Narrative:

The event occurred after takeoff. The first part of my IFR clearance entailed 'radar vectors....' the first fix was on a 018 degree heading; approximately 30 degrees left turn from runway heading. While talking to tower; and after a normal takeoff; I was on initial climb out and at 400 ft AGL I began my 'after takeoff checklist'. Part of this list calls for 'yaw damper on.' this button on the autopilot console is right above the 'autopilot engage' button. I completed this list and was handed off to departure. After reporting in to departure; I noticed that the autopilot was engaged and in the 'roll mode.' this is the default mode for autopilot engagement. Apparently I inadvertently pushed the autopilot button instead of the yaw damper button. When the autopilot is engaged; if the wings are in a five degree or greater bank; the autopilot will continue a turn in the direction of the bank. Since I was unaware that the autopilot was engaged; the aircraft rolled approximately ten degrees left of course before I realized that the autopilot was engaged. After realizing the situation; I engaged the 'heading mode' which began a turn back to runway heading. At this time; the departure controller cleared me 'direct' to a fix. I then turned to a heading of 018 degrees. The controller then asked me if I had initiated my turn to the fix before being cleared to do so. Unable to describe the events noted above in a simple and concise way; I replied that I had initiated the turn early. I was not asked to call any authority on this event; and perhaps it was not a significant issue to departure; but I realize the importance of closely and accurately following the instructions as issued. I have reviewed the event from several points of view; and I believe that I understand the cause of the problem as well as corrective action to prevent its future occurrence. The cause of the event was an 'inadvertent' engagement of the autopilot during the 'after takeoff' checklist while in a slight left bank. The result of this action was a slow left bank and a course deviation of approximately ten degrees. This was then being corrected when the 'turn on course' clearance was received from departure. This deviation was not an intentional turn on course. It was directly caused by the events described above. In order to prevent the possibility of this recurring in the future; there are several steps that I have taken: 1) verify the result of all checklist items after performing any operation. In this case; verify the yaw damper annunciator 'on' before proceeding to the next item. 2) in VMC conditions; visually verify aircraft position relative to the airport after anything that requires 'eyes in cockpit' action. 3) always maintain a wings level attitude (within 5 degrees) on takeoff to avoid an engagement of the autopilot in 'bank' mode. (This may not be possible in a crosswind or turbulent conditions.) 4) on initial climb; always follow autopilot engagement by engagement of 'heading mode' to avoid any unintentional or unrecognized banks or turns initiated by the autopilot. I believe that these process improvements will prevent a future occurrence of this type of an event.

Related reports:

Google
 

Original NASA ASRS Text

Title: An EA50 pilot inadvertently engaged the Autopilot after takeoff instead of turning on the Yaw Dampener. A track deviation resulted because the autopilot engaged in a slight turn.

Narrative: The event occurred after takeoff. The first part of my IFR clearance entailed 'Radar Vectors....' The first fix was on a 018 degree heading; approximately 30 degrees left turn from runway heading. While talking to Tower; and after a normal takeoff; I was on initial climb out and at 400 FT AGL I began my 'After Takeoff Checklist'. Part of this list calls for 'Yaw Damper On.' This button on the autopilot console is right above the 'Autopilot Engage' button. I completed this list and was handed off to Departure. After reporting in to Departure; I noticed that the autopilot was engaged and in the 'Roll Mode.' This is the default mode for autopilot engagement. Apparently I inadvertently pushed the autopilot button instead of the Yaw Damper button. When the autopilot is engaged; if the wings are in a five degree or greater bank; the autopilot will continue a turn in the direction of the bank. Since I was unaware that the autopilot was engaged; the aircraft rolled approximately ten degrees left of course before I realized that the autopilot was engaged. After realizing the situation; I engaged the 'Heading Mode' which began a turn back to runway heading. At this time; the Departure Controller cleared me 'Direct' to a fix. I then turned to a heading of 018 degrees. The Controller then asked me if I had initiated my turn to the fix before being cleared to do so. Unable to describe the events noted above in a simple and concise way; I replied that I had initiated the turn early. I was not asked to call any authority on this event; and perhaps it was not a significant issue to departure; but I realize the importance of closely and accurately following the instructions as issued. I have reviewed the event from several points of view; and I believe that I understand the cause of the problem as well as corrective action to prevent its future occurrence. The cause of the event was an 'inadvertent' engagement of the autopilot during the 'after takeoff' checklist while in a slight left bank. The result of this action was a slow left bank and a course deviation of approximately ten degrees. This was then being corrected when the 'turn on course' clearance was received from Departure. This deviation was not an intentional turn on course. It was directly caused by the events described above. In order to prevent the possibility of this recurring in the future; there are several steps that I have taken: 1) Verify the result of all checklist items after performing any operation. In this case; verify the Yaw Damper annunciator 'ON' before proceeding to the next item. 2) In VMC conditions; visually verify aircraft position relative to the airport after anything that requires 'Eyes in Cockpit' action. 3) Always maintain a wings level attitude (within 5 degrees) on takeoff to avoid an engagement of the autopilot in 'Bank' mode. (This may not be possible in a crosswind or turbulent conditions.) 4) On Initial climb; always follow autopilot engagement by engagement of 'Heading Mode' to avoid any unintentional or unrecognized banks or turns initiated by the autopilot. I believe that these process improvements will prevent a future occurrence of this type of an event.

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.