Before you get too excited about FAR part 23, remember most of the planes we fly were certified under CAR 3, and don't have to conform to part 23 regarding fuel gauges. Only newer aircraft certified under part 23 have to conform to this regulation.

That's not to say that it isn't a very good idea to get your gauges calibrated and make them as accurate as possible. And if your fuel gauge says empty, then land ASAP and figure out the problem.

John


[quote=Bob Moore;269828]"Gene Seibel" wrote

The only regulations for fuel gauges are that they read correctly at
empty. They are not reliable for determining the amount of fuel in the
tanks, but as they approach empty, they should be believed.

Bull****! I am repeating an e-mail that I sent to a young man
who posted the same information on his web site.

Russ......

I stumbled on your web site while searching for some C-172 Fuel Cap
information.
I found the following statement which while completely false, seems to be
circulating quite widely.

"The FAA only requires the gauges to read accurately when the tanks are
empty. Yeah, you're right, that's really stupid, but it's the law."

I have quoted the applicable portion of the Federal Aviation Regulation
"law".

Section 23.1337: Powerplant instruments installation.
(b) Fuel quantity indication. There must be a means to indicate to the
flightcrew members
the quantity of usable fuel in each tank during flight. An indicator
calibrated in appropriate units and clearly marked to indicate those
units must be used. In addition:

(1) Each fuel quantity indicator must be calibrated to read "zero" during
level flight when
the quantity of fuel remaining in the tank is equal to the unusable fuel
supply determined under §23.959(a.......