Piper Cherokee

Use of the mixture control in cruising flight reduces fuel consumption significantly, especially at higher

altitudes. The mixture should be leaned during cruising operation above 5000 ft. altitude and at pilot’s

discretion at lower altitudes when 75% power or less is being used. If any doubt exists as to the amount

of power being used, the mixture should be in the full “RICH” position for all operations under 5000 feet.

To lean the mixture, disengage the lock and pull the mixture control until the engine becomes rough,

indicating that the lean mixture limit has been reached in the leaner cylinders. Then enrich the mixture by

pushing the control towards the instrument panel until engine operation becomes smooth.

If the airplane is equipped with the optional exhaust gas temperature (EGT) gauge, a more accurate means

of leaning is available to the pilot. For this procedure, refer to the “Avco-Lycoming Operator’s Manual.”

Always remember that the electric fuel pump should be turned “ON” before switching tanks, and should

be left on for a short period thereafter. In order to keep the airplane in best lateral trim during cruising

flight, the fuel should be used alternately from each tank. It is recommended that one tank be used for one

hour after takeoff, then the other tank be used for two hours: then return to the first tank, which will have

approximately one and one half hours of fuel remaining if the tanks were full at takeoff. The second tank

will contain approximately one half hour of fuel. Do not run tanks completely dry in flight. The electric

fuel pump should be normally “OFF” so that any malfunction of the engine driven fuel pump is

immediately apparent. If the signs of fuel starvation should occur at any time during flight, fuel

exhaustion should be suspected, at which time the fuel selector should be

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