FINAL REVIEW Flashcards
Why do we use a reduction gearbox for the engine?
-To reduce rotational speed of the propeller and prevents it from exceeding its designated speed at the tip of the prop.
Most common method to prevent carb icing?
-Pre- heat the air before entering the carburetor by either a heat muffler or engine compartment air. (Carb Heat)
What is the formula for work?
Work= Force * Distance Travelled
Why are laminated pole shoes used in magnetos?
To reduce eddy currents. Keeps magneto cool and boosts efficiency
What are the two forces that oppose each other in a CSU governor?
Speeder Spring Tension and Governor Fly Weights
Oil booster pump incorporated in the lower case of a governor of a CSU unit is necessary for?
-Move the propeller to fine pitch.
What is Torque?
-A twisting force that tends to cause rotation.
What component is used to prevent over housing
-Pressure valves and bootstrap
What does Wastegate control?
-Controls the amount of exhaust gas is passed through the turbine
Wastegate full open?
-Gases bypass engine
Wastegate full closed?
-Gases through engine
What is the approximate thermal efficiency of an internal combustion engine?
-30% heat energy into mechanical energy
What is Pre- Ignition?
-When the fuel/air mixture is already mixed causing the combustion to pre- ignite before actual ignition. This happens because of a hot spot in the cylinder.
What is Detonation?
-The uncontrollable explosion of fuel/air mixture. Engine knocking. Normally occurs due to using lower fuel grade.
What is the Compression Ratio?
Total Volume of Cylinder/ Combustion Chamber Volume
What are the 3 types of Carburetor Icing?
- Fuel Evaporation Ice
- Throttle Ice
- Impact Ice
What is Upper Deck Pressure?
-Pressure after blower but before the throttle
What is Maximum Upper Deck Pressure?
-Absolute pressure controller functions to limit
What is sensed by the APC, Rate of Change and Pressure Ratio Controller through the oil flow of the wastegate?
-Upper Deck Pressure
Pressure Controller setting is how many times the ambient pressure?
2.2
What does the Rate of Change controller function to?
-Limits the UPD from 2.0-6.5 Hg to reduce turbine acceleration over boosts
What is Bernoulli’s Principle?
-When Velocity increases, Pressure decreases
What is the function of the main metering system?
-To supply fuel flow at all conditions above idle
Where is the fuel nozzle in the pressure carb?
-Downstream of the venture therefore it is less susceptible to icing
What are the two adjustments on the Pressure Carb?
- Idle Mixture
- Idle Speed
What type of coils do magnetos have?
-Primary and Secondary
What is the Mag Speed?
-100-200 RPM
What does impulse coupling do when it increases the rotational speed of the magneto?
-Retards the spark to TDC to prevent kick back
What type of electrode would be least prone to lead deposits?
-Fine wire
What type of Oil Pumps do Lycoming Engines use?
-Gear type (constant displacement pumps)
What does an Oil Spec of 10W30 mean?
- 10 = Less viscosity when oil is cold.
- W = Winter/Cold weather conditions
- 30 = High viscosity when oil is hot.
Oil with no additive used for engine brake in is?
-Mineral oils
Pour point is?
the lowest temperature at which a substance will flow under given conditions.
What kind of sump does a radial engine have?
-Dry Sump
What is the main factor contributing to Carb Icing?
-Humidity
What is the most common way to prevent Carb Icing?
-Pre- heat the air before it enters the carburetor by a heat muffler or engine compartment air. (Carb Heat)
What happens when Carburetor powers down and Carburetor heat goes up?
-Rich Mixture
A plain connecting rod is used in what type of engines?
-Opposed or Inline
Radial Engines have what type of connecting rods?
-Master Rod
In addition to the pressure pump, the dry sump system has what kind of pump?
-Scavenge Pump
