What happened
The accident occurred during the third leg of a three-leg dual instructional night cross-country flight. The Cessna 172 was established in normal cruise flight at 4,500 feet mean sea level when it abruptly departed controlled flight and impacted a bog. The bog, which contained a thin layer of floating vegetation, was approximately 15 to 20 feet deep. Upon impact, the aircraft came to rest inverted. Data recovered from the flight display system showed the aircraft was in stable flight on a 320-degree magnetic heading at 4,500 feet mean sea level and approximately 160 knots true airspeed prior to the upset. During the event, the aircraft rolled approximately 20 degrees left wing down, yawed left about 30 degrees, and pitched nose-down about 40 degrees. The aircraft then reversed into a descending, right roll and impacted the bog within 30 seconds of the initial upset.
The investigation
Post-accident examination of the airframe revealed that the left half of the horizontal stabilator was bent upward approximately 90 degrees. This specific damage was inconsistent with the rest of the airframe damage but was consistent with the initial left yaw and nose-down pitch recorded by the flight display. Additionally, investigators found a depression and tear on the upper wing skin near the left wing tip. Microscopic examination and DNA testing of material found inside the wing skin identified the remains of a Canada goose. The presence of this species was consistent with the location, time, and date of the accident.