Airport fuel farms are a big variable. At any airport with scheduled
service by a 121 carrier you can be pretty sure of the quality of the fuel
and the equipment as the carriers QA Dept. (My job with one of the big 3 US
carriers) will perform scheduled audits of the farm as well as the into
plane delivery system. For the most part, at least in the US, the farms are
held to the ATA Spec 103 standard. The CASE organization has also developed
a standard similiar to 103 and is being accepted by the carriers who are
CASE members. At a smaller airport I would exercise full caution, waiting a
good 15-30 minutes after fueling or aircraft movement to sump the tanks.
For what it is worth 30 minutes min. is the standard at my carrier.

The FAA has no oversight of fuel farms, there are no FARs addressing them
and as they are not "certificated" the FAA has no enforcement power. Any
discrepancy noted in fueling procedures or quality will result in a LOI or
enforcement action against the operator. So when it comes to fuel the
phrase "let the buyer beware" never rrang truer.

Seth

"Chris Hoffmann" wrote in message
...
"John Harlow" wrote in message
...
(water). I recently witnessed a situation where the fuel was checked
during preflight, but not after refueling.

How then would one know if the tanks were filled with the wrong type of
fuel?

....Now that's an even better question. Thank you!