Aircraft Systems

Question 1

What is the name reciprocating engine derived from?

Answer 1

Most small aircraft are designed with reciprocating engines. The name is derived from the back-and-forth, or reciprocating, movement of the pistons that produces mechanical energy.

Question 2

What is the main difference between spark ignition and compression ignition?

Answer 2

Spark ignition engines use a spark plug to ignite a pre-mixed fuel-air mixture. (Fuel-air mixture is the ratio of the “weight” of fuel to the “weight” of air in the mixture to be burned.) A compression ignition engine first compresses the air in the cylinder, raising its temperature to a degree necessary for automatic ignition when fuel is injected into the cylinder.

Question 3

On a propeller, what part has the highest pitch and which has the lowest pitch.

Answer 3

Highest pitch is at the hub
Smallest pitch is at the tip

Question 4

Fixed pitch propellers operate best at what point?

Answer 4

fixed-pitch propeller achieves the best efficiency only at a given combination of airspeed and rpm, the pitch setting is ideal for neither cruise nor climb. Thus, the aircraft suffers a bit in each performance category. The fixed-pitch propeller is used when low weight, simplicity, and low cost are needed.

Question 5

How many types of fixed pitch propellers are there?

Answer 5

2 types

Climb
Cruise

Question 6

In a fixed-pitch propeller, what is the tachometer?

Answer 6

In a fixed-pitch propeller, the tachometer is the indicator of engine power.

Question 7

What is a tachometer?

Answer 7

A tachometer is calibrated in hundreds of rpm and gives a direct indication of the engine and propeller rpm.

Question 8

When changing rpm or manifold pressure, what are three ways to minimize over stressing the engine?

Answer 8

1. When power settings are decreased, reduce manifold pressure before reducing rpm.
   (If rpm is reduced before manifold pressure, manifold pressure automatically increases)
2. When power settings are increased, increase rpm, then manifold pressure.
3. To prevent damage to radial engines, minimize operating time at maximum rpm and manifold pressure, and avoid operation at maximum rpm and low manifold pressure.

Question 9

Whats a good tip about glide speed in a variable pitch propeller?

Answer 9

The operators of aircraft with variable pitch propellers should be aware that in certain instances of propeller overspeed, the airspeed necessary to maintain level flight may be different than the speed associated with engine-out best glide speed.

Question 10

What two induction systems are commonly used in small aircraft engines?

Answer 10

The carburetor system & the fuel injection system