Gerry, A quick check of the SDK. Quote from section from the [fltsim.n] section of the aircraft cfg file: atc_airline: The ATC system will use thw specified airline name with this aircraft. This is dependant on ATC recognizing the name. ATC will treat this aircraft as an airliner when used in conjunction with atc_flight_number. Atc_flight_number: The ATC will use this number as part of the aircrafts callsign. ATC will treat this aircraft as an airliner when used in conjunction with atc_airline. So my interpretation is leave atc_flight_number as unassigned. Either delete the line or delete anything after the equals sign:- atc_flight_number= Hope that helps Paul -----Original Message----- From: jhb-bounce@xxxxxxxxxxxxx [mailto:jhb-bounce@xxxxxxxxxxxxx] On Behalf Of Gerry Winskill Sent: 22 January 2008 08:57 To: jhb@xxxxxxxxxxxxx Subject: [jhb] FSX Traffic Query Does anyone know what allocates a particular aircraft in a traffic flightplan, to either the Airline Traffic or GA sliders? I thought it might be decided by whether its flight was VFR or IFR but it isn't. I've got an apron chock ablock with Harriers and Buccaneeres ay the Yeovilton I'm testing. Both respond to the GA slider. When I tried Hawks they were controlled by the Airline Traffic slider.... Gerry Winskill