ottoramsaig wrote on May 3^rd, 2011 at 2:44pm:

Is there a way to change FSX call signs?  For example on the C 130 ATC refers to you as SAF.  I would like to change it to something a little more realistic. My B 727 is Ok with Pan AM 001 though I would like to change that also.

Hi ottoramsaig,

I think you must try to change the call sign at:

C:\Program Files (x86) > Microsoft Games > Microsoft Flight Simulator X > SimObjects > Airplanes > CS_C130 > aircraft.cfg

.................................

[fltsim.5]
title=CS C130X 5
sim=C130
model=g
panel=g
sound=
texture=swe
kb_checklists=
kb_reference=
atc_id=SAF
atc_airline=Flygvapnet or Air Force (It was SAF)
atc_flight_number=
ui_manufacturer=Lockheed
ui_type="C-130E"
ui_variation="Swedish AF"
ui_typerole="Multi-Engine TurboProp"
ui_createdby="Captain Sim"
description="'C-130 X-perience' Pro Pack v.1.3\n(c) 2008 Captain Sim www.captainsim.com"
flg="Sweden AF"

................................

Check if the new call sign exists at airlines.cfg. If not, add it.

Further readings: http://en.wikipedia.org/wiki/Airline_codes

Best regards,

Pinatubo.