What about in the case of buffs? Sure, the people near the flames would be affected, but others (those not near the fire) would not. That means that in a buff (and maybe some other planes) that the gunners could keep flying, pilots could keep flying.
Far this reason I like the 30 (or 20 or 15, etc) seconds and boom rule. That way everyone knows that a flaming bird is going to go away fairly quickly. You could even do it this way: 30 seconds to boom once fire starts; after 10 seconds, guns go inop; after 20 seconds the engines fail; 28, 29, BOOM!!!