CB SIFT CB E. only a glider. but this list is graven (or beaten) into the brain of every student pilot.
Controls - Full and Free.
Ballast - weight and balance correct
Straps - securely fastened
Instruments - working and set
Flaps (if fitted) - set for takeoff
Trim - set for airspeed in case of launch failure
Canopy - closed and locked
Brakes - airbrakes in this case, not wheelbrakes
Eventualities - your plan of what to do in case of launch failure
When you have completed this memorised check list, then you may accept the launch cable, whether airtow or winch. The club member on the wingtip will check that above and behind is clear to go. The signal, by radio or by arm for takeoff is given to the tug pilot or the winch driver. Then up you go!
For all that, I had to stop a launch when I was only a beginner holding the wingtip; the highly experienced chairman of the gliding club still had the gust locks on his wings...........the rule is that anyone may STOP a launch if you see danger.