Bad fuel gauges?

Look at the Pilot's Handbook of Aeronautical Knowledge, too.

FUEL GAUGES

The fuel quantity gauges indicate the amount of fuel measured by a sensing
unit in each fuel tank and is displayed in gallons or pounds. Aircraft
certification rules only require accuracy in fuel gauges when they read
"empty." Any reading other than "empty" should be verified. Do not depend
solely on the accuracy of the fuel quantity gauges. Always visually check
the fuel level in each tank during the preflight inspection, and then
compare it with the corresponding fuel quantity indication.

Bob Gardner

wrote in message
...
There's an urban legend that the fuel gauge is only required to be
correct for an empty tank. The legend apparently arises from a
bizarre
misreading of 23.1337b1. What 23.1337b1 actually says is just
clarifying that the 'empty' reading must correspond to zero USABLE
fuel, as opposed to zero TOTAL fuel. There is nothing whatsoever to
suggest that non-empty readings needn't be correct--that would be
absurd. (If it were true, a gauge that ALWAYS says 'empty' would be
legal! You could just write 'empty' on a piece of paper and call that
your fuel gauge!)

The requirement for indications of a tank's fuel level (not just on
empty) is stated in 91.205b9, 23.1305a1, and 23.1337b.

Thank you!

What you say makes perfect sense. I'll go look at the regs too.