Accident Overview
The accident occurred during the third leg of a dual instructional night cross-country flight. The airplane was in normal cruise flight at 4,500 feet mean sea level (msl) when it abruptly departed controlled flight and impacted a bog. The bog was approximately 15 to 20 feet deep with a thin layer of floating vegetation. The airplane came to rest inverted, and damage to the airframe was consistent with an inverted impact.
Flight Data and Sequence of Events
Data recovered from the airplane's flight display system indicated that, prior to the upset, the airplane was in stable flight on a 320-degree magnetic heading at 4,500 feet msl and approximately 160 knots true airspeed. The upset began with an abrupt departure from controlled flight: the airplane rolled approximately 20 degrees left wing down, yawed to the left about 30 degrees, and simultaneously pitched nose-down about 40 degrees. The aircraft then reversed and immediately entered a descending right roll for the duration of the flight. The airplane impacted the bog within 30 seconds of the upset.
Post-Accident Examination
Examination of the wreckage revealed that the left half of the horizontal stabilator was bent upward approximately 90 degrees, which was inconsistent with damage to the remainder of the airframe. This damage pattern was consistent with the initial left yaw and nose-down pitch recorded during the upset. Additionally, a depression and tear were observed on the upper wing skin near the left wing tip. Microscopic examination and DNA testing of material on the inside surface of the wing skin identified the remains of a Canada goose. The natural history of this species was consistent with the location, time, and date of the accident.