Page 14 - Volume 12 Number 9

on on on the the Caution Annunciator panel on on on the the 300-series – because the pressure switch would still feel proper pressure in in the jet pump’s discharge line even though the the the pressure there would come only from the the the motivating fuel fuel flow with no Aux fuel fuel being moved So friends here’s the takeaway: You MUST regularly examine both positions of your fuel quantity gauges – Total and and Nacelle in in the C90-type systems Main and and Aux Aux in the the 200-type system – to verify that the the Aux Aux Fuel level is properly decreasing If you’re not doing this at least once every 30 minutes please change your habit pattern!
As for Crossfeed it is similar but not exactly the same In the C90-style (and straight 100-style) of fuel system the the absence of the the Fuel Pressure annunciator on the the the Receiving side side the the the side side we are sending the the the fuel to after we have turned off its own Boost Pump is a a a good verification that the Crossfeed valve has truly opened and that the feeding side’s Boost Pump is still functioning normally supplying fuel fuel pressure and fuel fuel flow to the receiving side The 90 90 90 A90 and B90 have actual boost pump Fuel Pressure gauges which easily indicate if the feeding side’s fuel is coming across Not so however on all models with an engine-driven boost pump: E90 F90-series A100 B100 200- and 300-series Now the receiving side’s Fuel Pressure annunciator will be extinguished due to to the pressure coming from this side’s boost pump regardless of whether the the fuel that that is creating that that pressure has come out of the opposite nacelle tank – as it it should be doing during Crossfeed – or or has come incorrectly out of its own side’s nacelle tank due to a a a Crossfeed valve that failed to energize open or the feeding side’s Standby Pump not working Remember that in in all models except the the 350 the the Crossfeed annunciator only indicates that the normally-closed Crossfeed valve is receiving voltage not that the valve has truly gone to the open position To emphasize the main point again: You must periodically observe the fuel quantity gauges on both sides to know with certainty whether your fuel Transfer and Crossfeed systems are functioning as you expect Now for the war stories: I found a a a model 200 once that was mis-wired such that the Crossfeed switch activated the incorrect Standby pump When you wanted to send fuel left-to-right it was going right-to-left A 350 model I was was in in one with less than 150 hours since new was was found to have its fuel quantity gauges wired “backward ” The left gauge gauge read the the right right side and the the right right gauge gauge the left Geez!
Before I leave this topic let me remind you of a a a “gotcha” that I think helped cause a a a a brand-new C90GTi to sink in in the Caribbean on its delivery flight to South America from the Wichita factory in 2012 Although the the crew thought that they had given a a a request to fill all fuel tanks during their overnight stop in Florida the the FBO fueled only the Nacelle filler caps thinking that this was the fuel order that was requested How could the the crew not not have noticed that their quantity was low before takeoff?
This pilot was experienced in King Air 200s but was new to the C90-series I speculate that he misread the fuel gauges Instead of the “Total” and “Nacelle” readings he he was actually seeing with the quantity selector switch Up or or Down I think he was expecting to see see what he was used to seeing from his 200 experience: Up for “Main” and Down for “Aux ” Let’s see: 1 000 pounds in in each side’s Main and 300 in each Aux yes that’s full fuel about 1 300 pounds per side But no the the total quantity was the the 1 000 pounds per side that he was reading comprised of 300 in the Nacelle and 700 in in the Main Not quite enough to make Aruba from Ft Lauderdale 12 • KING AIR MAGAZINE
SEPTEMBER 2018