pitch for higher rpm. Moving the power lever aft increases governor oil pressure
which increases propeller pitch for lower rpm. During stabilized flight, the
governor adjusts propeller pitch in order to maintain a specific rpm.
121. Describe the basic fuel system: A vented fuel tank and a fuel collector
tank/sump in each wing, a three-position valve, an electric boost pump, and an
engine-driven fuel pump. Excess fuel at the engine driven fuel pump is routed
back to the selected fuel tank through fuel return lines and the fuel selector valve.
(Note; the key for the lockable fuel caps is located in the arm rest storage box).
122. Describe the fuel venting system: The collector tank is vented into its
respective fuel tank, which is vented to a NACA-type vent mounted underneath
the wing near each wing tip.
123. What are the locations of the fuel drains? Five total: One under each fuel
tank, one under each collector tank/sump, and one under the gascolator, which is
below the lower engine cowl just forward of the firewall.
124. How much useable fuel exists if the tanks are filled to the tabs? 26 gallons, 13
in each fuel tank.
125. Left fuel tank is empty; right tank has 10 gal. Will the FUEL caution light be
on? No, both tanks must have approximately 8.5 gallons for the light to activate.
126. What problem can occur when the fuel tanks are ¼ full or less? Prolonged
uncoordinated flight such as skips or skids for more than 30 seconds can
uncover the fuel tank outlets and cause fuel starvation.
127. What is the proper use of the boost pump switch? For engine starting,
pressing PRIME (a momentary position) causes the boost pump to operate at a
high speed until the fuel pressure reaches 2 to 4 psi. When that pressure is
attained, the boost pump automatically switches to the low speed BOOST mode
(a selectable position) to provide a 4 to 6 psi fuel pressure boost. For vapor
suppression with hot fuel, select the BOOST position, which provides a 4 to 6 psi
fuel pressure boost. Select the BOOST position for takeoff and landing.
128. Refer to Figure 3-2 on page 3-26 of the POH, and describe the electrical
system: There are two batteries and two alternators. BAT 1 and ALT 1 supply the
main distribution bus which powers MAIN BUS 1, MAIN BUS 2,
NON-ESSENTIAL BUS 1, and NON-ESSENTIAL BUS 2. BAT 2 and ALT 2
Cirrus SR-20 POH Summary
Page 12 of 18
