UPS plane crashes near Louisville airport

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.

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?

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 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.

Could they have not hit V1 but decided to take off anyway to minimise damage (i am guessing the reverse thrust might be impossible to stop?)

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 solution is to "free" the perimeter of takeoff/landing. Bonus: People don't have to chose to work/live in these noisy areas. I understand some areas have challenges to come up with space but the US has tons of space and maybe the sea should be used to host these airports.

Or a ramp with "one-way teeth" that stops it with gravity and stops it from sliding back down with teeth.

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.

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.

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.

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

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Yes, but multiengine aircraft are designed to take off with one lost engine.

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_

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).

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.