Posted for MikeEasley@aol.com:

Excuse my ignorance, but is the aneroid bellows that's been discussed the
feature of the fuel pump that richens the mixture at full throttle? What's
been described to me is our engines are designed to add extra fuel when at
full
throttle.

The TSIO 550E at 2,700 RPM should be using between 41.7 and 43.4 GPH
according to the SB. I remember reading that the RPM on the aircraft was
getting as
high as 3,190. The SB also has a chart to adjust the metered fuel pressure
for reduced RPM. If you apply those adjustment factors in reverse to the
fuel flow, the fuel flow numbers for 3,190 RPM and you get 50.9 to 52.9 GPH.

Before someone tears apart my logic, I understand that these things may not
be
linear and the correction factor may not be valid for estimating fuel flow
at
higher RPMs. But if you're turning those RPMs, you certainly can expect a
higher fuel flow, and that the engine can "handle it".

I also read through the Columbia 350, 400 and Cirrus SR22 manuals and they
are set up to use the high boost in the event of a mechanical fuel pump
failure. The low boost is only for vapor suppression, takeoff and landing,
and
fuel tank switching.

Mike Easley