87.319—Scope of service.
         Aviation support stations are used for the following types of operations:
    
    
    
    
        
        (c) 
         Coordination of activities between free balloons or lighter-than-air aircraft and ground stations;
    
    
        
        (d) 
         Coordination between aircraft and aviation service organizations located on an airport concerning the safe and efficient portal-to-portal transit of the aircraft, such as the types of fuel and ground services available; and