EXTERNAL METHOD FOR EMPLOYING CDNU IN TRAINER SYSTEM

An external method for addressing the trainer-unique functions in a flight training system allows a Control Display Navigation Unit (CDNU), loaded with an actual Operational Flight Program (OFP), to function properly in a Flight Simulator environment of a trainer system without sacrificing the trainer-unique functions. A CDNU Trainer Interface Unit (CTIU) is defined to realize the external method. The CTIU is installed between the CDNU and the trainer system. The communication between the CDNU with an OFP and the trainer system is thus controlled by the CTIU. The trainer-unique functions are controlled externally by the CTIU, thus eliminating an OTP in the CDNU. The CTIU connects the CDNU and the trainer system. It communicates with both the trainer system and the CDNU/OFP using two sets of MIL-STD-1553B Buses. To the CDNU/OFP, it acts like the real navigation and communication systems. To the trainer system, it acts like a CDNU OTP. The CTIU will be able to address the trainer-unique functions with no modification to the OFP and CDNU hardware. The functions of the Operational Training Program (OTP) will be realized by the CTIU external to the CDNU/OFP. The CTIU activates OTP-equivalent capabilities upon receipt of OTP active commands from the trainer system.