Beechjet 400
Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem
Aircraft; Human Factors
We departed Runway 27 at SAN. Our departure required us to proceed to JETTI Intersection and then continue on the departure. I was the non-flying pilot and noticed we were making a slight right turn taking us off course and I so advised the flying pilot. We then realized our command bars were giving us different indications. At this time the Controller asked what heading we were on. I replied that we were on a 305 heading. She gave us a 275 heading and told us to go direct PGY VOR. By this time we had already transferred the autopilot back to the left side and determined the right side was giving us erroneous information. We had been cleared to FL410 but upon reaching FL270 we let the new Controller know we were having issues with one of our navigation systems and requested FL290 until we determined we were legal to enter RVSM airspace. We later notified the Controller we were able to continue our climb. Either that Controller or the next advised us to call TRACON and told us it was for a deviation. The rest of the flight was uneventful and later on into the flight the systems seemed to be working.In the departure phase of this flight; everything was happening very quickly. Trying to determine the faulty side and making the proper adjustment to correct the deviation took some time. As soon as we noticed the erroneous indications of the instruments; we should have asked for a heading and then worked on finding a solution to our situation.
I began following the bars and glanced at the MFD to verify the turn. I noticed that the aircraft was deviating off the depicted track. I also noticed that wind vector indicated a 35 KT right quartering headwind. This led me to believe that the command bars were correcting for the wind. I now believe that it was an erroneous reading.
When the pilot flying's FMS provided erroneous guidance during the BE-400's departure from SAN; the flight crew switched roles and utilized the Captain's side avionics to complete their journey. ATC suggested the possibility of a deviation during their departure but none had been issued at the time of their submission.