267152699741?s=46
https://x.com/faytuksnetwork/status/1985848132500885995?s=46
https://x.com/faytuksnetwork/status/1985843126934614297?s=46
> They passed V1, so they knew they were going down.
To know this, they would have to know they had lost multiple engines. Clearly this is the case by the end, but it's not clear who realized what at what time.
The NTSB investigation will bring more light.
Agreed, only the NTSB investigation will provide a full account. But if you look at where they were on the runway, they had passed V1.
Yes, but multiengine aircraft are designed to take off with one lost engine.
[Off-topic] >The police department also urged those in the area to turn off any air intake systems as soon as possible due to the smoke in the area.
Excellent edge-case for IFTTT thermostat. Localized air quality alert --> Intake offline.
Side view https://x.com/TexasHodlerMom/status/1985870817133985970
Another DC-10/MD-11 crash. Does UPS perform their own engine maintenance, or do they outsource the work? What is the effect of the recent layoff of 40,000 and the current cost-cutting project?
Maybe wait with the judgements until the report is in? There are so many possible reasons why this could have happened that have nothing to do with the two items you listed (though it maybe that it does, it is just a bit pointless to assign blame before you know what the cause of the accident was).
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Zero. This almost certainly has nothing to do with the shutdown.
There's just no way that's actually true though in a complex environment like airports and airplanes.
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This is a silly take because having your ATC workers unpaid for over 30 days is going to increase the risk of catastrophic plane crashes. Even if this had nothing to do with this.
Footage of plane crashes are certainly important to know _this could start happening to passenger planes_
It is also true that the risk of plane crashes goes up when you swap prioritization of ATC workers who attended ATC school for prioritization of those who said they were bad at science on a questionnaire. Nevertheless, it's highly unlikely that you could identify that as a primary cause of any individual crash.
*"something like this", perhaps. Rather than this specifically.
Likely no impact. It was departing with ~75 tonnes of fuel and suffered an unrecoverable mechanical failure.
https://www.flightradar24.com/blog/flight-tracking-news/majo...
> suffered an unrecoverable mechanical failure
But was un-discoverable? Or un-preventable? Seems plane inspectors and safety-related roles were affected and have been furloughed:
> But for the people involved in inspecting our planes to ensure they follow Federal Aviation Administration safety standards, the situation is more complicated. While principal aviation inspectors were told to keep working, assistant-level inspectors and other support staff were sent home and then had to be recalled.
https://archive.ph/rEpTx
Of course it was not unpreventable, though it might turn out that preventing it would have been unreasonably expensive.
But, the FAA inspectors are not responsible for making sure planes are safe to fly. They are responsible for making sure the people whose job that actually is, are doing their jobs effectively. That’s a critical difference.
It’s UPS maintenance personnel who are responsible for making sure that UPS planes are safe to fly. Yes, it’s possible that there is some institutional failure at UPS, that could have been caught if FAA inspectors were working in the past 30 days, but this isn’t the most likely scenario, and the root cause and responsibility (in this hypothetical) would still lie with UPS and not the FAA and the shutdown.
Aviation regulations are updated in FAFO basis("written in blood" is the more common version).
Thats kind of insincere given how much safer flying is compared to driving a car. Modern flight is not dangerous, its just more spectacular when failures happen.
À lot of the reason why flying is so safe now is because of the culture of investigating every incident to make sure they won't happen again.
And, unfortunately, it's not that rare that the investigations to turn up things that were the result of corners being cut. I'm guessing that's what the "FAFO" comment points to.
Flying is only safer than driving a car when extremely regular and frequent maintenance is performed and performed correctly. The safety of flying goes down very fast when the maintenance effectiveness goes down. That is not true for cars.
Probably also worth pointing out that flying is only safer for Part 121 operators (airlines) -- private jets, sightseeing helicopters, skydiving operators, and general aviation are all more dangerous.
The maintenance and inspection tends to be done by MROs, and any institutional issue within UPS's MRO would have been identified before the shutdown by the FAA and other regulators.
But based on your comment history, you aren't from the US, have not ever visited America, do not care to visit America, and haven't interacted with Americans, so I doubt you have on the ground experience with the US. But that also leads to the question of why you even care to comment on our affairs if you dislike us to such a degree.
Asking people not to engage in political discussion after lighting the fuse here is a bit rich.
You already know the answer. You answered yourself. Yet you ask this and then saying "don't start a flame war" is pretty disingenuous.
"I'm just asking questions."