I think the 50% failure rate is a mixture of both of those, at a guess I would say more failures come during line training. I think there is a lot of pressure on the academy to get people through the ground part of training. The Saudi line instructors however are not going to put anybody who they are not happy with in front of GACA or up for the company check. Fleets, well I have heard of failures on all fleets.
You can fairly accurately say that 50% of people who start today will not be here in 1 years time.