bozon: The prop and HP will have a huge effect on these curves.
Bigger HP planes will typically drop off much move at slower speeds do to not being able to convert the HP into thrust.
HiTech
So its a prop efficiency effect? I thought props were at their peak efficiency at slow speeds and efficiency does not change that much between good props. If anything, the Yak-3 probably has the highest power loading of the three planes.
Anyway, now that I did the math I realize that there is more than prop efficiency effects. When looking at the ROC/ROC_peak as a function of IAS plot some of the math becomes a little simpler, but still too much to post here - the slope of the back of the power curve (i.e. the drop of the ROC below best climb speed) depends on the power loading with an additional dependency on the absolute mass ("power/mass^2" term in there) which is why the mossie "should" be doing so badly relative to the Yak3.
That still does not necessarily mean that the yak3 is OK - I don't have the numbers or the patience to calculate these graphs from theory, sorry. Maybe something is off with its "e" or "AR" parameters or too much engine power, IDK. It feels like one of those RedBull stunt planes, completely different from the other AH planes except the Spit16 perhaps. Not to mention that it takes as may hits as an F6F to bring down, while being a light, partially wooden, barely armored plane - but that is another topic.
25% of fuel in an A8 gives like 5-6 minutes of fuel on wep.
50% and 4*20mm is more representative for the A8 (base type of A8)
Yes, but for the testing I feared that the A8 will not fly at 110 mph with a heavier loadout...