In the current build, Peregrines can fire while landed, which means that they cannot be hit by other Peregrines or Fighters. I haven't tested this under a range of conditions, but this is definitely the case when Peregrines are guarding an idle unit.
They are extremely efficient in doing that and as well they can go in air way to fast. If this "feature" then they should probably land/take off longer or get other serious flaw. Or at least other fighters should ignore or even avoid them because currently all enemy fighters will just stuck around your landed fighters and die. PS: This one on bugtracker: PA#1132
It desperately needs to be a bug. Landed "hold position" fighters are ridiculously powerful, cheap, 'deployable' AA turrets. I don't think their stats are in-line with the power they get when doing this. Fighters should not be able to fire while in a state of "landed" or "taking off".
I think the whole mechanics of landing and fighters (not) shooting at landed air units is pretty buggy. Lots of ways to abuse.
