What happened
On August 14, 2008, an M.S. 880B Rallye Club aircraft, registration OH-SDZ, was performing a takeoff from runway 26L at Räyskälä aerodrome. The flight was part of a multi-leg journey, having previously stopped in Nummela and intending to proceed to Halli and then Kauhava.
During the takeoff roll, the aircraft accelerated slowly. Upon reaching an altitude of approximately 10 to 15 meters, the aircraft encountered severe, gusty winds. The aircraft was buffeted by these gusts and failed to climb further, eventually entering a stall and descending back to the ground. Upon impact, the nose gear collapsed, the propeller blades bent, and the aircraft slid approximately 20 meters along the ground. The left wing partially tore away, and the tail section struck the ground. There were no injuries to the pilot or the two passengers on board.
The investigation
The investigation examined the aircraft's weight, the prevailing meteorological conditions, and the takeoff performance. Investigators determined that the aircraft was loaded significantly above its maximum takeoff weight of 770 kg. Depending on the exact weight of the passengers, the takeoff mass was estimated to be between 796 kg and 810 kg, representing an excess of 26 to 40 kg.
Meteorological data from nearby stations indicated strong, gusty winds from the southwest (approximately 220 degrees). At the Hämeenlinna station, mean winds were 24 knots with gusts up to 40 knots. The investigation also noted that the proximity of the treeline near runway 26L created significant turbulence and potential downdrafts as the wind crossed the forest edge.
Findings
- The primary cause of the accident was the combination of taking off with an aircraft exceeding its maximum allowable takeoff mass and the highly challenging wind conditions.
- The wind was a strong, gusty crosswind from the left (approximately 40 degrees relative to the runway).
- The aircraft's weight exceeded the structural limit, which negatively impacted takeoff performance.
- Turbulence and potential downdrafts caused by the nearby forest edge contributed to the loss of altitude and subsequent stall.
- The aircraft was in good mechanical condition with no technical failures reported prior to the event.