Airplane Damage Model

[Jasta 6]

Ya, i think i heard that standard procedure was that, if damaged, bomber crews were instructed to immediately drop their payload and return to base. And if i'm not mistaken the game mirrors this and tells you to *damage* as many bombers as possible to force them to turn around, instead of destroying them. So the grey icon means that its been damaged enough to force it to abort its mission. Can anybody confirm this?