Narrative:

After takeoff on runway 8R on the cokem 4 departure I selected speed mode and nav mode and at 600 ft the auto pilot was turned on. FMS2 was armed in the FMA. The autopilot was also active. While I was running the after takeoff checklist we received a master caution autopilot pitch trim followed by a master caution autopilot nd trim message. We were trying to determine what may have been causing these messages because all the trims were in the green. I was getting the QRH and turning to the automation section and my first officer turned off the autopilot. The aircraft pitched up abruptly. My first officer then re-trimmed the aircraft. When I found the pages I noticed that we were right of course. I looked to see what the flight director was showing. It showed wings level and the FMS2 were active in the FMA but we were still right of course. Hrshl was active as the next waypoint. I told my first officer to turn towards hrshl. At that point atl departure asked if we were navigating to hrshl. I told them yes we were turning and we had a problem. Then they gave a heading of 360. We turned left to heading 360. We now ran the QRH and then reselected the auto pilot on. [We] then received a master caution ap trim lwd message. Again ran the QRH and then reselected the auto pilot on. Then it worked normally. This all happened in less than 2 minutes ATC then asked us to call when we landed due to a possible loss of separation. The threats were the auto pilot caution messages just about the time we should have been turning towards hrshl. The errors were the FMS and auto pilot not locking on to the desired flight path and us not catching it because we were distracted by the caution messages. I have to disagree with the auto pilot on procedure at 600 ft for RNAV departures. I think gives us a false sense of security. I think by hand flying your paying closer attention to what the aircraft is suppose to be doing. You know coming out of atl on a RNAV departures your going to turn shortly after takeoff.

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Original NASA ASRS Text

Title: CRJ700 flight crew experiences a Master Caution Autopilot Pitch Trim followed by a Master Caution Autopilot ND Trim message shortly after engaging the autopilot at 600 FT AGL. When the First Officer disengages the autopilot the aircraft pitches up aggressively and a track deviation from the RNAV procedure occurs; resulting in loss of separation.

Narrative: After takeoff on Runway 8R on the Cokem 4 departure I selected Speed Mode and Nav Mode and at 600 FT the auto pilot was turned on. FMS2 was armed in the FMA. The autopilot was also active. While I was running the after takeoff checklist we received a Master Caution Autopilot Pitch Trim followed by a Master Caution Autopilot ND Trim message. We were trying to determine what may have been causing these messages because all the trims were in the green. I was getting the QRH and turning to the automation section and my First Officer turned off the autopilot. The aircraft pitched up abruptly. My First Officer then re-trimmed the aircraft. When I found the pages I noticed that we were right of course. I looked to see what the flight director was showing. It showed wings level and the FMS2 were active in the FMA but we were still right of course. HRSHL was active as the next waypoint. I told my First Officer to turn towards HRSHL. At that point ATL Departure asked if we were navigating to HRSHL. I told them yes we were turning and we had a problem. Then they gave a heading of 360. We turned left to heading 360. We now ran the QRH and then reselected the auto pilot on. [We] then received a Master Caution AP Trim LWD message. Again ran the QRH and then reselected the auto pilot on. Then it worked normally. This all happened in less than 2 minutes ATC then asked us to call when we landed due to a possible loss of separation. The threats were the auto pilot caution messages just about the time we should have been turning towards HRSHL. The errors were the FMS and auto pilot not locking on to the desired flight path and us not catching it because we were distracted by the caution messages. I have to disagree with the auto pilot on procedure at 600 FT for RNAV departures. I think gives us a false sense of security. I think by hand flying your paying closer attention to what the aircraft is suppose to be doing. You know coming out of ATL on a RNAV departures your going to turn shortly after takeoff.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.