Yes, the batteries are 88 amp/hour each.
The Dutch Dakota crash was a feathering circuit failure as I recall. Didn't make it through the full report linked above. To feather a prop you push the feathering button in. A holding coil is energzied holding the button in, the circuit is completed and the pump pressurizes oil from a standpipe in the engine oil tank and drives a piston in the prop dome to the feather position. When the pressure in the dome reaches some pressure that P&W thinks is enough to ensure the piston has traveled to its limit, a pressure switch releases the holding coil and the circuit is broken.
To un-feather, again the feather button is pushed in and HELD in with a thumb. All the above happens but when the pressure reaches the switch relief pressure, since the button is being held in, the pump keeps running. At some pressure above the switch threshold, a shuttle valve moves and the oil is ported to the other side of the prop piston and now drives the prop to the cruise or fine pitch range. Then you remove your thumb from the button.
Had the holding coil fry one time during a runup. Normally, you'd push the button and as soon as there was a rpm drop, you pull the button out. We pulled but the pump keep running and the engine shutdown. And then the prop blades started coming out of feather and going back in. The only way to stop the pump was to turn the battery master and other generator off. (Couldn't find the feather pump C/B quick enough.)
Last edited by MarkerInbound; 30th Jun 2010 at 16:12.