I understood there were limits on 4 engine press-on due to engine windmilling.

Never heard of them on the four engine aircraft I fly, and we don't 'press on', we 'continue' if appropriate.

I have heard of engines with a windmilling limitation, but they are relatively few I think.

Interesting, how is that regulated?

carnage

no insult intended! Was thinking of some of the talk after the BA 744 ex LAX.

MarkD,

Must have missed that thread, perhaps you could give us a precis!

Still waiting for a new engine..
An124 carrying the GE couldn't reach AF 777 because of snow.

re Windmilling -
Two aspects:

Safety - even if a windmilling engine should seize, the loads should be negligible compared to an operating engine, for which certification criteria have been demonstrated.

Resulting damage (economic loss) from windmilling - that's a matter between the motormaker and the airline. As long as the crew follows the recommendations, it's up to the engine manufacturer to make good any adversely-affected hardware.

woody
http://www.pprune.org/forums/showthr...indmilling+LAX
http://www.pprune.org/forums/showthr...indmilling+744

Pretty good windwilling exchange on p.7 of the latter thread (above)

Ah yes, it's the Russian winter. Didn't the French learn anything from Napoleon about the issues ......

Re: AF 777
 

Stage 1 of the HP compressor had a blade failure I 'm led to believe, the engine has just reached GE Wales O/H facility, so it will soon be known for certain after teardown.

Re: AF 777
 

I find it interesting that the ETOPS failure mode in this thread only refers to engine failures :confused:

During the test program one one of the 7's ( 767/777 ?)
They suffered a failure of a fuselage pressurisation Non return valve which not only got them down from flightlevel tremendous very quickly but on one of them ( I think there were 2 incidents) put some of the crew in hospital:uhoh:

Of course the valve has been modified so this cannot possibly happen again :)

Re: AF 777
 

"I'd prefer to continue to CDG in the triple7 on one.."

That was halarious. I just about spit up my tea when I read that. :} :} :}

Its not that I think Russian carriers are unsafe, but the tought of riding in a converted military aircraft across Siberia in the winter is somewhat uncomforting.

Reminds me of when I went to Peru. I chose the airline very carefully when it came to buying a ticket from Lima to Cuzco. We finaly decided on TACA after looking at equipment type and age. When I was in line to board the brand new A320 we passed one of Aerocontinente's geriatric 737s with built in airstairs and fuselage painted by hand. I really felt that I had made the right decision. But I digress... :=

Re: AF 777
 

Just a quick question re the previous ETOPS debate-are we talking about a least worst scanario or worst worst (as in preasure loss) becasue that makes quite a difference in performace and altitude calulations-25k v 10k and associated fule burn-the 207 min across the pacific on a least worst is fine-BUT-loss of preasure and then what?

Re: AF 777
 

Excellent point, in that case the "cure" may do more damage than the "disease"...

Re: AF 777
 

I would have thought the worst-case scenario. When we fly a sector with an ETOPS part near the end of the flight, we often carry extra fuel to cope with flying low level from the critical point onwards. The AF 777 in this thread might actually have been flying non-ETOPS as there are normally enough airfields across Siberia to do this.

Re Windmilling
 

Our Trents have a 7 hour windmill limit but that assumes that there is no oil or oil pressure available. If the engine has been shut down for reasons other than loss of oil/ oil pressure and the windmilling is producing some oil pressure then there is no limit.

Re: AF 777
 

Interesting pictures about the engine replacement to be found here :http://airvb.free.fr/irk/irk.htm
Not much fun when the temperature drops to -34° c !

Re: AF 777
 

finessemax, thanks for the link. I am impressed! Congratulations to all involved. (When did this happen? I would certainly like to read the story if someone who was there decides to write about it.)