BAe 125 Series 800
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem
Aircraft
Departing EGE VMC on the GYPSUM 4 departure departing Runway 25; at 600 FT AGL autopilot was engaged with NAV selected. After an initial turn by the autopilot to the correct heading of 215 degrees; the autopilot then began a right turn direct Snow VOR. Due to crew confusion as to what the automation was doing and VMC with climb performance/terrain avoidance not an issue; immediate corrective action was not taken. As the aircraft crossed over Snow VOR; what appeared to be the GPS fix for the turn to KIRLE intersection appeared on the MFD. As the aircraft approached this fix; the fix began 'leap frogging' across the screen preventing intercept by the autopilot. Manual control was taken at this point and corrective vectors on course from Denver Center were followed. Terrain or weather was never an issue at any time. The remainder of the flight and subsequent legs were completed without further incident. The pilot not flying had experienced a similar episode of a fix 'leap frogging' with the Collins equipment in the simulator the week before. The information was given to the Hawker ACP on duty and forwarded to the appropriate personnel with additional information provided.
We were approaching the 322 radial off of DBL expecting it to begin the right turn toward KIRLE. The turn was depicted on the FMS and on the MFD. As we approached the intercept the aircraft continued straight through the course. Also at the same time it was showing on the MFD that the fix kept moving further in front of us. Best analogy would be a carrot in front of a horse. The fix was there it just kept cycling further in front of us. At about the same time I told the PF to select heading and turn toward KIRLE; he was also able to see the fix keep moving just in front of us. At first I thought that INHIBIT was selected instead of AUTO on the FMS. This was not the case. AUTO was selected. As quickly as we began a manual turn toward KIRLE ATC queried us about our turn and then gave us a 260 heading and we proceeded on a new ATC course.
HS-125-800XPC flight crew reported Collins FMS anomalies climbing out of EGE.