a330 inop apu
 

can anyone tell me why an a330 with an inop apu under an mel has no cross reference to etops .when a 767 with an inop apu is etops critical?

also whilst the said apu is inop does the aircon packs fail to run if a cabin door is open on ground as have had a few instances where a cabin door switch goes open and both packs shutdown after pushback and engs running/is this a speed card input and airgrnd input ?

Uh, what?

The APU isn't an ETOPS requirement under the MMEL, but sane people include it as an ETOPS requirement under their own MEL.

Your question about the doors is weird. The APU or lack thereof has no impact on pressurization.

If you have a door showing open after engine start, the airplane won't pressurize period. That's why we have procedures to bypass a dodgy switch.

Hit the books Kiddo.

PB

maybe i didnt explain myself .
the apu runs the packs on the ground (yes)
so there must be some logic to allow this to happen with an entry door is open,so is it part of the eng speed cards that once the engs are started that if a door switch shows open the packs shutdown?

also the 767 doesnt need an eng run after a mag plug inspection but the a330 does both twins,both subject to etops, so why no apu etops on the 330

finally not rated on the A330 just a curious question

It's an "engine running" logic.

That's what keeps the airplane from pressurizing on the ground with a door open.

The APU is not considered an "engine".

I have no idea why one airplane has a leak check requirement after an MCD pull and another one does not. ANY Engineer worth his salt is gonna look anyway.

PB

thanks
 

thanks pb for the info ,but you are not applying that the aircraft would pressurize with a door open ?,it seems a strange setup on the bus thats all, if its not boeing im not going cheers

Hey Alli I hope you aren't on the Rohipnol so you remember this :ugh:

The A330 has larger Gens/IDGs at 115KVA with a more sophisticated load shedding system, if 1 IDG is lost the remaining can still power the aircraft systems with some service buses or feeders still operating eg some chillers some ovens and water boilers will still operate. So if the APU is inop the A330 will operate fine on one IDG except the inseat video MAY be shed and the pax won't be happy.
To supply an independant power source or complete power in case of dual IDG failure for auto pilot auto land the aircraft is fitted with a HMG capable of supplying 11KVA loads, so the A330 is more relient on Eng Driven Hyd pumps (Check the mel for an EDHP) than the 767 which is relient on the apu to supply electrical power to provide backup. So while the A330 apu inop is a 10 day mel it does not effect ER ops


If the A330 is on the ground, an entry door, cargo door is not closed and an engine is running the aircon packs will not run. Makes it a biatch to cool a cabin with a dead apu and no aircon carts.
Yes the inhibit comes from the Engine interface box and airground.

The leak check requirement on the MCD on the bus sounds like GE trying to prevent any more IFSD as it has a shocking record on the bus with well over half dozen this year.
:ok:

All this is from memory if clarification is sort I may have to do some reading

Ah Bolty McBolt,
That there is a great post and the reason I love trawling "Tech Log". Eventually someone will come along and be able to give a no-nonsense, concise and direct response. You included all the points required and the reasons for them! Go to the top of the class!!

:D :D :D :D

thanks bolty that was exactly the answer i was looking for,might even be a bus convert in the wings cheers

Just to add to Bolty's excellent post.

The Bus also has two hyd pumps on each engine and elec hyd pumps as backup. Whereas the 767 with only one pump on each engine more critically requires elec pwr to run backup elec hyd pumps.

I think. I'm not rated on either a/c just going on past experience.