Ya semp well its not about me getting shot down by a A20 never has been. I'm absolutely sure that's what you want to turn this thread into but it is not about that. So please stick to the subject if ya dint want f3 to be removed then say so in a intelligent way like -1. with comment on why it doesn't work for you. (idiot)
-1
F-3 mode is a fame concession made to balance the fact that, in bombers, there are multiple gunner positions. These gunners were afforded the use of an inter-ship intercom by which they could communicate with each other.
In Aces High, this is not the case. The coding allows only one gunner position to be filled, regardless of how many positions are available per particular plane and because of this, allows F3 mode in bomber type aircraft with multiple gunner positions to make up for the lack of multiple "eyes in the sky".
The Havoc is armed as follows:
4× fixed 0.303 in (7.7 mm) Browning machine guns in the nose
2× flexible 0.303 in (7.7 mm) Browning machine guns, mounted dorsally
1× flexible 0.303 in (7.7 mm) Vickers K machine gun, mounted ventrally
Planes such as the IL2, Bf 110 series, etc. only have one rear-facing gunner position, and therefore do not have F3 mode available. Even if one took a gunner in planes with only a tail-gunner position, the view is still only limited to that of a forward or aft view, unlike other bombers with different combinations of a dorsal, ventral, forward, aft, or port/starboard view.
This is why the Havoc has F3 view enabled and it is the reason it was removed from the IL-2. The biggest threat from the A-20 are the nose guns which, at .303 caliber and set at optimum convergence (meaning that when grouped in such a fashion the the edges of each round touch and do not overlap), the maximum diameter of an entry hole (considering the diameter of the hole as an inscribed circle into which the shot group can fit into) is .731" or < 3/4", per shot group landed which is smaller than the diameter of a quarter (.944").

Upon further speculation and review, if one got one's self into a position where one allowed one's self to get peppered by a sufficient number of less than quarter-sized holes to destroy or render one's aircraft non-airworthy, it is the fault of the one being shot at and not related to any flaw or faulty lines of code in the software.
Carry on.
