Incident Overview
On 6 June 2014, at approximately 08:23 UTC, an ultralight aircraft Tecnam P 92 Echo, registration OK-FUU 22, crashed during an aerotow of a glider LS 3 near the Křižanov airfield (LKKA). The towplane, operated by Aeroklub Křižanov, was on its third tow of the day. After takeoff from runway 32, the aircraft climbed normally for about 50 seconds before suddenly pitching down steeply. The glider pilot released or the towrope broke, but the towplane continued into the ground, impacting a wheat field and catching fire. The pilot of the towplane was killed.
Flight History
The pilot had performed two previous tows that morning without incident. The first tow with a T-59D Kestrel glider lasted about 9 minutes; the second with a DG-200 lasted about 8 minutes. After landing from the second tow at 08:19:22, the pilot taxied to the threshold of runway 32 for the third launch. At 08:22:26, he began the takeoff roll with the LS 3 glider. The aircraft lifted off after 28 seconds, approximately 250 meters before the end of the runway. Climbing at maximum power (RPM 5820) at an indicated airspeed of 111-125 km/h, the towplane reached an altitude of about 37 m AGL at 08:23:16.
At 08:23:18, recorded data showed a significant change: the vertical speed became negative (-5.1 m/s), the normal load factor dropped from 1.07 g to -0.57 g, and the longitudinal load factor changed to -0.50 g. The last recorded parameters at 08:23:21 showed an RPM of 3120 and load factors of -0.69 g (vertical) and 0.88 g (longitudinal). The aircraft then struck the ground at a steep nose-down attitude, approximately 632 meters from the threshold of runway 14.
Glider Pilot's Account
The glider pilot reported that the initial takeoff and climb were normal, with a tow speed of about 120 km/h. The glider flew straight behind the towplane without yawing. At an estimated height of 30-40 m AGL, he suddenly saw the towplane pitch down sharply, slightly to the right, and dive toward the ground. He attempted to release the towrope but felt a tug indicating it had broken before he could activate the release. The glider pilot then executed a left turn and was able to glide back to LKKA, landing on runway 14. He noted no radio communication or signal from the towplane pilot during the incident.
Aftermath
The towplane was destroyed by impact and subsequent fire. The pilot of the towplane died. The aircraft was equipped with an IGC flight recorder; data from that and the glider's recorder were used in the investigation. No injuries were reported for the glider pilot. The investigation was conducted by the Czech Institute for Air Accident Investigation (ÚZPLN) under EU regulations.