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[LC0112G]

Sorry - that first sentence should have been....

"#3 is the tail engine? Anything departing #1 with enough energy to penetrate the fuselage is going to miss the tail engine."

Point is, I can't find any instances of an engine on one wing causing damage to an engine on t'other wing. Yes there have been instances (on both B-707's and B-747's) where one engine has failed and knocked the other one on the same wing off, but never on the opposite wing.

[Kevin Wood]

No.3 would be the engine on the starboard wing. They are counted from port to starboard.

I think the cowling of the departed no.1 engine ended up the other side of the runway so quite possible it killed no.3.

However, one of the videos shows no. 2 at the back spitting out sparks just after rotation. It quite possibly ingested fire from the burning port wing at that point.

[TheBoy]

Yes, to clarify, it is the starboard engine I'm talking about the rumours of it flaming out as the nose lifts. Which as Kevin Wood says, is called No3.

Additionally, there is also talk of there being a direct line of sight between the No1 and No3, under the fuselage, so maybe it didn't penetrate the fuselage.

As a cargo plane, my thoughts were how likely would it be for engine debris, admittedly at high speed with a lot of spin, to penetrate the fuselage (easy, thin aluminium) and the cargo (less likely?)

[LC0112G]

As a cargo plane, my thoughts were how likely would it be for engine debris, admittedly at high speed with a lot of spin, to penetrate the fuselage (easy, thin aluminium) and the cargo (less likely?)

There is no real difference between a cargo and a passenger planes construction. Some cargo planes do have a strengthened floor to take the weight of pallets and extra loading doors, but the wings, skins and bulkheads are the same. I don't think the cargo has any bearing on this, because for parts of an engine to hit the cargo they have to travel up, so they will miss the other engine if they emerge out the other side of the fuselage.

AIUI there are contained and uncontained engine failures. Smaller things like individual engine blades are supposed to be contained within the engine cowling if they break off. The engine will be destroyed, but things shouldn't fly out of the sides. This is tested during engine certification, and is often implemented by having kevlar bands around the engine. Larger parts - like rotor disks (either whole or segments) are considered to have infinite energy and cannot be contained. If they do break off, they will go through virtually anything. The safety mitigation for these is simply to route critical wiring and hydraulics out of being in direct line with the high energy rotating parts. Engines are also mounted forwards of the front wing spar, so if anything does fly off it doesn't puncture fuel tanks.

If some high energy part of #1 did escape and somehow hit #3 it will be the first known incident of this happening. It will have very serious consequences for air travel. Aircraft are certified to be able to takeoff, fly and land on n-1 engines on the basis that it's highly unlikely that two engines can be damaged by the same event. If that assumption proves to be false then it opens a huge can of worms. n-2 isn't possible on any aircraft, and since almost all are now twins (B-737,767,777,787,A-319,320,330,350) n-1 means zero.

[TheBoy]

As a cargo plane, my thoughts were how likely would it be for engine debris, admittedly at high speed with a lot of spin, to penetrate the fuselage (easy, thin aluminium) and the cargo (less likely?)

There is no real difference between a cargo and a passenger planes construction.

Yes, the bit I was wondering is if debris would penetrate the cargo easier than it would penetrate the organic matter in a passenger jet....