Flight History
The microlight pilot took off from Itxassou aerodrome to tow an Alexander Schleicher ASK21 glider (registered F-CITS) with two pilots on board. While skirting the slope below Artzamendi summit, the microlight encountered a flight of vultures and executed a sudden evasive maneuver by turning right and descending. The microlight then returned to a nose-up attitude and turned left. The glider pilot released the cable and turned in the opposite direction. The microlight’s left turn, facing the slope, continued and became more pronounced. The microlight collided with terrain during the turn and caught fire approximately 30 minutes after the collision. The glider turned around and landed at Itxassou aerodrome.
Examination of Site and Wreckage
The wreckage was found on the south-western slope of Mont Artzamendi, about 150 m below the ridge. It was completely destroyed by fire. The microlight was intact when it collided with the ground. Continuity of flight controls in roll and yaw was verified. The engine was jammed due to impact.
Aircraft Information
The microlight was a Comco Ikarus C42 C with an empty weight of 292.4 kg and a maximum allowable take-off weight of 472.5 kg, restricted to 400 kg when towing a glider over 400 kg. It had a towing hook located at the bottom and behind the tail fin. The flight manual specified use of an aeronautical-standard cable between 40 and 60 m, with a fuse pin if ultimate load exceeded 300 daN. The towing cable was slightly less than 50 m, continuous, and not equipped with a fuse pin.
The glider was an Alexander Schleicher ASK21 with an empty weight of about 360 kg and a maximum take-off weight of 600 kg; estimated mass was about 500 kg. It had a nose hook for towing.
Pilot Information
The 77-year-old microlight pilot held a microlight pilot certificate (issued December 1996) and a glider tow rating (August 2014). He also held a glider pilot licence and a Private Pilot Licence (Aeroplanes) with glider tow rating, and a valid Class 2 medical certificate. He had logged over 300 flight hours in microlights (10 in type in last three months, exclusively towing), over 600 hours in gliders, and over 700 hours in aeroplanes.
The glider pilot at the controls held a glider licence issued in 2010 and logged about 300 hours. The second glider pilot held a licence from April 1999 and logged about 400 hours.
Meteorological Information
Météo-France estimated conditions at the accident site: wind 10 kt from 220°, CAVOK, temperature 14 °C.
Statements
An onlooker heard the microlight’s engine, saw the glider slightly higher, then the microlight turned left with steep bank and collided with the mountain after less than 180° of turn. Many vultures were present. The glider pilots reported flying westward along the slope at about 700 m when three or four vultures appeared between tug and terrain. The microlight pilot executed a right-hand evasive bank (estimated 30°) and steep nose-down without announcement, then a pull-up. The cable slacked and tautened, pulling the microlight. The glider pilot saw the microlight return to level flight then turn sharply left; he released the cable and turned right.
Conclusions
The scenario indicates that while towing, the microlight pilot encountered vultures and instinctively performed an evasive maneuver without announcing it. The glider pilot, surprised, did not release the cable. Jolts on the cable, lateral separation, and possible high tow position made control difficult. The microlight banked left toward terrain; the glider pilot released the cable and turned away. The microlight’s turn continued, and due to small lateral margin, collision was unavoidable. Contributing factors included lack of announcement, non-release of cable by microlight pilot and late release by glider pilot, the glider being heavier than the microlight, and a shorter cable length. It could not be verified whether fuse pins would have helped. Difficulty regaining control after release may have contributed.