Induction and Engine Airflow Systems What method(s) is/are used to provide clean air to the engines of helicopters and turboprop airplanes that have particle (sand and ice) separators installed? a. Positive and negative charged areas to attract and/ or repel particulates out of the airflow. b. Air/moisture separators, and “washing” the air clean utilizing water droplets. c. Sharp airflow directional change to take advantage of inertia and/or centrifugal force, and filters or engine inlet screens.