AviationBanter - View Single Post - Post-Annual Flight

**Ray Andraka** · February 21st 08, 09:30 PM posted to rec.aviation.piloting,rec.aviation.owning

wrote:

If "you can't trust it to within a quarter tank", you should probably
get it fixed.

Yeah, I know, it is common and nobody seems to care, but that isn't
what the regs say.

BTW, if your gauges don't show repeatable indications, it is time to
overhaul the gauges, the senders or both. While the gauges may not be
calibrated to show the actual quantity remaining, the FARs do require
them to indicate accurately at zero (and they generally do if they are
working at all). Regardless, you shouldn't be getting a 1/4 tank
variation from day to day with the same amount of fuel in there. While
the markings on mine don't correspond too well to the actual fuel
quantity, the position of the needle for a given amount of fuel is
fairly constant unless the electrical system is off and the battery
running down (don't ask me how I know that).

Tha FARs basically require the gauge be operating (which means it
increases when you add fuel and decreases when you burn fuel), and that
it is accurate when the tank is empty. There is nothing there about
calibration otherwise, and I'd bet that most of the airplanes out there
have gauges that meet the rules (the exception being those that don't
indicate at all).