What is the propeller diameter?

What is the propeller diameter?

• A. 5 ft 7 in
• B. 5 ft 9 in
• C. 6 ft 0 in
• D. 5 ft 11 in

Answer: (B)

Propeller diameter is the distance from tip to tip of the blade circle when the prop is stationary. It determines the disc area available to accelerate air and thus affects thrust, efficiency, and clearance with the airframe. For the DA20-C1 setup in this context, the standard fixed-pitch two-blade propeller is specified with a diameter of 5 ft 9 in (69 inches). This size fits the engine and airframe geometry to provide the proper balance of thrust and ground/airframe clearance. If the diameter were smaller, thrust and efficiency would drop; if it were larger, there could be clearance issues or interference with structure. So the correct diameter is 5 ft 9 in.

Propeller diameter is the distance from tip to tip of the blade circle when the prop is stationary. It determines the disc area available to accelerate air and thus affects thrust, efficiency, and clearance with the airframe.

For the DA20-C1 setup in this context, the standard fixed-pitch two-blade propeller is specified with a diameter of 5 ft 9 in (69 inches). This size fits the engine and airframe geometry to provide the proper balance of thrust and ground/airframe clearance. If the diameter were smaller, thrust and efficiency would drop; if it were larger, there could be clearance issues or interference with structure.

So the correct diameter is 5 ft 9 in.