Engine Fire over Denver

[anonymous-user]

stevemcs said:

There isn't a lot left of that, what is it with modern engines when they go bang they seem too lose a lot of the cowling.

er, most of it, mass wise is still there tbh!

Loosing a blade, then getting the windmill shakes and displacing the lightweight, non structural cowels is pretty normal in such events, in fact you want the cowls to break off cleanly if they are breached, rather than flap round in the breeze and cause further damage to the core/pylon/wing etc

And whilst shedding bits in flight that then fall to the ground is of course a risk to people and property on the ground, the probability of actually being hit by said debris is very very low, even in areas of high population density

[carl_w]

Is that engine "on fire" or are we just seeing the combustion process that would normally be hidden by the housing? Obviously the oxygen mix will be wrong hence the yellow flames.

[Mave]

I expect they would have shut the engine down pretty quickly, so there shouldn't be any more fuel getting to the combustor. I wondered if it was due to a run in the compressor, but I think its more likely an oil leak - the engine is windmilling so the oil pump will still be turning.

[5150]

carl_w said:

Is that engine "on fire" or are we just seeing the combustion process that would normally be hidden by the housing? Obviously the oxygen mix will be wrong hence the yellow flames.

Very much doubt the engine was kept running. They had a Fire Warning which you can hear in the transmissions in the YouTube link, so the crew would have have shut that engine down, as per the Engine Fire procedure. My guess would be that as the damage was uncontained, it's then gone and set fire to parts of the engine outside of the combustion chamber.

[anonymous-user]

NTSB calling it an “engine event” - love these aviation euphemisms.

Loss of separation - mid air crash
Runway excursion- went off the runway
CFIT - crashed into a mountain
Hull loss - massive crash

[anonymous-user]

5150 said:

carl_w said:

Is that engine "on fire" or are we just seeing the combustion process that would normally be hidden by the housing? Obviously the oxygen mix will be wrong hence the yellow flames.

Very much doubt the engine was kept running. They had a Fire Warning which you can hear in the transmissions in the YouTube link, so the crew would have have shut that engine down, as per the Engine Fire procedure. My guess would be that as the damage was uncontained, it's then gone and set fire to parts of the engine outside of the combustion chamber.

It might be that the videos showing the fire were taken before the fuel control switch had been shutoff and the engine fire bottles had been discharged also?

Once the fuel and hydraulics valves had closed to the engine and the generators had been shut down plus the extinguishers had been discharged hopefully there was less fire in that area.

Anyone interested in how it all works, there’s an old school Boeing CBT video on the B777 engine fire protection system here.

https://youtu.be/ZmV8SsRHF0I

[Pinkie15]

Have read in a few reports on AAIB site that when the cowling's get shed/ripped off that quite often fuel & /or oil lines often get damaged and continue to flow even though actions are taken to shut the engine down.

Guess this will vary by engine manufacturer and where they site fuel/oil lines and ancillary components.

I was surprised that the first fan seems to be so intact, though hard to see in detail. Primary failure further 'into' the engine ?

Turns a lot faster than I expected for windmilling, too.

[Crafty_]

Not ideal really is it.

At the same time a 747 cargo (Maastrict to New York) had an engine failure during takeoff, bits of blade were distribued over a village in the Netherlands, apparently a lady suffered injuries from being hit with debris.
Aircraft landed safely in Liege





https://avherald.com/h?article=4e35302b

Both incidents are P&W engines apparently, albeit different models.

[Mabbs9]

carl_w said:

Is that engine "on fire" or are we just seeing the combustion process that would normally be hidden by the housing? Obviously the oxygen mix will be wrong hence the yellow flames.

My vote is on fire. Those flames seem to be coming through the thrust reverse ducts rather than the combustion chambers.

They would also very likely to have carried out the engine securing actions by that altitude.

Not a great situation.

[anonymous-user]

Crumpet said:

Interesting that the fire kept burning. Not something you’d want 180 minutes from land somewhere over the Pacific.

I doubt it burned for very long though? Possibly just some residual fuel etc in the engine before and just after it was shut down.

Doesn’t look like the fire spread very far.

In fact this looks like a contained engine event as all the high energy rotating bits like blades etc appear to have remained inside the engine casing (or not penetrated the sides) Obviously that doesn’t help anyone on the ground as the cowl etc hit fell around them.

[anonymous-user]

Mabbs9 said:

carl_w said:

Is that engine "on fire" or are we just seeing the combustion process that would normally be hidden by the housing? Obviously the oxygen mix will be wrong hence the yellow flames.

My vote is on fire. Those flames seem to be coming through the thrust reverse ducts rather than the combustion chambers.

They would also very likely to have carried out the engine securing actions by that altitude.

Not a great situation.

Looks on fire, an engine is always on fire (in side the chambers) but you shouldn’t see the fire like that outside them.

[Scabutz]

Probably a stupid thing to say but seeing the front of the cowling next to the house and truck provides context to quite how fking huge those engines are.

[Crafty_]

There would also be oil that could burn.

Pics of damage from debris:
https://www.thedenverchannel.com/news/local-news/d...

Cowl inlet wrecked that truck it is sat next to:
https://denver.cbslocal.com/2021/02/20/broomfield-...

Just reading up, 2018 UAL1175 had a similar issue, although not quite as dramatic. Oddly it was also flying to Hawaii. It was also one of the oldest B777s with the same PW engines

https://aviation-safety.net/wikibase/wiki.php?id=2...

https://www.magical-planet.com/terrifying-video-sh...

Scabutz said:

Probably a stupid thing to say but seeing the front of the cowling next to the house and truck provides context to quite how fking huge those engines are.

GE9x:


Front fan is 11 feet in diameter, 134,000 pounds of thrust. With all the cowling etc its about the same as a 737 fuselage.
Some of it is made with a big 3D printer https://www.3dnatives.com/en/ge-3d-printing-aerosp...

They had one on display at the Paris air show a couple of years ago, the engine was hailed in to place and the rest of the display built around it. https://www.youtube.com/watch?v=w8fuuHlhjJI

Edited by Crafty_ on Sunday 21st February 12:30

[anonymous-user]

Pinkie15 said:

Have read in a few reports on AAIB site that when the cowling's get shed/ripped off that quite often fuel & /or oil lines often get damaged and continue to flow even though actions are taken to shut the engine down.

Guess this will vary by engine manufacturer and where they site fuel/oil lines and ancillary components.

I was surprised that the first fan seems to be so intact, though hard to see in detail. Primary failure further 'into' the engine ?

Turns a lot faster than I expected for windmilling, too.

Better photo here from later on

[eharding]

El stovey said:

Pinkie15 said:

Have read in a few reports on AAIB site that when the cowling's get shed/ripped off that quite often fuel & /or oil lines often get damaged and continue to flow even though actions are taken to shut the engine down.

Guess this will vary by engine manufacturer and where they site fuel/oil lines and ancillary components.

I was surprised that the first fan seems to be so intact, though hard to see in detail. Primary failure further 'into' the engine ?

Turns a lot faster than I expected for windmilling, too.

Better photo here from later on

Those lighter coloured blades definitely don't look right. Could have been a manufacturing error, and they've actually fabricated those two out of cheese rather than high-end composites?

[anonymous-user]

eharding said:

Those lighter coloured blades definitely don't look right. Could have been a manufacturing error, and they've actually fabricated those two out of cheese rather than high-end composites?

They’re a substitute, according to the Boeing 777 MEL and DDG (minimum equipment list and dispatch deviation guide) you can use the alternative cheese blades for 30 days as long as you don’t use engine anti ice and keep mice away from them.

[Crumpet]

El stovey said:

Crumpet said:

Interesting that the fire kept burning. Not something you’d want 180 minutes from land somewhere over the Pacific.

I doubt it burned for very long though? Possibly just some residual fuel etc in the engine before and just after it was shut down.

Doesn’t look like the fire spread very far.

In fact this looks like a contained engine event as all the high energy rotating bits like blades etc appear to have remained inside the engine casing (or not penetrated the sides) Obviously that doesn’t help anyone on the ground as the cowl etc hit fell around them.

I sort of assumed the photo of it from the ground was back on final approach to land so therefore still burning. However, I guess it would’ve caused quite a commotion on landing though when the fire trucks did their inspection. Was there an emergency evacuation?

[Dogwatch]

Petrus1983 said:

Apparently that weighs about a ton and aerial shots show it obviously used the householder's transit type van roof as a 'soft' landing before bouncing off onto the lawn. And the investigators insist that all debris must not be moved

[eharding]

El stovey said:

eharding said:

Those lighter coloured blades definitely don't look right. Could have been a manufacturing error, and they've actually fabricated those two out of cheese rather than high-end composites?

They’re a substitute, according to the Boeing 777 MEL and DDG (minimum equipment list and dispatch deviation guide) you can use the alternative cheese blades for 30 days as long as you don’t use engine anti ice and keep mice away from them.

I suspect that when the report comes out they'll find the right engine anti-mouse equipment was INOP, or possibly just having a snooze, resulting in rodent-induced holes in the cheese, which then lined up.

You hear about that sort of thing quite a lot in aviation incidents, which now I think about it probably implicates mice in far more accidents then is ever made public - I'm amazed the AAIB, NTSB etc haven't cottoned on to this.

[LotusOmega375D]

El stovey said:

Better photo here from later on

“Ooh look mummy, there’s the ice hockey stadium!”