OBK's post stated he had shut down the engines, and turned off all the electrical loads, but had left the master switch on. This would mean the electrical gyros were still powered. He did not state which gyros were running down, so the inference to draw would be that they were the vac driven ones, now deprived of their energy source.
His second question was, how long does a battery last before it 'runs down', by inference after the alternators have ceased to charge. The answer is not very long, and your POH won't be able to tell you because it doesn't know the state of your battery to start with, and doesn't know what electrical equipment has been added, or removed since the airplane was new.So if you are in the air make plans to land asap.
He mentioned ' before it stops the donk'. Fortunately as 'the donk' has magneto ignition, it wont stop just because the alternator/battery/wiring has failed/partially failed.
What has looking out and using a GPS got to do with each other?
In event of an electrical supply failure, and assuming you are on a leg of significant distance rather than in your local area, is to turn off everything you can safely do without, and reserve any remaining power for the essentials to come.
Navigating without aids would not be the best way to cope with the situation, particularly if out of sight of the surface, or at night. Using a standby GPS allows most of the avionics to be turned off to preserve power for the radio calls ahead.
Using what is available is called CRM.
Last edited by bluskis; 28th June 2003 at 08:31.