At about 40Kts, the aircraft will leave the ground and will be airborne. You should keep the nose low until a safe height is reached and the airspeed is between 55 and 59Kts, at which point, rotate into the climb (about 45 degrees angle).
The script attempts to emulate a real launch so if at any time the speed drops to around 55Kts, lower the nose back to the horizontal. This is a visual signal to the winch driver to increase the revs and doesn’t rely on the comms system working.
If the speed starts to rise above 60Kts, ease the stick back to reduce speed. Aim to keep the speed at between 55 and 60Kts
If the speed drops below 50Kts, pull off (release the cable) and initiate your “Launch Failure” eventualities NOTE. In real life – with 1200 metres of 4mm steel cable hanging from the airframe, the extra wing loading means the stall speed will increase to around 50Kts. It is not clear whether X-Plane takes the cable weight into account when calculating stall speeds. The above procedure should however be adhered to in the sim – especially if you intend to try gliding for real one day as your life may well depend on getting it right.
Likewise – if the speed increases above 70Kts – pull of and again carry out your “Launch Failure” eventualities. Some modern, heavy gliders like the DG600 are ok at 70Kts but with lighter wooden ships such as a K8, you risk serious damage to the airframe if you go much above 70Kts.
At the top of the launch as the glider gets closer to the apex, the cable will start to pull the nose of the glider down and the horizon will come into view. Lower the nose to below the horizontal and release the cable (in real life this will put some slack into the cable, releasing tension and ensure that the glider doesn’t “ping off” and pitch nose up – it allows you to release elegantly.