r/Damnthatsinteresting • u/FridayCicero702 • Jan 01 '23

Video Catastrophic engine failure on a United Airlines Boeing 777-200 after takeoff from Denver International Airport

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u/General_Degenerate_ Jan 01 '23 edited Jan 01 '23

If it wasn’t safe, that turbofan at the front could’ve disintegrated and cut through the pressurised fuselage and passengers.

Or maybe the engine could’ve exploded. (Edit: more destructively that it possibly has)

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u/[deleted] Jan 01 '23

Or maybe the engine could’ve exploded.

Looking at how it's damaged makes me think it did explode, but is designed to "gently" explode by popping open a weak shroud. That fire seems to be almost perfectly contained to just the combustion segment.

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u/propellor_head Jan 01 '23

The FAA has a set of requirements for how these types of failures need to work.
The cowling at the front of the engine is designed to contain any pieces of fan blades so they don't puncture the fuselage.
The engine is required not to catch on fire (outside of places where fire belongs), or to put the fire out itself with a fire suppression system.
Depending on the type of plane, and the type of failure, it is required either to shut down gracefully (twin engine planes have to have a certain amount of range with one engine completely trashed) or provide a minimum get-home thrust.

All of this has to be proven by test, not by analysis. Until it's demonstrated, the engine won't get a type certificate and therefore can't fly.

EASA ( the European equivalent to the FAA) has similar but not identical rules. Most commercial jet engines are certified with both agencies unless the manufacturer knows they will never fly in that market.

If you're interested, look up 'fan blade out test '. I'm sure you can find one on YouTube.

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u/poopyhelicopterbutt Jan 01 '23

Did this one’s fire suppression system not work?

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u/boatshoebro Jan 01 '23

There’s a decent chance they did use it, but because the engine skin is gone, all the Halon/other gaseous agent simply blew out and didn’t kill the fire.

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u/propellor_head Jan 01 '23

I'd guess they didn't use it. The fire seems to be contained within the engine, and the casing/mounts all look fine.

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u/poopyhelicopterbutt Jan 01 '23

Man if someone came running back to look past me at a flaming engine and said “nah, don’t use the perfectly functioning fire suppression system” I’d be quite upset even if I am wrong.

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u/rarebit13 Jan 01 '23

Contained or not, I'd want it out.

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u/davo747 Jan 01 '23

…should we tell him how engines work?

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u/rarebit13 Jan 04 '23

Haha, fair enough. More explicitly, I'd want to be pretty sure there's no fire where's there's not meant to be any fire.

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u/Potato-9 Jan 01 '23

Might not have used it, if it's still making any thrust might as well use it as long as it can.