Fatal Letov LK-2M Sluka Accident at North Coates Airfield (G-MZOT)

Accident Overview and Flight History On 6 August 2006, a Letov LK-2M Sluka microlight aircraft, registration G-MZOT, was destroyed in a fatal accident at North Coates Airfield in Lincolnshire. The aircraft, manufactured in 1999 and powered by a single Rotax 447 1-V piston engine, was operating a private flight from Bucknall to North Coates. The 62-year-old pilot, who held a Private Pilot’s Licence with 450 total hours of experience, was the sole occupant and was fatally injured in the impact. The pilot had departed Bucknall at 1445 hrs, flying in the company of a Thruster microlight. The Thruster arrived at North Coates ahead of the Sluka and landed on grass Runway 05 at approximately 1520 hrs. The pilot had not reported any issues with the aircraft or flying conditions prior to the flight. ## Emergency Approach and Impact As the Sluka approached the airfield boundary, the pilot transmitted a radio call indicating a partial elevator failure and a request for an emergency landing. The aircraft crossed the threshold of Runway 05 at approximately 500 feet above ground level. The pilot initiated a descending right-hand orbit, stating he was too high, and rolled out on the centerline at about 200 feet. He subsequently reported struggling to obtain full elevator trim and being unable to move the control stick forward. Witnesses observed the aircraft experience a sudden lift or climb before the nose rapidly pitched down. The aircraft impacted the ground in a near-vertical attitude approximately 100 meters from the runway threshold, coming to rest inverted with the engine detached. ## Investigation Findings and Probable Cause The investigation determined that a nut and bolt attaching the tailplane bracing wires to the vertical fin had come undone, resulting in a structural failure of the tailplane. The Sluka’s tail surfaces are fabric-covered and tubular, with the horizontal stabilizer comprising left and right tailplanes pin-jointed to the boom. Structural rigidity is provided by upper and lower bracing wires. The upper wires are secured by a bolt and a stiff nut, while the lower wires use a castellated nut and split pin to allow for folding. Examination of the wreckage revealed that the right tailplane was significantly drooped and its elevator was disconnected. The missing stiff nut allowed the tangs and associated wires to detach from the fin. Microscopic examination of the bolt threads and tang holes showed no evidence of distress from excessive load or incorrect hardware. The pilot died from multiple injuries, and no evidence of disease, alcohol, or drugs was found.