A320 and ETOPS

[00Viggen]

Hi all,
Was hoping to get some clarification on the A320's electrical architecture when it comes to ETOPS.

My understanding is that in order to avoid the use of ones APU on an ETOPS sector, three independent and continuous sources of power are required. In the case of the A320, this is accomplished as follows:

1. Power from LH engine driven generator
2. Power from RH engine driven generator
3. Power from HMG, coupled to LH and RH pumps

If one engine fails, you still have 1 EDG, and the HMG connected to the good EMP. If both engines fail, you then deploy the RAT to power the HMG.

I'm really hoping someone can clarify this third method for me... Is my top level description correct, or am I missing something crucial here?

Cheers,
00Viggen

[Slasher]

Cant get the drift of your question but for ETOPS
the following are required servicable by my outfit.

2 eng-driven gennys
1 APU
1 Emer gen (no-go in any case)

The emer gen is only a last-ditch stay-alive generater in
case of double-genny or double engine failure, and never
assumed to replace say an APU inop at dispatch.

Whats a HMG?

[smudgethecat]

We dont operate the A321/320 ETOPS, however i very much doubt if it could be released on a ETOPS sector with a u/s APU, further by the HMG i assume you mean the CSM/G, this is powered by the blue hyd system which doesnt use EDP,s it uses a AC pump, in the event of total AC bus failure the rat will then power the CSM/G via the blue system

[HM Gypsy]

My outfit allows 4 ETOPS sectors with inop APU.