Cessna 172, Carbretor

This is the carburetor of the Cessna 172.
By moving the throttle lever from the cockpit, The position of the throttle valve change and the amount of the air goes into cylinders change.

On the other side, the throttle valve is connected to the accelerator pump which give more fuel when the air increased.

Carburetor is located at the bottom of the engine. Air comes in from the inlet through the filter, then airbox in which the carburetor heat valve is located, then go up into carburetor and mixed with fuel there then divided into 4 cylinders. Why bottom of the engine? Because it would be very hard to see the front over cowling if the carburetor is located on the top of the engine.

Below the Pilot-Beechcraft Baron B55

This is Beechcraft Baron B55. The floor is removed.
The big white case is the gear box driven by electrical motor( the motor is in the blind spot). The motor turns the worm gear to turn the big gear in the gear box. Then the bell crank on the top of the box is rotated to move push-pull rod which are connected to the landing gear strut.

When the motor is inoperative, you still can move the landing gear down by turning the red hand crank manually. This s hard work for pilot. You will realize how great the motor is. Note, some airplane such as F-4-F Wild cat has manual retractable gear. Pilot must turn the hundle 29 times to move the gear up and down.

The motor on the upper left is for the wing flaps. It turn the flexible cable to move flaps up and down. There is only one motor for both right and left flap. Why? Imagine you each flaps have their own motor and one become inoperative, it causes the asymmetrical flap.