Operational Tips & Tricks

There was a discussion at the club meeting yesterday about a "Fuel Qty Mismatch" warning that came up on the EDM900 engine monitor in 9RN.  Some, dare I say, boisterous conversation ensued about what exactly we are being warned about when that pops up, and why it happens.  Since some members seem to have a curiosity regarding how much fuel is contained in the airplane around them, I did some digging.  

A little research and a call to JPI came up with the following info:

"Fuel Qty Mismatch" occurs when the measured fuel quantity in the tanks ("FUEL QTY GAL" display in 9RN and "FUEL QTY" in 26Y) is different from the calculated fuel remaining as displayed by the EDM ("REM" in 9RN and "Est REM" in 26Y).  If these differ by more than 10%, it should trigger the warning.

The calculated fuel remaining is derived from the "REFUEL?" gallons number entered…

The left interior light dimmer knob is not properly secured (will come loose in your hand). Please take note of this and DON'T lose the knob. We have a replacement, but installation requires removing the panel and that is a lot of work (read: $$$$$$) so we've elected to defer replacement until the panel is going to need to be removed for another reason, as well.

Outside Air Temperatures on the G5 and the EDM900 differ by around 8 degrees Fahrenheit. Tested with handheld thermometer - confirmed EDM900 is more accurate, so give it more weight in your decision making, especially if you're near icing parameters.

Here is the article that Tom found about the Cessna uneven fuel burn. It is in the airplane documents under N199RN but I figured I would drop it in here as well.