What must a pilot determine before running a pattern test for spray application?

Before conducting a pattern test for spray application, it is essential for the pilot to determine the spraying pressure and volume. This is crucial because the pressure governs the atomization of the pesticide, influencing droplet size, distribution, and coverage. Proper calibration ensures that the desired amount of pesticide is applied uniformly across the target area, which is vital for both effectiveness and environmental safety.

Factors like flight route, number of applications needed, and weather patterns are indeed important considerations in aerial pesticide application. However, they do not directly relate to the immediate concerns of how the spray is deployed during the test. The pressure and volume set the foundation for how the application will be executed, making it the most critical factor when preparing for a precise and effective aerial spray operation.