EMB ERJ 145 ER/LR
Flight Crew Commercial
Communication Breakdown; Distraction
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Aircraft; Human Factors; Procedure
During climb through FL200 we noticed the aircraft started to deviate off course to the right. We are unaware of why; but the FMS had entered a hold. The Captain had been changing some of the INIT Data because ATC had changed our final cruising altitude. However; we are both unaware of how that could have resulted in a hold being entered; since it is fairly difficult to enter a hold without knowing it. We were approximately 45 degrees off our course when I switched to heading mode and start to turn back toward our course. The Captain advised ATC of an issue with our autopilot and we were given a heading of 180. After getting the FMS out of the hold; we asked for direct and were given heading 190; direct when able. No further incidents occurred during the flight.Threats were a change in final cruising altitude that resulted in a change in the INIT data. There were no errors that we were aware of. The undesired aircraft state was the course deviation of 45 degrees. I should have been more carefully monitoring the captain entering data in the FMS; we are unaware if that was actually the cause of the deviation; however the FMS is where something was improperly entered and while I am usually paying close attention; it's always possible to miss something.
Not sure why it turned but communication between pilot to pilot regarding the programming of the FMS is key.
An EMB-145 entered holding autonomously while climbing to the revised cruise altitude after the Captain entered INIT Data to reflect the new revised altitude assignment.