> 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?

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HPsquared a day ago | parent | next [-]

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.

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bombcar a day ago | parent [-]

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).

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Modified3019 a day ago | parent | next [-]

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.

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		[deleted]

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beerandt 19 hours ago | parent | prev [-]

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.

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mvkel 20 hours ago | parent | prev | next [-]

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

and

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

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tzs 11 hours ago | parent | prev | next [-]

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.

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potato3732842 a day ago | parent | prev | next [-]

>What is the difference?

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

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singleshot_ 21 hours ago | parent | prev [-]

Hydraulic pressure