first you need to be a competition glider pilot.
A recent article in the British Sailplane & Gliding magazine was an interview with John Allison the former Commander in Chief of RAF Strike Command (and glider pilot). In the article he says:
"Based on my background as a fighter pilot and my understanding of the qualities that you need to be a good competition glider pilot, many of these qualities are the same as those needed by frontline aircrew in the RAF.
The ability to think lucidly under pressure while operating in a slightly uncomfortable environment.
The ability to make on-going tactical decisions over a period of time without fatigue or loosing concentration.
The strength of character to manage risk successfully.
The ability to overcome personal fear.
The willingness, at times, to put it on the edge to achieve success.
The ability to think laterally.
Gliding is quite a cerebral activity. Anyone who could be a successful competition glider pilot has in my opinion bucketloads of aircrew qualities as I recognize them in a military context."