Check your gas.

On Dec 1, 2:09 pm, "vaughn"
wrote:
"Ken S. Tucker" wrote in ...

Well for small a/c (I'm Cessna 152), I fill my own and
check for water and of course color.
Otherwise, read the meter of the gas input or trust the
fella loading you.

No way! (I suspect Ken is another who flies about as much as Mx) I don't care
if you watched the guy top off your tank and now both guages read full. The
wise pilot still visually checks the fuel level before flight (eyeball, finger,
or dip stick). While you are at it, make sure that both filler caps are on
tight.

Every Flight Manual has a fuel consumption rate graph
as a function of power/rpm/cruising speed, so at flight
planning, a time and range can be estimated that does
not rely on the fuel gauge, which is accurate to +/- 10%.

I would LOVE to have a Cessna with a fuel guage that was accurate to +/- 10%.
On every Cessna I have ever flown, the fuel guages were best described as
semi-usless crap. Do I look at them? Yes; because in-flight they are your only
direct evidence of remaining fuel. Do I trust them? No!

So a cross check of a wrist watch with the fuel gauge
is a no-brainer.


Cessna's gauges are maybe within 20% if they're working at
all. Many of them are out of calibration when we work on them.
They're supposed to read Empty when the level is down to the unuseable
fuel level, but sometimes they're reading empty long before that. And
some won't reach the full mark even when the tanks are full. And
there's isn't a lot you can do to fix such problems aside from bending
the float wire a bit. And some floats develop leaks that make them
ride lower in the fuel and eventually sink. If the float wire stop
tabs aren't set properly the float will tap on the tank's top or
bottom and get a hole worn in it.

Dead gauges are illegal. They're not a deferreable item as some
other instruments are. There's a common misconception that they only
have to read Empty when the tank is empty, so dead gauges are OK. But
if you read the law as it's written, they must be working.

Any properly trained pilot knows that you must dip the tanks with
a calibrated dipstick before flight. Trusting the fuel delivery guy is
making the assumption that you had a certain level before filling. And
the dipstick must be calibrated to read empty when the tanks still
contain the unuseable fuel specified in the TCDS. Unuseable fuel is
more than the fuel in the lines or whatever; it's the fuel that won't
reach the tank outlet when the aircraft might be very nose-low (full-
flap approach) or in a Vx climb. Many outlets are halfway back along
the length of the tank, and all are above the bottom a bit so that
dirt and water doesn't get into the system. If your dipstick thinks
the bottom of the tank means empty, it's inaccurate. A dead engine on
approach is the usual, eventual result.

POH fuel consumption figures are predicated on aggressive
leaning. Few PPL's I've encountered do that, so the engine is using
more than they think. And how many know how much fuel the thing is
using in the climb? It's a lot more than cruise figures.

As for the most common causes of engine failure, fuel starvation
is the second most common. Carburetor ice is the most common, by a
wide margin. There's far too little training given on the phenomenon.

Dan