QF engine "explosion"

[Jason H]

Yet again.

http://www.smh.com.au/travel/travel-...511-1ehxp.html

Aircraft was VH-OJH. Flight continued to FRA with VH-OJC inbound from BNE.

[Matt_L]

744 had an RTO in Melbourne today as well operating QF9 to Singapore with about a 4 hour delay. I'm not sure of the reason as of yet but it departed at 730pm as QF9D.

[Brad M]

The passenger may have seen sparks and small flames for a short time in the exhaust area of the affected engine but it was definitely not on fire

so there were flames , but it wasn't a fire...

thats a new one.

[Todd Hendry]

I'm bringing OJH home from Singapore on Friday night. Landing in Sydney at 6am as the QF6005. I don't know what they have done to it. I'll let you guys know if I find anything out.

Todd.

[Fred C]

Originally Posted by Brad M

so there were flames , but it wasn't a fire...

thats a new one.

To the non technical person this does seem like an anomoly.

To explain from a technical point of view.

Inside the jet engine there is a very hot fire burning all the time in the combustion chamber (This a good thing, it means the engine is running). When a jet engine surges / stalls the airflow in the engine , which is normally from front to back, reverses briefly. This allows the flames in the combustion chamber to escape forwards and backwards due to the disturbed airflow and the regular amount of fuel still being added to the engine. This is basically the flames that are seen when the engine goes bang.

The surge / stall / bang of an engine isn't a good thing but it doesn't necessarily mean that the engine is buggered, but if it happens in flight then there is usually something wrong, whether a component (carburettor / airflow controller) or the engine itself.

So basically if the fire you see comes from the core of the engine it is not classified as a fire. If there is a fire from the fuel tubes on the outside of the engine, but under the cowls, that is what as classified as a fire, which can also be extinguished by the fire suppression system on the engine.

I have probably confused you more, but hopefully not. Feel free to ask questions.

No, I don't know what happened to this particular engine, but they did replace it in SIN.

[Jayden Laing]

Since the engine got replaced on OJH, what are the chances of her coming back with the 5th podding engine on board? Or is the damaged engine coming back on freighter?

[Fred C]

Could go either way. If the engine is internally damaged it could go straight to HAESL on a freighter as QF do not overhaul their own engines anymore. There is no point in bringing it back to SYD to send straight back to HKG. So freighter is more likely.

[Philip Argy]

A flame from a surge is no more an engine fire than is the flame from a car exhaust when it backfires. It is obviously flammable vapour burning, which is a fire, but it doesn't constitute an "engine fire".

[Nigel C]

Originally Posted by Brad M

so there were flames , but it wasn't a fire...

thats a new one.

If you re-read the quote you put in, it says there was small flame "but it was definitely not on fire." Phil Argy's post regarding backfiring cars puts it into context nicely I think.

[Mick F]

usually something wrong, whether a component (carburettor / airflow controller) or the engine itself

Turbine engines don't have carburettor's, .

Mick