Hi Sirani,
Thanks for letting us in on your experience.
In my opinion it was a good idea to RTB. In another thread about this same topic is a link to an accident report of an AA 757 who lost all battery power after electing to continue in 2008. When the battery is dead you lose a lot of systems. I think you would enjoy reading the report in the other thread even though it was in a 757.
Cheers

Framer,

Found this on the net .. don't know how authentic it is but gives a list of what is powered by what...

http://www.sjap.nl/NG%20Electrical%2...20Services.pdf

I agree coming back was the right thing to do especially with CAT 3 conditions in Delhi. Read the report on the B757, thanx. Scary.

Hi Sirani,


I think the Battery Bus will still remain powered if you lose transfer bus 2 and the battery is discharging. The key busses you will lose are the Hot Battery Bus and the Sw. Hot Battery Bus. In this situation your decision was good if you were in a single battery equipped aircraft. In a dual battery aircraft both buses should remain powered via the aux. battery charger. The system will last much longer than the 30 mins. as quoted in the loss of all generators scenario and being on battery power. I have a 737 guide which gives a number of 2 hours but it actually could be quite longer than this if you could minimize the load on the battery. I would treat this scenario as a land soon but not land ASAP. Soon will have a different meaning for each captain. This is why we are paid to make decisions as Captains. Not all things are black and white and this scenario gives you little to no guidance from the QRH. The Transfer Bus off checklist is also leaving you hanging out to dry with little guidance.

A depleted battery will also cause a dual IRS DC FAIL..this will tell you that your HBB and SHBB are dead ..in this case you better get your wheels on earth quickly because if you have an engine or APU fire the only thing you can do is pull the handles and hope for a miracle

Elmok: Many small commercial Aircraft with turboprop engines are not equipped with fire extinguishing systems, e.g., it is an option.

Thing you are getting scared for the wrong reason.

can you dispatch with a 737 without fire extinguishers ? this is not an "option" on a Boeing. a fire under your wings is a serious matter.

Update to my case as you may have known... the battery was just replaced before my flt. It was sent to the manufacture for diagnostics and they didn't find anything wrong with it and engineering insists the charger was connected properly. I think its being covered up by my company. No further action. But they are happy i came back.


Dear WYOMINGPILOT,

even with a 2 battery a/c the aux battery only couples when there is loss of a/c power. but here a/c power is available so the aux battery probably won't connect and u have power only from one batt

??????

Dear elmokh,

Thanx.. i really didn't want to find out what would and wouldn't have worked if the battery went dead..

but a dual IRS DC Fail.. scary...:uhoh:

Not sure I follow you there. With AC power there would be no impact on an otherwise normal operation.

Some previous colleagues had a dual IRS DC Fail and continued flying for quite some time.
It was a battery overcharge condition that, according the engineers, would have exploded if it was left much longer.
(It was a 73 classic)

The important point we've got to is once the battery runs out the ability to fire the squibs and put out engine fires is lost. Err, I think that would make my mind up on it's own.


30 minutes at normal loading is going to mean a lot longer at a light discharge, but the light doesn't come on for light discharges......


I think it's time to go take a look in the books again for me..

Did i read somewhere that the spar fuel SOV has it's own small battery in the spar? intended to shut the SOV if the fire handle is pulled without electrical power? (73NG)

Kefuddle,

I guess u r right.. with the DC FAIL and ac power it would still work.

But I didn't want to find out what would work and what wouldn't if the battery failed (depleted).

Spar Valve Battery
 

Did i read somewhere that the spar fuel SOV has it's own small battery in the spar? intended to shut the SOV if the fire handle is pulled without electrical power? (73NG)

There's a little panel at the bottom of the P6 panel that that battery lives behind.

Since it is not an emergency , Call/ACARS your Airline/MCC and ask what they prefer you do,if reasonable do as requested.
CRM is not limited to the flight and cabin crews.

Call/ACARS your Airline/MCC

The majority do not have this luxury.

Strange..last 3 operators I worked for had it.
Maybe its a lowcost airline thing?