Investigation Summary
The flight departed Kronoby 16 minutes behind schedule. Despite the delay, the crew requested and received permission for free flying altitude. This allowed the flight to operate at any altitude above the minimum flight altitude for the Kronoby to Vaasa route, which was 1,500 feet (460 meters). However, for the final 40 kilometers of the journey, the pilots disregarded these regulations and flew below 330 feet (100 meters). As they approached the Seppa non-directional beacon, the aircraft descended even further to below 160 feet. During a sudden left turn, the aircraft's speed dropped and airflow was disrupted, leading to a stall. Although the crew applied full throttle in an attempt to recover, the DC-3 entered a steep 70-degree left bank and spun into the woods. Eyewitnesses reported seeing the landing lights turn on just moments before impact. The resulting fire was so intense that first responders could not approach the wreckage for ten minutes.
Final Conclusions
The Accident Investigation Board (AIB) concluded the primary cause was pilot error during a low-altitude turn, aggravated by the crew's physical and mental state. Autopsies revealed Captain Lars Hattinen had a blood alcohol content (BAC) of 0.20% and First Officer Veikko Halme had a BAC of 0.156%. The investigation established that between 21:50 and 02:00 the previous night, the pilots and a third individual had consumed sixteen bottles of beer, seven gin grogs, and 900 grams of cognac. The board found no evidence of technical failure, icing, or pre-impact explosion, though they noted the possibility that a passenger may have been present in the cockpit at the time of the crash.
Photographic Evidence (1)
Video Analysis
AY311, Koivulahden lento-onnettomuus - Flygolyckan i Kvevlax — A detailed look at the Kvevlax air disaster, the deadliest accident in Finnish aviation history, caused by pilot intoxication and low-altitude maneuvering.
If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
Non-Directional Beacon (NDB)
The crew was navigating toward the Seppä NDB, a radio transmitter used for aviation navigation, shortly before the loss of control.
Landing Lights
Eyewitnesses observed the crew activating the landing lights immediately before the impact, suggesting a last-second attempt to identify their surroundings.
Interesting Facts
- 01This remains the deadliest aviation accident to ever occur in Finland.
- 02The pilots had consumed 900g of cognac, 7 gin grogs, and 16 beers just hours before the flight.
- 03The aircraft was flying at an altitude of less than 100 meters for the final 40 kilometers of the flight.
- 04The investigation found no evidence of technical malfunction or airframe icing.
- 05The crash occurred in a steep 70-degree turn.
Safety Actions & Advisories
Intoxication Regulations Reinforcement
The investigation highlighted the flagrant violation of ICAO treaties and personal employment contracts regarding pilot sobriety, leading to stricter oversight of crew fitness for duty.