Here's the NASA table for flight safety maximums (human): And these are absolutes, no safety net built in.
Time (min) +Gx -Gx +Gz -Gz
.01 (<1 sec) 35 28 18 8
.03 (2 sec) 28 22 14 7
.1 20 17 11 5
.3 15 12 9 4.5
1 11 9 7 3.3
3 9 8 6 2.5
10 6 5 4.5 2
30 4.5 4 3.5 1.8
... shows that people can withstand -7G for up to 2s. each neg G evasive movement will be in in the 0.1s range at most so the pilot isnt a limiting factor for this kind of evasion.
is the aircraft a limiting factor? not sure, but its easy to test - the film viewer shows the accelerometer readings, pushover real quick and see if the wings fall off, and at what G. I suspect this isnt an issue either - it doesnt take much -G to displace an aircraft 20yds off its heading, which if you're saddled up at d200 is enough to defeat the shot.
no E cost for this kind of maneuvering? rubbish. get to max level speed, note speed, do evasives, note speed again. 1000 perks says your speed has dropped.
unrealistic?
from the defender:
It would only be a matter of seconds now. I had lost airspeed, and even if I turned left or right, or dived, I would still, probably, not be able to escape him [saddled up 109]. But then I remembered sitting back in Eshott, listening to two RAF Battle of Britain pilots talking. Their words stuck in my memory: "The important thing is to do something. Make no movement gently, but be as violent as possible..."
from the attacker:
When he saw me behind he began to whip back and forth, left and right, as violently as he could. I followed, but it was hard to line him up for a shot. Finally, as we kept whipping back and forth, left and right, I began to shoot before he whipped and he had to fly through my fire.
Shaw spends several pages describing a "jinking" defense against saddled up opponents.
as for (relatively) sustained neg G evasion, its a standard ACM - the Hartmann Escape.
I see alot of comments about "neg G BS!", essentially they're just whines about not getting an easy kill.