Your eyes have a fantastic ability to look in a direction your head is not pointing. I can see more than 180° behind me. I'd say about 200°-210° in my case. I agree with rollnloop, the G forces would add another variable. Maybe this would get too gamey but I could see a system where if your harness is in the tight position it would limit your head movement and you'd be able to handle more Gs. If it was loosened, better movement less Gs.
If pilots couldn't see behind them what would be the point of a bubble canopy?
Armor piercing incendiary. Remove rubber bands from the control linkages. AI that doesn't constantly switch between max throttle and no throttle to stay in formation. Less fade of the gunsight reticle when head position is off center.
