Originally Posted by
Design Engineer
twincommander, I can only concur with your comments. Earlier in the thread someone posted a list of instruments that would still be available after generator loss. I'm unclear if that was for a 146 or an RJ now. Losing all your EFIS in an RJ would be a scary event, especially at night.
That list was for the RJ. No EFIS with battery only.
All ya got is Standby Attitude Indicator with bars for glideslope and localizer from #1 Nav.
Standby combined altimeter and air speed indicator driven only be pitot static pressure, and a little DC driven panel vibrator to make the thing run smooth.
#1 Com works.
Also, #1 XPNDR, although you lose mode C data. (EDIT: I'm incorrect - No Xpndr w/o Ess AC from either Standby Hyd. Gen or AC source)
You loose pretty much all your instrument backlighting, and flood. It's mighty dark. You'd need a torch.
Also get brake pressure indication as well.
Draw just on battery is about 30ish amps.
The rush to bring the gear down near the end may have been precipitated by the battery power situation. The Emergency Main Gear Assister Jack uses the yellow DC pump pressure, and draws a significant amount of power, up to 60 amps initially. Not something you want to be trying 20 minutes into your 45/30 minute battery reserve.
There is a 'trick' to get essential (EDIT: Essential DC) (you are already at emergency) power off the battery - that is to turn on the Start Master, but in increases draw significantly to 45-60ish amps. Won't get much more than 15-20 minutes with that.
All of this is moot when none if your engines/apu is functioning though to be frank.