Operation of Systems

Question 1

What are the primary flight controls?

Answer 1

Ailerons, Rudder, and Stabilator

Question 2

Describe the Ailerons.

Answer 2

Differential: which means the aileron deflected up will travel farther than the aileron deflected down.
Frise: which means the aileron pivots on an offset hinge which pokes the leading edge out causing more drag, and creates a slot which air flows smoothing, increasing effectiveness at high AOA.

Question 3

How many degrees in both directions does the ailerons deflect?

Answer 3

Upward: 23 degrees
Downward: 17 degrees

Question 4

Describe the rudder in terms of the anti servo tab.

Answer 4

The rudder has an anti servo tab, this tab decreases the sensitivity and also acts as a trim tab.

Question 5

Describe the stabilator and its anti servo tab.

Answer 5

A stabilator is an all moving slab type so that means the whole thing moves not just a section. Stabilator are very sensitive. The anti servo tab reduces sensitivity and acts as our trim.

Question 6

How are the flight controls actuated?

Answer 6

Through a cable system made up of gears, chains, cables, pulleys, bellcranks, pushrods and counterweights.

Just say through a cable/ pulley system.

Question 7

What are the secondary flight controls?

Answer 7

Trim and Flaps

Question 8

What is the purpose of trim?

Answer 8

Trim is used to relieve the pilots need to maintain constant pressure on the flight controls, designed to minimize pilots workload.

Question 9

What is the purpose of flaps?

Answer 9

Used to increase lift with lower airspeeds. They increase both lift and drag at any given angle of attack.

Question 10

What kind of flaps does the PA-44 180 have?

Answer 10

Plain flaps for the first 10 degrees, then slotted for flaps 25 and 40.

Question 11

What are the different kinds of ailerons?

Answer 11

Differential- moves the downward aileron less than the upward aileron which decreases adverse yaw.
Frise type- aileron being raised pivots on an offset hinge which puts the leading edge down into the wind which creates more parasite drag and reduces adverse yaw.
Coupled Ailerons and Rudder- they are linked controls which when aileron is put in, it automatically corrects by apply rudder, to help fight adverse yaw.
Flaperons- combine both flaps and ailerons. Which can be lowered to function like flaps.

Question 12

What are the different kinds of flaps?

Answer 12

Plain- Most Common. Simply deflects downward to produce more life and drag.
Split- Deflected from a lower surface of the airfoil. Produces a little more lift than plain.
Slotted- Most popular. Increases lift significantly more. A duct between the wing and flap forms, allowing airflow to smoothing flow through, which delays separation and creates more lift.
Fowler- It slides backwards instead of rotating on a hinge, this creates a great deal of lift by increasing the area of the wing and changing the camber of the wing, creates little drag.

Question 13

Describe the PA-44 180 engines.

Answer 13

Rated at 180hp at 2700rpm
Lycoming
Horizontally opposed
Air cooled
Normally aspirated
Direct drive, prop is mounted to crankshaft.

there is one O-360-A1H6 and the right engine is LO-360-A1H6 which mean the prop is spinning to the left.

Question 14

Describe the oil system.

Answer 14

Wet Oil system, which means the oil is held in the crankcase. Max oil is 8qts and min oil is 2qts or 6.5 for ATP. Oil dipsticks are not interchangeable.

Question 15

What are the purposes of oil?

Answer 15

Clean, Lubricate, cool, seal.

Question 16

What kind of oil does the seminole use?

Answer 16

Ashless dispersent which helps clean the system. Its an amber color.

Question 17

Describe just the propellers.

Answer 17

Propellers are 72-74 inch, counter rotating, constant speed, full feathering, Hartzell props.

Question 18

Describe the Prop governor.

Answer 18

The prop governor is connected to a speeder spring connected to a disc that sits on top of fly weights. The flyweights move in and out which either opens of closes the pilot valve which changes the blade angle and thus RPM.

Question 19

Describe what it looks like with more oil pressure in the prop and less oil pressure in the prop.

Answer 19

More oil pressure= lower AOA, higher rpm

Less oil pressure= High AOA, lower rpm

Question 20

What three forces constantly act on the prop to put it into a Feathered position.

Answer 20

Nitrogen, Hub spring, Counterweights.

Question 21

How does the prop know if it is in an overspeed or underspeed condition?

Answer 21

The flyweights are connected to a rotating disc, which is synced to spin at specific speeds with the propeller.

Question 22

Describe an overspeed condition.

Answer 22

Flyweights out, oil out.

Question 23

Describe an underspeed condition.

Answer 23

Flyweights in, oil in

Question 24

What does the unfeather accumulator do?

Answer 24

Stores oil under nitrogen pressure to provide an initial kick for the oil to enter the prop hub.

Question 25

Why doesn’t the prop feather below 950 rpm?

Answer 25

Because of the centrifugal stop pins, so props do not feather and it is less stress on the starter.

Question 26

Describe the Landing Gear system.

Answer 26

Tricycle gear, fully retractable, its electrically activated but hydraulically actuated. The gear is held up by hydraulic pressure. The Hydraulic Reservoir is located behind the baggage compartment.

Question 27

What three reasons will cause the gear horn to go off?

Answer 27

Throttles below 14” of MP, the gear is not down and locked with flaps set to 25 or 40, and if the gear handle is put into the up position on the ground.

Question 28

Describe the squat and up/down limit switches.

Answer 28

Left Squat switch: prevents gear retraction on ground.
Right Squat switch: prevents stall horn and manages on/off time.

Microswitch in nose: activate blower fan on ground

The down limit switches will activate the green down and locked lights and turn off the gear pump.

The up limit switches operate the gear unsafe warning light.

Question 29

Describe the brake system.

Answer 29

Two Disc hydraulic brakes on main wheels. Four separate master cylinders on each pedal. The hydraulic reservoir is located in the nose. Hydraulic fluid is non compressible.

Question 30

Describe the Electrical System.

Answer 30

Two belt driven 14V, 70amp alternators. One 12V 35amp battery located in nose compartment.
Its power is distributed through several buses.

Question 31

What does the Voltage regulators do?

Answer 31

They maintain 14V in the system between the two alternators.

Question 32

What does the over voltage relay do?

Answer 32

Takes the alternator offline if it goes above 17V.

Question 33

What are the different Buses?

Answer 33

Use: BATMAN
Battery Bus
Avionics 1
Tie Bus
Main Bus
Avionics 2
Non-essential Bus

Question 34

What is in the Battery Bus?

Answer 34

Controls on/off time, in/out, heater time, clock

Question 35

What is in the Avionics 1 bus?

Answer 35

Comm 1, Nav 1, Transponder, Electrical Trim, Audio Selection

Question 36

What is in the Tie Bus?

Answer 36

ties everything together

Question 37

What is in the Main Bus?

Answer 37

fuel pumps, panel lights, switch lights, nav lights, landing lights, pitot heat, stall warning, landing gear pump, tachometer, Annunciation panel.

Question 38

What is in the main Avionics 2?

Answer 38

Com 2, Nav 2, ADF, Marker Beacon

Question 39

What is in the Non-essential Bus?

Answer 39

Stand by lights, Recog lights, Cabin Heat, Cabin vent, Blower fan

Question 40

What are the differences between fuses and circuit breakers?

Answer 40

Fuses burn out and have to be replaced, whereas a circuit breaker can be reset only once and you must wait 2-5 minutes for cool down.

Question 41

Describe the ignition system.

Answer 41

A magneto(spinning magnet the creates a current) sends a spark to the spark plugs which ignite the fuel/air mixture in cylinders. The battery provides power for the starter.