Narrative:

Conducted pre-flight and pre-takeoff checklist. Item to check door latch is listed and verified twice and confirmed by passenger. Just after rotation; the pilots' entry door opened. Stabilized airspeed and climb; then notified tower of situation. Tower cleared left traffic to return to runway. Proceeded upwind; crosswind and downwind to set up approach to land. On downwind leg door failed and liberated from aircraft and was lost in the swamp/lake area south of the airport. Landed without incident. Called tower later to let them know the door was not lost on the airport operations area. Search for door on ground was unsuccessful.

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Original NASA ASRS Text

Title: Zenair pilot reports pilot entry door opening just after rotation. On downwind during return to the airport the leg door departs the aircraft. A normal landing ensues.

Narrative: Conducted pre-flight and pre-takeoff checklist. Item to check door latch is listed and verified twice and confirmed by passenger. Just after rotation; the pilots' entry door opened. Stabilized airspeed and climb; then notified tower of situation. Tower cleared left traffic to return to runway. Proceeded upwind; crosswind and downwind to set up approach to land. On downwind leg door failed and liberated from aircraft and was lost in the swamp/lake area south of the airport. Landed without incident. Called tower later to let them know the door was not lost on the airport operations area. Search for door on ground was unsuccessful.

Data retrieved from NASA's ASRS site 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.