"Tarver Engineering" wrote...

And you start with pounds as the basis and convert to have the fuel vended,
no matter what units of volume are used. Then the weight of the airplane is
checked to see if the fuel got onboard.

So, the FE begins with a takeoff weight, calculates the fuel to be ordered
and leaves the weight on the dash for the pilot to cross check.

Nope! It is apparent you don't know at all what you are talking about.

In "a high reliability sysetm" such as that in a 777 or 747-400, the fuel vendor
is simply told the "final fuel" figure in kilograms (or pounds, for those so
inclined). The fueler sets that figure on the aircraft fueling panel and starts
the pumps. The aircraft system shuts the inflow valves when it senses the
requested fuel in the tanks.

The pilot does NO conversion of weight to volume prior to fueling. The vendor
does NO conversion of weight to volume. The vendor produces a receipt that
shows delivered fuel in gallons and/or liters ONLY.

There is no FE in the loop in most current "high reliability [systems]." There
is NO calculation of "fuel to be ordered" -- there is only a calculation of
"final fuel" required.

After the fact, the receiver of the fuel may perform a verification procedure to
ensure the fuel delivered, as shown on the receipt, is accurate. That is the
only time any volume-to-weight conversion is done.