What should I do when rope breaks at 220-360 ft [75-120m] when there is not sufficient runway to land ahead and not sufficient altitude to make a return manuover and land with the wind direction?
Depends on the wind and the surrounding area. If there is enough headwind, you will be surprised how short your approach will be in a proper sideslip. Practise sideslipping at altitude, so you know what to do in an emergency! Otherwise, look around for an open field where to land; gliders are easily disassembled and carried back to the airport.
When the cable breaks, push the stick forward. Be prepared for dirt flying up and into your eyes if you push hard enough! Then stabilise at the minimum sink speed, release the remaining cable and look around for your options. There should be some:
- Land straight away if headwind plus sideslip allow for a steep descent.
- Fly straight a bit, then turn around 180° and land opposite to your direction at take-off. Do this only when there is no or almost no wind! 100m of altitude is plenty enough for this trick.
- Keep flying straight and land on an open field near the airport.
- Fly a triangular, shortened pattern and land in the regular direction.
If the airport is surrounded by forest or houses on all sides, try to land on the glider port - normally, the altitude bands required for the landing straight on, the 180° return landing and a landing from a proper pattern overlap enough so that there is never an altitude that would not allow to land on the airfield.
It depends very much on your field which is why (in the UK at least) you list Eventualities (usually cable breaks) as part of the CBSIFTCBE pre-flight checks.
Usually you have Low level - land ahead, higher level - part turn and cross field landing, higher again-turn and reciprocal landing and higher still-run a truncated circuit and land as normal.
My main field has crops or turf fields ahead depending on wind direction so I have a lot of scope for a forward landing, it is a wide field with two main strips and a short diagonal strip so a cross field landing is possible and it is a long field so a reciprocal landing is straightforward.
Your best bet is to ask advice on your specific field from the CFI.
when there is not sufficient runway to land ahead and not sufficient altitude to make a return manuover and land with the wind direction
If this is really case, I would not launch in such site. But since you have winch there I assume its fine - maybe its just your feeling?
~90m alt when cable was broken, with return option, with 10 m/s wind - downwind landing, and I ended up 25cm before a fence on the end of an airfield
10 m/s is a lot ( 20knts, 36 km/h), if you manage to do tailwind landing, it means you probably could land ahead as well...
Anyway, BGA has great sources about safe winch launch: https://members.gliding.co.uk/bga-safety-management/safe-winching/