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Multi-Engine Lab (325) > Systems and Vmc > Flashcards

Flashcards in Systems and Vmc Deck (53)
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1
Q

What does the Prop Governor do, and how does it work? (draw a picture)

A
  • Controls the pitch of the prop blades to maintain a constant speed!
  • Wire from prop levers is connect to a spring that adjust pressure on the Pilot Valve/Counter weights
  • The Pilot Valve moves up when Counter weights move out, allowing more oil to pass to the prop shaft
  • When Pilot Valve moves down and the Counter Weights are in, less oil is allowed through
2
Q

Why do we check prop feathering at 1500 rpm?

A

It is out of the governors range ?

3
Q

When the fuel selectors are in the ON position, how is fuel being fed from the tanks to the engines?

A

Left tank feeds Left engine

Right tank feeds Right engine

4
Q

When the fuel selector is on X-FEED, how it fuel being fed from the tanks to the engines?

A

That engine (L/R) will draw fuel from the opposite tank

5
Q

What are the limitations of our GFC 700 Autopilot? (9 total)

A

Cannot be used:

  1. Below 200’ AGL on Approaches
  2. DURING T/O or Landing
  3. Below 400’ AGL on T/O or Landing
  4. Below 1000’ AGL in Cruise
  5. With a fuel imbalance of 10 gals
  6. Below 80 KIAS (90 on IAPs)
  7. Above 190 KIAS
  8. For OEI Go-Arounds
6
Q

When will you hear the gear warning horn?

A
  1. Throttle below 14” in flight with gear UP
  2. Flaps extended more than 10 with gear UP
  3. Landing gear handle up when on the ground
7
Q

What does the Emergency Extension Knob do?

A
  • Equalizes/Releases the hydraulic pressure holding the gear up, and allows it to fall with gravity
8
Q

What kind of engines does the Seminole have?

A

Left: Lycoming O-360
Right: Lycoming LO-360

4 Cylinders
Horizontally Opposed - balance and reduced vibration
Air Cooled
Direct Drive

9
Q

How does the prop get in a high rpm, LOW pitch setting? (primary and secondary forces)

A

Oil is boosted to 275 PSI by a pump in the Governor

assisted by Aerodynamic Twisting

10
Q

How does the prop get in a low rpm, HIGH pitch setting? (primary and secondary forces)

A

Nitrogen charge is held between 33-41 PSI

assisted by Springs and Counterweights

11
Q

On what principle do Counterweights operate?

A

Newton’s 3rd law!

12
Q

How long does it take to Feather a prop?

A

~6 seconds

13
Q

How long does it take to Unfeather a prop?

A

8-12 seconds

14
Q

When prop is Feathered, what 2 annunciators will be visible?

A

LOW OIL

ALT INOP

15
Q

How are the propellers unfeathered?

A
  • Unfeathering Accumulator
  • Nitrogen and Oil are held at 275-300 psi in flight
  • The Governor blocks the passage of oil from the Accumulator to store it
16
Q

If the left fuel selector is on X-FEED, the left engine is getting fuel from the ____ tank

A

Right

17
Q

The HEATER runs off the ____ fuel selector

A

LEFT fuel selector

18
Q

Can you use X-FEED for takeoff and landings phases of flight?

A

NO

19
Q

What is unique about the Piper Seminole’s fuel vent designs?

A

Anti-icing design

20
Q

What are the fuel system’s capacities? (Total, usable, and unusable)

A
Total = 110 gal
Usable = 108 gal
Unusable = 2 gal
21
Q

What kind of electrical system do we have? (main battery, alternators, and overvoltage relay)

A

28v DC system
Main Battery = 24v (potential difference), 13.6 amps (measure of the current/strength)
Alternators = 28v, 80 amps
Overvoltage relay = 32v

22
Q

What are the 6 Electrical buses in the G1000?

A
(ENABLE)
Essential
Non-essential
Avionics
Battery
Lighting
Emergency
23
Q

Where are the Fresh Air Vents located in the Seminole?

A

Overhead!

24
Q

What is the proper way to shutdown the Seminole’s heater? (in-flight and on the ground)

A

In-Flight: Turn off heater, wait 15 seconds, then close air intake
Ground: Turn off heater AND switch to fan for 2 mins, OR until air is cold

25
Q

How long does retraction/extension of our landing gear take?

A

~6-7 seconds

26
Q

How does the landing gear operate? (fluid, pumps, psi)

A
  • Electrically powered, hydraulically operated (MIL-H-5606 hydraulic fluid)
  • The same reversible pump is used for both retraction and extension of the landing gear
  • Extension = 600 psi
  • Retraction = 1800 psi
27
Q

What 4 different types of Landing Gear switches does the Seminole have?

A
  1. Squat (2)
  2. Up Limit (3)
  3. Down Limit (3)
  4. Pressure
28
Q

What do the Squat Switches do?

A
  • Not engaged when on the ground
    Left = Prevents gear from retracting on the ground, blower motor
    Right = Disables lift detectors/stall horn on the ground, and mx hobbs
29
Q

What do the Up Limit Switches do?

A
  • Turn off gear unsafe annunciators

- Nose, Left and Right

30
Q

What do the Down Limit Switches do?

A
  • Engaged when on the ground, provide 3 Green indication, silence the gear warning horn/annunciator, and turn off the pump
  • Nose, Left and Right
31
Q

What does the Pressure Switch do?

A

Turns off the pump when pressure reaches 1800 psi with gear up

32
Q

What 3 things trigger the gear warning annunciator LIGHT?

A
  1. Up limit switches disengaged
  2. Down limit switches disengaged
  3. Gear warning horn is ON
33
Q

Define Vmc

A

FAR 23.149
The minimum calibrated airspeed at which, when the critical engine is suddenly inoperative, it is possible to maintain control of the a/c (straight flight path, same airspeed, with no more than 5 degrees of bank)

34
Q

Is Vmc displayed on the airspeed indicator?

A

Yes, with a Red Radial line!

35
Q

What is the difference between Vmc and Vmca?

A
Vmc = Whats published
Vmca = The actual speed given the varying conditions!
36
Q

Why do we practice Vmc Demo?

A

To be able to identify loss of control and recover

37
Q

What is the relationship between Vmc and Stall Speed?

A
  • DA up the vertical axis, Indicated Airspeed along the horizontal axis
  • Given the DA, your a/c can either Stall first, Yaw first, or have Vmc = Stall Speed
38
Q

In a critical Vmc situation, is it better to have the a/c stall first, or yaw first?

A
  • If it STALLS first, the warning horn could notify prior and you could take corrective action, but a stall could lead to yaw which could result in a spin
  • If it YAWS first, there isn’t really a warning, but you can reduce power and pitch down to regain control
39
Q

Which turning tendency is most critical according to the FAA? Explain it. When is it most pronounced?

A

P-Factor: Asymmetrical prop loading, creating YAW

  • The descending prop blade is taking a bigger “bite” than the ascending prop blade
  • Most pronounced at high AOAs!
40
Q

When is a spin most likely to occur in a multi-engine a/c?

A
  • One engine inoperative maneuvering

- Low airspeeds, high AOAs

41
Q

What is Accelerated Slip Stream?

A
  • By product of P-Factor

- Uneven amount of airflow accelerated back over the wings, causing the a/c to ROLL

42
Q

What is Spiraling Slip Stream? (draw a picture and think conventional twin)

A
  • Spiraling slip stream from one prop will hit the rudder, while the other does not!
43
Q

Why is the Left Engine the critical engine on conventional twins?

A

The operating right-hand engine will produce a more severe yaw towards the dead engine, thus making the failure of the left-hand engine critical.

44
Q

Which way do the props spin on a conventional twin? (As seen from the cockpit)
Which way do counter-rotating twin props usually spin?

A
  • Conventional props: Clockwise!

- Counter-rotating props: Left = clockwise, Right = counter-clockwise!

45
Q

What is Torque?

A
  • Newton’s 3rd Law

- Props are rotating one way, and the a/c wants to rotate in the opposite direction

46
Q

When the critical engine fails, WHY does Vmc increase and performance decreases?

A
  • LEFT TURNING TENDENCIES
47
Q

Maximum available t/o power (on the operative engine) ___ performance and ___ Vmca. Why?

A
  • Increases performance, Increases Vmca

- More power creates a greater yawing force

48
Q

Propellers in the Takeoff Position ___ performance and ___ Vmca. Why?

A
  • Increases performance, Increases Vmca

- Max RPM on the operative engine will increase yawing force, and windmilling prop will be producing a lot of drag

49
Q

Gear Retracted ___ performance and ___ Vmca. Why?

A
  • Increases performance, depends with Vmca
  • Retracted gear can increase airflow hitting the rudder (decreasing Vmca)
  • Retracted gear decreases stability (increasing Vmca)
50
Q

Most unfavorable CG ___ performance and ___ Vmca. Why?

A
  • An aft CG Increases performance, and increases Vmca
  • The arm between the CG and the rudder is shorter (decreasing rudder effectiveness), and the arm between the CG and the propeller is greater (creating greater yaw)
  • Aft CG means lower AOA in flight
51
Q

Takeoff flaps (0 flaps) ___ performance and ___ Vmca. Why?

A
  • Decrease performance, depends with Vmca

- 0 flaps provide no additional lift for 0 side slip, or deflection into the operative engine (increasing Vmca)

52
Q

What are 5 main parts of the Seminole’s Gear System?

A
  1. Reservoir (has 6 lines off it)
  2. Shuttle Valves (push things in and out)
  3. Mounting Base
  4. Pressure Switches (4 lines off it, N, R, L and emergency)
53
Q

What are the 7 main parts of the Seminole’s Fuel System?

A
  1. Tanks
  2. Selectors
  3. Filters
  4. Auxillary Fuel Pumps
  5. Engine Driven Fuel Pumps (primary route)/Primers (secondary route)
  6. Carbs
  7. Engines