Fuel

Question 1

Usable Fuel Capacity SR20 ?

Answer 1

56 Gal

Question 2

Usable Fuel Capacity SR22

Answer 2

96 Gal

Question 3

SR20 Tabs ?

Answer 3

26 Gal (13 per side)

Question 4

SR22 Tabs ?

Answer 4

60 Gal (30 per side)

Question 5

What’s the estimated range of the SR20 for 65% power 8000 feet ?

Answer 5

650 NM

Question 6

Estimated Range of SR22 for 65% power at 8000 ft ?

Answer 6

~850 NM

Question 7

Whats the Flapper Vale do ?

Answer 7

One way valve between main tank and collector tanks.

Question 8

Why are there collector tanks ?

Answer 8

Less sensitive to maneuvers to provide immediate on-demand source of fuel.

Question 9

Describe purpose of the selector valve.

Answer 9

Directs fuel flow from either left or right tank to the electric auxillary fuel pump and gascolator.

Question 10

Describe purpose of gascolator.

Answer 10

Filters fuel down to 100 to 140 microns.

Question 11

Describe Fuel flow leaving Gascolator

Answer 11

1) Then to engine-driven fuel pump
2) To mixture/throttle controlled metering valve (SR22) or Fuel Servo (SR20)
3) To flow divider to proportion fuel to injectors

Question 12

Describe purpose of the Boost Pump

Answer 12

Used for engine priming and vapor surpression. Increases fuel pressure to 23 psi.

Question 13

Describe purpose of fuel relay.

Answer 13

Governs speed (i.e. high/low) of fuel pump based on oil pressure of 10 PSI from EAU.

Question 14

If oil pressure less than 10 psi, does prime work ?

Answer 14

No, pump will only run in “low” i.e. Boost. 23 psi.

Question 15

Describe limits of primary fuel pump relating to atmopheric pressure.

Answer 15

Turbo version will dynamically vary fuel pump pressure based on manifold pressure. Other versions require pilot to control mixture on climb/take-off from high-altitude airports.

Question 16

Describe purpose of mixture control.

Answer 16

controls RATIO of fuel to air to engine.

Question 17

Describe purpose of Power-Lever.

Answer 17

Controls total VOLUME of fuel/air mixture.

Question 18

Where is mixture control connected ?

Answer 18

Fuel Servo (SR20) or Throttle Metering Valve (SR22)

Question 19

How is fuel quantity measured ?

Answer 19

Float sensors in each tank send values to EAU (Engine Airframe Unit)

Question 20

What are the fuel CAS messages that could be received (Cirrus Perspective) ?

Answer 20

1) Yellow L Fuel Qty <8 Gal (SR20) < 14 Gal (SR22)
2) Yellow R Fuel Qty <8 Gal (SR20) < 14 Gal (SR22)
3) Yellow FUEL QTY Both Tanks < 8 Gal (SR20) < 14 Gal (SR22)
4) Red FUEL QTY BOTH TANKS < 7 Gal Total < 9 Gal Total

Question 21

What are CAS fuel messages in Cirrus Perspective Plus ?

Answer 21

1) Yellow Fuel Low Total <10 Gal (SR20) < 14 Gal (SR22)
2) Red Fuel Low Total < 7 Gal (SR20) < 9 Gal (SR22)3) Yellow
3) FUEL LOW L < 1 GAL
4) FUEL LOW R < 1 GAL

Question 22

How is fuel flow sensed ?

Answer 22

A transducer mounted downstream engine-driven fuel pump (SR22) and downstream of fuel-servor (SR20)

Question 23

How do you supress fuel vaporization ?

Answer 23

Boost Pump will increase pressure to 23 psi, which delays onset of vaporization.

Question 24

Does fuel vaporization occur to higher altitudes ?

Answer 24

Yes, it can be more pronounced, especially at high-altitudes on warm days.

Question 25

Describe fuel flow on take-off / climb-out.

Answer 25

Too much fuel flow can create excessively rich mixture, compromising engine performance or cause roughess engine failure.