Piper AZTEC D PA-23-250 Owner's Handbook Manual page 28

THE PIPER AZTEC "D"
SECTION 11
the off position. Electric auxiliary fuel pumps, located in the
engine nacelles, are installed in by-pass fuel lines between the
tanks and the engine-driven pumps. The electric pumps can be
used to provide pressure in the event of failure of the engine-
driven pumps. They are normally turned on to check their oper-
atioo before starting the engines, turned off after starting, to
check engine-driven pumps and left on during take-off and land-
ing, to preclude the possibility of fuel pressure loss due to pump
failure at critical times.
If one of the engine-driven pumps fails, the electric pump
to that engine can be turned on to supply the fuel. However, if
desired, the fuel can be pumped by the operating engine-driven
pump to the failed pump engine simply by turning on the cross-
feed. The good pump will then be supplying both engines from
its tank. If this tank runs low on fuel, fuel can be drawn from the
opposite tank by turning on the electric pump on the failed pump
side, leaving the crossfeed on, and turning the fuel valve on the
empty side off. Then the electric pump on the failed pump side
will be supplying both engines from its tank.
Fuel can thus be used from one tank or the other, by shut-
ting off one main valve and turning on the crossfeed, to balance
fuel loads or for other purposes. For all normal operation, it is
recommended that fuel be pumped directly from the tanks to their
respective engines, with the
crossfeed off.
The fuel valve controls
and crossfeed control are
located in the fuel control
panel between the front seats.
Two electric fuel gauges in
the engine gauge cluster on
the instrument panel indicate
the fuel quantity in each tank.
The electric fuel gauges in-
dicate the fuel quantity in the
tank selected by the fuel
selector handle, located in
680501
Fuel Selector
' 18