What happened
During a daytime flight under visual flight rules, an experimental biplane collided with the frozen surface of a lake while performing a local area flight. The aircraft was owned, maintained, and raced by the pilot, who had accumulated more than 700 hours of flight time in this specific airplane.
The investigation
An examination of the wreckage showed no mechanical anomalies that would have prevented normal operation before the impact. However, investigators discovered a broken beer bottle inside the pilot's flight suit. Post-mortem testing revealed the pilot's chest blood ethanol level was 0.155 percent and his post-mortem urine ethanol level was 0.279 percent. These levels indicated the recent ingestion of substantial amounts of alcohol, sufficient to render a non-tolerant person nearly unconscious.
Findings
Investigators found that the pilot had a prior driver's license suspension ten months before the accident due to driving with a blood alcohol level exceeding 0.250. While the FAA was aware of the suspension, they had not reviewed the specific arrest details. Had the FAA reviewed the record, they would have identified that the pilot met the regulatory definition for substance dependence due to increased tolerance, which likely would have prevented the issuance of his medical certificate without thorough evaluation and treatment.