Emergency Config agro!

[Jonny Foreigner]

Afternoon folks,

A320 series. (Edited post).

Can anyone shed light on how the :mad: the gear is raised during a Go-around when in emergency electrical config? :ugh:(However undisireable).

Its my understanding that the green and yellow hydraulic engine driven pumps require the DC bus 1 and 2 to be respectively powered for their operation. Obviously they are not when in this condition.

Thanks folks.

JF.

[mini-jumbo]

It would help if you told us the type you are refferring to.

Why would an engine driven hyd pump require an elecrical bus for its operation?

[Jonny Foreigner]

Good point-well made! A320, as edited.
The manual states that for operation of the ENG 1 driven pump control and ENG 2 driven pump control, in normal circumstances require a power supply to DC bus 1 and 2. In emergency elec config these are not supplied.
When you develop this, the landing distance requirement is huge! Suggesting that there is a lack of both green and yellow hydraulic pressure????????

[Conan The Barber]

I hope you are not A320 type-rated Jonny!

Consider this; Could an airplane - which has non-reversible flight controls - be certified if loss of normal electrical power, causes you to end up on nothing but one hydraulic system powered by a RAT?

Could it be that the electrical supply to the EDPs are for dumping/depressurizing them?

Could it be that if digging a bit deeper in the manual, you will discover that in emergency electrical configuration the anti-skid and ground spoilers are lost? Would that lead to an increase in landing distance?

[twitters274]

Bit harsh of a reply, having looked at the manuals it is a little unclear why certain things happen on this mysterious aircraft. For instance I understand you lose anti-skid due to 2 & 3 ADIRS being off in the Emerg Elec Config but why whilst on the ground do you only get NO 1 Reverser if the EDP's are still working, presumably working on the blue system but why?

[mcdhu]

From memory, in Emerg Elect Config, ldg dist factor is x2.6. Using 900m from Sect 4 of the QRH, that gives you a LDR of 2340m - unfactored!! Apply, say, 15% to get 2691m. Mainly due to no antiskid, Flap 3 ldg with accumulator braking (1000psi max) loss of some spoilers and a reverser - you need a long runway!!

Cheers,
mcdhu

[Jonny Foreigner]

Thanks mcdhu. I understand that, but am still alittle fuzzy on how the gear is raised after a G/A when in emergency electric config? Is it achieved via the EDP? If so then why are so many other green (and yellow) supplied services lost?

Conan, any chance of a straight forward informative answer? After all this is the tech forum.
"Could it be", you are one of those trainers that people are reluctant to ask a question of for fear of that kind of response?

[Dan Winterland]

I think you raise the gear lever - and the gear comes up! Worked last time I tried it in the sim (about 4 months ago).

But on the aircraft with the older RATS (min speed 140 knots - you can tell because CBs D02 and F 07 are yellow collared) the DC ESS BUS is on the batteries as is the AS ESS BUS through the static inverter, tou have to switch them back to the emergency generator by selecting EMER ELEC PWR to MAN ON.

This tells me that the gear is actually electricly powered by the DC ESS BUS - which makes sense if you think about it.