Accident to the BRM Aero Bristell B23 registered OE-AMK on 09/05/2024 at Chambery - Challes-les-Eaux

When the pilot of the aeroplane took off from paved runway 32, a winch launch was in progress on the parallel grass runway. The simultaneous use of the two runways is prohibited on the aerodrome.

The investigation was not able to precisely determine the sequence of events and in particular, whether the pilot of the aeroplane entered the runway after the winch operator had announced the start of a winch launch. The latter indicated that he had not detected the presence of the aeroplane as it taxied to line up at the holding point although he carried out the visual scan specified by the internal procedures notably designed to check that there is no aircraft on the runway before
starting the winch launch. While the aeroplane was taxing from the holding point, the runway supervisor of the gliding club warned the pilot over the frequency of the presence of a glider on final for the paved runway.  

The glider carrying out a winch take-off left the ground a few seconds after the aeroplane’s power was increased. At this point, the aeroplane and the glider were at a lateral distance of 85 m from each other. For an unexplained reason, the pilot of the aeroplane deviated to the RH side during the climb and the propeller collided with the winch cable.