What happened
On November 8, 1963, an Aero O/Y Douglas DC-3, registration OH-LCA, was performing a scheduled flight from Turku to Mariehamina. The aircraft had previously departed Helsinki with a stop in Turku. At the time of the accident, the aircraft was carrying a crew of three and 21 passengers, including two children, as well as one unauthorized individual in the cockpit.
As the aircraft approached Mariehamina airport, it was flying at an altitude of 2,000 feet using a QNH setting of 989 mb. While on the final approach to runway 20, the aircraft struck trees approximately 1,470 meters before the runway threshold and 50 meters before the 'S' locator station. The impact caused the aircraft to roll onto its back and immediately burst into flames. The fire destroyed most of the fuselage, leaving only the tail section intact.
Of the individuals on board, 21 people died due to the impact or the subsequent fire. The only survivors were the flight attendant and two male passengers.
The investigation
The investigation examined the aircraft's maintenance records, specifically focusing on the altimeters and the pitot-static system. Investigators also reviewed the weather conditions at the time of the approach, the functionality of the airport's lighting and radio equipment, and the crew's cockpit procedures. The inquiry also looked into the possibility of an error in the altimeter reading that may have occurred during the flight.