You can't join straight in as NCO pilot.
Minimum rank for starting the course is Cpl with recommendations for Sgt.
Chaps who start the course tend to have at least 5 years experience under their belt. Thats usually the minimum. Par is about 9 years.
That's interesting. On my Shawbury course we had 2 acting Cpls who were getting substantive on completion of Wallop (might have been completion of EGOS). Hardly think that either of them had Sgt recommends.