This October 2007 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Aircraft: Piper Seminole. Location: Browerville, Minn. Injuries: 2 Fatal. Aircraft damage: Destroyed.

What reportedly happened: The accident flight was the last leg of a three-leg dual instructional night cross-country flight. The airplane was in cruise flight at 4,500 feet MSL when it abruptly departed controlled flight and hit a bog. The airplane came to rest inverted.

Data recovered from the flight display system indicated that the airplane was in stable flight on a 320° magnetic heading, at 4,500 feet MSL, and approximately 160 knots true airspeed when it abruptly departed from controlled flight. The airplane rolled approximately 20° left wing down, yawed to the left, and simultaneously pitched nose-down about 40°. It then reversed and immediately entered a descending, right roll and hit a bog. Investigators determined that the accident sequence lasted no longer than 30 seconds.

The post-accident examination noted that the left half of the horizontal stabilator was bent upward approximately 90°, inconsistent with the damage to the remainder of the airframe. In addition, 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 was identified as remains of a Canada goose. The area where the accident happened is goose habitat.

Probable cause: An in-flight collision with at least one Canada goose, and the resulting damage to the left stabilator that caused the airplane to become uncontrollable. Contributing to the accident was the night lighting condition, which precluded any possibility of the flight crew seeing the birds prior to impact.

For more information: NTSB.gov