SW Airlines catastrophic in-flight engine failure

The pilot is being praised for her nerves of steel in handling the crisis and bringing the plane in safely. TV Movie on it's way.
 
William Parcher said:
There's a fun physics puzzle for the forum.

When an engine explodes on a jet plane, do all of the shrapnel pieces go flying at speeds slower than the plane itself? Could any piece actually fly forwards and hit the cockpit area?
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If the engine actually exploded, then parts could go flying in any direction, relative to the plane.

However, that's apparently not what happened here. If the engine or parts thereof merely comes apart instead, then it's the components' rotary motion just before coming apart that matters most; that motion will be along a planar geometrical surface (can't just say "plane" there without confusion...) perpendicular to the engine's axis of rotation and perpendicular to the fuselage of the plane. So in theory, most of the resulting impacts would be in the middle of the fuselage closest to the engines, from the parts thrown "sideways"...

Except that once pieces come off of the engine, they're exposed to a 500 mph headwind relative to the aircraft. Smaller pieces, especially, are going to be blown tail-ward by that wind very quickly. That makes a part being thrown forward, massive enough and fast enough against the headwind to impact the cockpit area, very unlikely. I don't suppose it's completely impossible, though.

If only one significant piece (the fan blade) came off, then it's just bad luck for it to have hit the fuselage; even worse to have hit near a passenger's head or torso. It could have started off going any direction in its circle, including straight up, straight down, or horizontally directly away from the fuselage. On the other hand, it didn't hit any other vital part of the flight systems.
 
William Parcher said:
There's a fun physics puzzle for the forum.

When an engine explodes on a jet plane, do all of the shrapnel pieces go flying at speeds slower than the plane itself? Could any piece actually fly forwards and hit the cockpit area?
Click to expand...

They would initially have the same forward speed as the plane, but wind resistance would slow them down, how quickly depending on the mass and shape of the objects.

ETA: Myriad's post explains it well.
 
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The engine cowling or shroud was found 70 miles from where the plane landed.

So that one blade tore off the shroud and also punched out that window? Did the one blade break into pieces and so there were numerous high speed projectiles?
 
William Parcher said:
I think I read a CNN article this morning saying that there was fuselage damage in addition
to the window blowout.
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I've seen a photo showing a decent puncture wound in the middle of the lettering on the side of the plane. No idea where I saw it.
 
William Parcher said:
The engine cowling or shroud was found 70 miles from where the plane landed.

So that one blade tore off the shroud and also punched out that window? Did the one blade break into pieces and so there were numerous high speed projectiles?
Click to expand...

If I had to guess, I'd say the shroud went outboard and did all the damage to the wing leading edge, and did not come inboard and strike the fuselage.

I would guess that a part from the rear front end of the engine struck the window.
 
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asymmetry in thrust and drag

Link

I am not a pilot, but reading this article I get the impression that her flying skills were impressive.
 
Delphic Oracle said:
Given the fuselage damage appears to be well aft, that certainly lessens the potential for uncontained failure being the cause.

As for pressure pulling someone out of the plane, a pilot once barely survived a windshield failure and was barely held in the plane by his ankles.

This is where the tapatalk signature that annoys people used to be
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You forgot about drag...
The fan failure pattern by FAA decree is +/-15 degrees for Fan, Stage 1 and stage 2 compressor blade, +/- 5 for large turbine fragments, +/- 15 degrees for small turbine fragments
 
William Parcher said:
There's a fun physics puzzle for the forum.

When an engine explodes on a jet plane, do all of the shrapnel pieces go flying at speeds slower than the plane itself? Could any piece actually fly forwards and hit the cockpit area?
Click to expand...

Yep. They are airfoils, after all. Little propellers, if you will. Most dangerous place to stand on an engine run-up is forward and to the side.
 
LTC8K6 said:
https://pbs.twimg.com/media/DbBrG9_XUAYBEOh.jpg

Circles around apparent damage. (Not sure who made the circles)

The window frame looks a bit distorted.
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The fuselage is very glossy and reflective. The circles on it might be showing reflections rather than damage.

The frame does look distorted but then that might be some of that wispy fabric or insulation peeking out and giving the appearance of an irregular line. Check out the interior photo of that broken window.
 
Delphic Oracle said:
Normal air handling systems on planes often have power supplied by engines. If the normal air handling system shuts down above a certain altitude, the masks deploy.

This is where the tapatalk signature that annoys people used to be
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LTC8K6 said:
I would think the whole air handling system would be fine on one engine, though.
The APU can also supply bleed air for pressurization, I believe.

Of course, the system itself could have been damaged by pieces of the engine.

Or, the pilot could simply have decided to deploy the masks from indications on her instruments.
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Although the remaining engine was capable of powering the system, passengers reported a smell of smoke and "ash coming from the vents", so the ventilation system was at least compromised and contaminated if not disabled completely. Maybe safety system was able to detect that condition and deploy the masks.

I'm actually not sure if the pilot is able to deploy the masks manually, or why the automated system would not have deployed them once it detected the same readings that would have prompted the pilot to do so in this case.

Passengers have said that the window "blew out" around ten seconds after the engine "exploded". Possible scenario: the debris broke the window immediately after the engine failed, but the window didn't blow out completely right away. It only cracked enough to allow a small cabin pressure leak, which was detected by the safety system (which deployed the oxygen masks). A few seconds later, building wind and pressure stress finally pulled the broken window apart.
 
Checkmite said:
A few seconds later, building wind and pressure stress finally pulled the broken window apart.
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If that is what happened then the woman was not hit by flying shrapnel and no part entered the plane through the window. That could be true.

As an aside, I like the window seat and have noticed that there appears to be two thick panes with an air gap between them. Then also a thinner clear plastic pane right where your face is (then also a pull-down shade).
 
William Parcher said:
The window frame is not bent or smashed. It seems like only the panes were broken out.

Also notice that this window is directly above the rear portion of the wing. Some photos give the illusion that it is behind the wing.

Good photos here including the lost cowling: http://www.dailymail.co.uk/news/art...light-tells-tried-save-mother-sucked-out.html
Click to expand...

Incidentally one of those picture captions says the lost fan blade was also recovered from where it had fallen. I hadn't heard that until now.
 
Bird strike to the cowling, cowling into the fan, air stream did the rest of the damage. ???
 
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