"Is it random selection, or based on assessment scores? Or are you asked to give your preferred Aircraft type" - None of the above I suspect. Professional assesment of capability across the board will feature highly in selecting and grading modern airframe directional operatives. Gone are the days that a bloke with two wooden legs can bludgeon his way in to first line fighters. There's definitely a major external influence to selection these days IMHOP.
Smudge