FM's the State of Play with empasis on Climb performance.

[Robo.]

Ernst if you try to follow a 109 in the climb, you'll see the gap is very much real

I appreciate you're trying to get the measurment methodic right, but the fact is the RAF aircraft are, unfortunately, seriously underperforming - no matter how you're looking at it.

Or even better, I suggest you do your own tests and share them with us.

Regards.