IFR Alternate Requirement

Ron Natalie wrote:
---Never, never rely on fuel gauges as to available fuel, fly by time in
tanks

Always take the more pessimistic view of the guages and your watch.
I've had two friends put down off-field because they had higher than
expected fuel burns (in one case a mechanical failure was found, in the
other, I don't think he'll ever know why the fuel didn't last).

My club has been putting fuel computers into our planes. It's basicly just
an accurate flow meter spliced into the fuel line going to the engine. You
tell it how much you started out with, and it tells you instantaneous flow
rate and how much you've used (or got left). A wonderful tool.

The idea that a watch and a predicted flow rate is your most accurate way
of determining how much fuel you have left is absurd. The only thing
that's more absurd is that GA fuel quantity gauges are so inaccurate that
the watch and predicted flow rate actually is the best way, or at least was
until fuel computers became available.

Roy Smith wrote:
Ron Natalie wrote:

---Never, never rely on fuel gauges as to available fuel, fly by time in
tanks

Always take the more pessimistic view of the guages and your watch.
I've had two friends put down off-field because they had higher than
expected fuel burns (in one case a mechanical failure was found, in the
other, I don't think he'll ever know why the fuel didn't last).


My club has been putting fuel computers into our planes. It's basicly just
an accurate flow meter spliced into the fuel line going to the engine. You
tell it how much you started out with, and it tells you instantaneous flow
rate and how much you've used (or got left). A wonderful tool.

Agree these are wonderful tools. Don't forget they only measure the flow rate
that goes through the flowmeter. A leaking gas cap, for example, can not be
detected by watching your flowmeter. Not implying that you didn't already know
that, of course.


The idea that a watch and a predicted flow rate is your most accurate way
of determining how much fuel you have left is absurd. The only thing
that's more absurd is that GA fuel quantity gauges are so inaccurate that
the watch and predicted flow rate actually is the best way, or at least was
until fuel computers became available.

Experience in the individual airplane or at least in make and model can improve
your ability to predict, but only if you keep records of fuel use. When I
started keeping records, I realized how far off I was in my earlier fuel use
predictions.