Who said that the Yak3 is a flying tank?
With a little bit of dedication and a store of ammunition, even a mosquito can bring down a tiny 2 ton plane with barely any armor.
In the following example I was firing the 4*20mm ONLY, so all the hit sprites are from the hispanos.
1st volley, hits to cockpit, back and tail:
WTF? fuel leak from right wing? OK shoot some more!
2nd volley, engine cowling:
3rd volley, cockpit, back, left wing-root... Russian Christmas tree:
Only visible result is oil leak and a fuel leak from the left as well.
4th, try more hits to the left wing:
continued volley, maybe the wingtip is weaker? no...
Lets blast the F out of the tail!
Yey! that took off one stab and its elevator...
More to the left wing:
More to the right to even things up:
AHA little Yak! you lost your aileron!
Lets hit the right wing some more... still not enough...
10th time lucky:
'BOUT BLOODY TIME!
Lets take his left wing off for good measure:
NO!... titanium on the left denies hispanos.
TOTAL:
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AT LEAST 23 hispano hits and the Yak3 was still flying. In fact, it was even shooting at another plane some point in the middle, with both wings leaking fuel, smoke trailing from the engine and only 1 stabilizer still attached. I say at least 23 hits because this is what I can count from the screenshots. There were many overlapping hits that are difficult to account for (4 nose hispanos from 200-300 yards...) and some that I missed in the screen shots. An additional volley of 5-6 more hits finally removed the right wing.
This is not simply an issue of distributed hits. The right wing took more than 5 20mm hits and kept intact. The left took at least 12 hits that I can count and then 4 more hits after the right wing fell off, but the only damage was that the landing gear fell out... the cockpit area took multiple hits and there was no sign of pilot wounds.
This is an extreme case, but generally Yaks take a lot of hits to bring down, which I suppose is correct since the Russians designed the Yak3 based on the IL2, with some added armor.