Personal injury accidents to the glider pilot while aerotowing are rare but the tug pilot can be killed if the glider gets too high and forces the tug into a vertical dive.
A previous educational campaign on safe aerotowing followed several fatal tug upset accidents between 1978 and 1985. The fatal accidents stopped, and the frequency of tug upset incidents diminished and remained at less than one per year until 2008. Since 2009, however, there has been an average of 3 upsets per year. In one of the 2012 incidents the tug pilot recovered 100ft above trees. In another incident, in 2013, the tug pilot recovered 40 ft from the ground. In 2014 another incident resulted in the tug impacting the ground at a 45° nose-down angle.
The BGA has published a leaflet on safe aerotowing with particular emphasis on avoiding tug upsets. Please collect a copy from your club or download a copy from this page. The guidance in the leaflet includes the following:
- If you are inexperienced, do not aerotow on a belly hook and do not aerotow in turbulent conditions.
- Maintain the correct vertical position of the tug in the canopy. Do not allow the glider to get too high.
- If you are too low behind the tug shortly after the tug take off, or at any other time, move back into position SLOWLY. Being lower than the tug is not dangerous. An upset can follow if you pull up quickly.
- Release immediately if the glider is going high and the tendency cannot be controlled, or you lose sight of the tug.
- Fly the glider! Leave any potentially distracting problems with instrumentation or ventilation until after release. Leave the undercarriage down.
- At release height, is it clear? Pull the release, visually ensure the rope has separated from the glider, and raise the nose slightly before making a turn.
The leaflet contains stills from the video simulations of tug upsets that can be found on this page.
Aerotow takeoff and climb performance can be affected by a number issues associated with the towing aircraft or glider – or a combination of both. There is some helpful guidance applicable to tug pilots and glider pilots here.