The RV-12 has a mechanical fuel pump on the engine and an electrical
fuel pump near the fuel tank. The electric fuel pump runs continuously
whenever the master switch is on. There is no discrete switch for the
electric fuel pump. The pre-flight check is to turn on the master
switch and observe the fuel pressure to be sure the electric pump is
working. Then start the engine and watch for an increase in fuel
pressure to be sure that the mechanical fuel pump is also working. Yes,
it wastes electricity and wears out the electric fuel pump. On the
other hand, most automotive fuel pumps last the life of the vehicle.
Airplanes are used a lot less then cars. I would not expect the
electric fuel pump in the RV-12 to wear out soon. The big advantage of
wiring the electric fuel pump to run continuously is that it helps to
prevent mismanagement of the fuel system, a major cause of accidents.
The RV-12 fuel system does not have a fuel selector valve because there
is only one fuel tank. There is no mixture control. The only thing for
the pilot to mismanage is the emergency fuel shut-off valve handle that
is located on the floor. The handle must be pulled up to shut off. The
simpler the system is, the less chance for malfunction or error.
Joe
