I REALLY don't understand what downed pilots you guys are refering to.
99.9% of players end sortie the instant they bail from the plane, and wouldn't wait for pick up even if they could hop back in a fresh plane, keep all their kills, and still have it count as one sortie.
Litterally, that would be the most useless function in the game, where the only time it could even potentially see use is in scenarios, if bailed pilots had to be picked up and brought back to their home field. however, even that would be impractical due to time limits.
I guarantee that you wouldn't pick up more than 1 pilot per day at the absolute max, and more likely would only pick up 1 pilot a week. And even thats being very optimistic.