Aircraft Systems

Question 1

What is the maximum output (hp) of the engines is ____ at _____ RPM?

Answer 1

180 hp, 2700 RPM

Question 2

What is LHAND?

Answer 2

L - Lycoming
H - Horizontally Opposed (cylinder heads)
A - Air Cooled
N - Normally Aspirated (no turbo charger)
D - Direct Drive

Question 3

Name two facts about the oil system.

Answer 3

Each engine has an 8 quart capacity in a wet sump system and has a dipstick calibrated for that specific engine.

Question 4

Describe the function and operation of the carburetor heat.

Answer 4

• The carb heat reduces the possibility of induction system icing.
• Placing the levers down (ON) causes heated unfiltered air to enter the induction system alleviating the potential for icing.

Question 5

What do the cowl flaps do?

Answer 5

• Changing position (CLOSE - HALF - OPEN) of the cowl flaps can help maintain the desired cylinder head temperatures.

Question 6

Describe the operation of the magneto/starter switches?

Answer 6

• They incorporate a “R”, “L”, and “BOTH” magneto in addition to the “OFF” and “START” positions.
• The switch includes a “PUSH TO PRIME” position that activates the electric priming function to supply extra fuel during engine start.

Question 7

Describe the propellers.

Answer 7

• Two 76 inch Hartzell constant speed, full feathering, two blade propellers.

Question 8

How is RPM regulated.

Answer 8

• RPM is controlled by an engine driven prop governor which regulates oil pressure in the prop hub.
• Speeder springs and air pressure aided by counterweights, move the blade to low RPM (high pitch)
• Engine oil boosted from the prop governor moves the blades to the high RPM (low pitch)

Question 9

What happens when oil pressure is lost (falls below 950 RPMs)

Answer 9

When oil pressure is lost, the propeller will automatically go into the feather position.

Question 10

How many volts is the Duchess’ electrical system?

Answer 10

28 volts

Question 11

Describe the batteries.

Answer 11

• Two 12 volt, 25 amp lead-acid batteries connected in series.
• The battery is used for engine start and emergency power.
• Over-voltage protection is provided if voltage exceeds 31.5 volts

Question 12

Describe the alternators.

Answer 12

• Two 28 volt, 55 amp belt-driven alternators.

- The alternators are completely separate except for the BUS TIE FUSE

Question 13

Describe the flight controls.

Answer 13

• Push-rods and bell cranks.

Question 14

How is trimming the aircraft accomplished?

Answer 14

• Using either the manual or electric trim system

Question 15

What kind of design is the landing gear?

Answer 15

• Tricycle landing gear that is hydraulically actuated and fully retractable.

Question 16

How is the gear held up/down?

Answer 16

• The gear is held up by pressure and remains locked in the down position using over-center link and spring.

Question 17

How is gear retraction on the ground prevented?

Answer 17

• By the ground pressure safety switch located in the pitot system to deactivate the pump circuit when airspeed is below 59-63 KIAS.

Question 18

How does the emergency gear extension work?

Answer 18

• A hydraulic bypass valve is located below the LP floor panel.
• Rotating the valve 90 degrees releases hydraulic pressure and lowers the gear.

Question 19

What kind of gas can the Duchess take and how much?

Answer 19

• 100 (green) or 100LL (blue) aviation gas

- 51.5 gallon total capacity with 50 gallons usable per wing

Question 20

Describe the fuel pumps.

Answer 20

• Two engine-driven (primary)

- Two electrically-driven (used for engine start, takeoff, landing, and fuel selector changes)

Question 21

Describe the brakes.

Answer 21

• Disk brakes

- Hydraulically actuated on the main gear (independent from the landing gear)

Question 22

Where is the pitot tube located?

Answer 22

• On the left wing

Question 23

Where are the static ports located?

Answer 23

• One on each side of the aft fuselage

- Alternate source inside the cockpit

Question 24

For what flap setting does the left stall warning vane sound?

Answer 24

• 0 to 16 degrees of flaps

Question 25

For what flap setting does the right stall warning vane sound?

Answer 25

• greater than 16 degrees of flaps

Question 26

What switches much be on for the stall warning system to work?

Answer 26

• The BATT and ALT switches must be on

Question 27

What is the capacity and location of the environmental system?

Answer 27

• The Duchess is equipped with a 45,000 btu gas heater on the right side of the nose compartment

Question 28

What does the environmental system used for?

Answer 28

• It provides heated air for cabin warming and windshield defrosting