Originally Posted by Snowflake
Having now flown with a red cube measuring fuel flow, and having seen how accurate flow measurement can be, I don't think i'd put level senders in tanks at all if I could avoid it. One red cube in each wing root, dip the tanks before each flight, and you'll know fuel level more than accurately enough for VFR operations. The only downside is that it requires remembering to set the totals when you fill or top up the tanks.
Careful here. Fuel flow senders are only as good as the assumptions they operate under, specifically:
- You start off knowing how much fuel is in the plane.
- The fuel that leaves the tanks only goes to running the engine (this is the one that bites you).
For my planes the flow sender is what I use to know fuel remaining to the 1/2 gallon. The floats are calibrated to provide an accuracy of a gallon (when in the reading range) so are perfect to backup the fuel totalizer to make sure I’m not loosing fuel (or the tanks really were topped off at the last fill).
I got burned on this once - the float senders provided truth.