[filleduchaos]

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.

[ragazzina]

> 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.

What is the difference?

[HPsquared]

Wider effects like damage to the wing or changes to aerodynamics.

Edit: and damage to other engines, possibly engine #2 in the tail ingesting debris in this instance.

[bombcar]

That's the biggest, the weight gone entirely unbalances the plane; if you knew exactly what happened you MIGHT be able to keep it level (and it seems they did for a bit) but eventually airspeed drops, it tips, and cartwheels (which is apparently what it did from the videos).

[Modified3019]

The aircraft hit the roof of a UPS warehouse, barely clearing it before coming down in the parking lot/junkyard nearby. So when we see it turning over in its last seconds (like the trucker dash cam video), it only had one wing at that point.

[beerandt]

Deadweight or no-weight engine is a relatively negligible problem in terms of the weight-balance envelope.

Cut fuel & hydraulic lines near that engine (that affect the other engines/ apus) (or less likely structural or aerodynamic problems) is what's going to shift this from "engine failure" recoverable problem to a global nonrecoverable one.

[mvkel]

It's the difference between "I can't walk because my leg fell asleep"

and

"I can't walk because I have no legs"

[tzs]

A good example of the difference it can make was the Flight 191 crash in Chicago in in 1979, which had an engine come off on takeoff: https://en.wikipedia.org/wiki/American_Airlines_Flight_191

The engine coming completely off tore through hydraulic lines, which were need to keep the slats extended. Airflow forced the slats to retract.

Here's what then happened:

> As the aircraft had reached V1, the crew was committed to takeoff, so they followed standard procedures for an engine-out situation. This procedure is to climb at the takeoff safety airspeed (V2) and attitude (angle), as directed by the flight director. The partial electrical power failure, produced by the separation of the left engine, meant that neither the stall warning nor the slat retraction indicator was operative. Therefore, the crew did not know that the slats on the left wing were retracting. This retraction significantly raised the stall speed of the left wing. Thus, flying at the takeoff safety airspeed caused the left wing to stall while the right wing was still producing lift, so the aircraft banked sharply and uncontrollably to the left. Simulator recreations after the accident determined that "had the pilot maintained excess airspeed the accident may not have occurred.

[potato3732842]

>What is the difference?

Wanting to be in the air vs wanting to over-run the end of the runway.

[singleshot_]

Hydraulic pressure

[eternityforest]

Could they add cameras to solve this issue?

[roryirvine]

During engine failure / fire situations, I would expect that pilots are likely to be too busy to have any time left over for peering at a video feed, trying to assess the state of the wing.

In emergencies, information overload tends to make things worse, not better.

[ExoticPearTree]

Having cameras pointed at the engines/wings like rearview mirrors would be helpful. It does not add that much workload if you take a quick glance in the “mirror” and figure out what the problem exactly is.

And now we have technology that allows for cameras everywhere to give a better situational awareness across all critical aircraft surfaces and systems.

It is going to take a little bit of adjusting to, but it will help improve safety in a tremendous way.

[cedilla]

This would need to be tested. There's a lot going on already during normal take-offs. Now you're in a situation where the engine fire alarm is going off, probably a few other alarms, you got so many messages on your display that it only shows the most urgent one, you're taking quick glances at 50 points in the cockpit already.

And how would the cameras even work? Are the pilots supposed to switch between multiple camera feeds, or do we install dozens of screens? And then what, they see lots of black smoke on one camera, does that really tell them that much more than the ENG FIRE alert blaring in the background?

Maybe this could help during stable flight, but in this situation, when the pilots were likely already overloaded and probably had only a few seconds to escape this situation - if it was possible at all - I can't imagine it being helpful.

[ExoticPearTree]

You know how the tail camera works on the new planes? Something like that, which can be far away from the wings, but get the full picture. Am I saying it's the solution for everything? No. But after you go through the memory committed items during an emergency, you can take a look outside and be like "ah, I see better what the problem is".

If we don't try to see how it goes, we won't know if it is a good idea or not.

[wongarsu]

It'd certainly need more thought put into it than just showing the camera view from the entertainment system. Either just one camera on the tail pointed forwards, so you have one single camera that can show the whole plane, or two cameras in the front, one pointed at each wing. Two cameras is worse than one, but they are less likely to be affected by smoke or blood splatters or whatever. Maybe give each pilot one of the camera feeds. And you'd have to fit a dedicated screen for the video feed so pilots don't need to switch through screens in an emergency.

It'd take lots of testing and engineering. But especially in cases where you have multiple warnings going off I imagine that a quick view at an exterior camera can often give you a clearer/faster indication of the situation

[HeyLaughingBoy]

How does that work in the dark/rain/snow? Or are we now going to add lights pointing in the direction where the camera is facing. And then what do we do about the fact that aircraft external lighting has to follow regulations?

[krisoft]

> Having cameras pointed at the engines/wings like rearview mirrors would be helpful.

Helpful in what way? What are the pilots going to do with the information?

[ExoticPearTree]

They won't have to rely on cabin crew description of what they see over the wings or have to send one of the pilots to take a look (see UA1175).

[sim7c00]

its super weird to me this isn't a thing, and there's resistence to the idea. I mean, if they are already masters at glacing at 100000 differnent indicators and warning messages etc. and processing them at super speeds (they really do!) then i'd say a monitor with a bunch of buttons below it to switch feeds (maybe a little more elaborate, but not tooo...) would be helpful.

the problem might be getting trained and experienced pilots to adjust to it since they are already in a certain flow of habits and skills to apply in their job, but new pilots surely could learn it as they aren't so set on their ways yet and have the opportunity to build this new data into their skillset / habits.

[krisoft]

Okay. So you mean in general it would help in some cases. Not that in this case it would have helped.

> see UA1175

I'm familiar with the case you are mentioning. I'm also aware that they sent a jump seater to look at the engine. But did seeing the engine provide them with any actionable information? Did they fly the airplane differently than if they would have just seen the indications available in the cockpit?

[lazide]

Sure, but in this situation there is zero time for any of that.

[zuppy]

They surely can and this has been done. On one the flights that I took with Turkish Airlines they had a few video streams from different sides of the airplane. One was from the top of the tail and you could see the entire plane.

Now... not sure how much that is helpful in this kind of emergency, they really didn't have time to do much.

[fredoralive]

I'm not sure they usually have the views on screen in the cockpit in flight, even if available (and an old MD-11 freighter won't have the cameras in the first place). The picture of an A380 cockpit (on the ground) on Wikipedia does show the tail view on a screen, but its on the screen normally used for main instruments. With an A380 that had an uncontained engine failure causing various bits of havok (Qantas 32?) IIRC the passengers could see a fuel leak on the in flight entertainment screens, but they had to tell the crew as AFAIK they didn't have access to the view in the cockpit in flight.