Everyone should give the field guns a try.
Now that the Osti's view is less than useful, may I suggest getting in one of these instead of the ubiquitous wirbel when ground-based defense is in order? For the forseeable future, there will always be plenty of wobblies coming out of the VH, one might as well be different and get in a field gun before they are all taken out. I manned one awhile last night with good results, including one 5 kill sortie, in which NONE of the attackers were actually flying directly towards me. Hits included de-tailing an F6F flying overhead at 1.5k and credit for one kill and one assist on a formation of buffs that passed more or less overhead and were never closer than 2.5K, (and I'm far from being a gunnery god). That's REACH and power the wobbly can't touch. Don't believe what you hear, you CAN hit deflection shots with the 37mm, and unlike a wobbly, one ping means one kill. A wirbel won't usually be able to stop an accurate divebomber before he releases his egg, a 37mm boulder just might.
So give it a try, use Zazen's method, and just keep pumping plenty of rounds into the air at any target under 2.5K. You might be surprised how well you do.