Pest Control Aircraft Pilot Practice Test

What characterizes the spray pattern due to propwash displacement?

1. A uniform distribution across the swath

2. A heavier spray pattern on the right half of the swath

3. A heavier spray pattern on the left half of the swath

4. A lighter spray coverage across the middle of the swath

The correct answer is: A heavier spray pattern on the left half of the swath

The spray pattern characterized by propwash displacement results in a heavier spray pattern on the left half of the swath. This phenomenon occurs due to the direction of the propeller's rotation and the associated airflow that is created behind the aircraft. As the propwash moves air downward and outward, it tends to push the spray to one side. In many aircraft, the rotation of the propeller creates uneven airflow, which affects how the material is distributed as it is released from the spray nozzles. Specifically, this can lead to increased deposition on the left side of the swath when the pilot is flying a standard left-hand turn, commonly used in agricultural aerial applications. Understanding this characteristic is crucial for pilots to ensure effective and uniform pest control application across the intended target area. Adjustments in flight patterns or spray adjustments may be necessary to account for this uneven distribution and maximize treatment efficacy.