# prevent collisions between aircraft; # prevent collisions between aircraft on the maneuvering area and obstructions on that area; note that this objective does not include the apron and ATS in general is not intended to prevent collision with terrain. # expedite and maintain an orderly flow of air traffic; # provide advice and information useful for the safe and efficient conduct of flights; # notify appropriate organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required.