An emulator, which is a computer program, for simulating 32 bit ARINC-429 data output by an Inertial Navigation System on board a P-3 aircraft. The value for each word output by the emulator is adjustable by user. The user adjusts each value by using the computer's mouse to engage slider controls located on a computer applications window. ARINC-429 data which the user adjusts includes aircraft latitude, longitude and altitude data as well as pitch and roll data for the aircraft, and time and distance to a destination by the aircraft.