As you might remember, i was the one that brought those charts to AH, just before it was modeled back in april 2001 (hope thats right).
And i spent hours and hours last year to compare AH D9 performance with the one on the charts. I had plenty of help with that from HoHun (Henning).
Also i got a hard copy of the original FW speed chart, together with additional papers. The quality is much better than the scan.
And to get the AH D9 speed, i counted single pixels of the AH D9 speed chart.
I will summarize the results.
AH D9 matches nearly exactly the speed of a real D9 using a JUMO213A, on B4 (87 Octane) fuel and MW50 for special Emergency (curve 4 on the chart).
I think the AH D9 top speed is 430mph max, and 377 mph SL (100%fuel).
The one for the real D9 (curve 4) is 432mph max, and 379 SL.
The 2mph difference, comes from a fact, that i couldnt clear yet.
The FW speed chart is for a weight of 4250kg.
But fully loaded weight for D9 is always listed as 4270 kg, this also appears in this way for the original FW climbchart.
So the 20kg more weight of the AH d9 compared to the one from the chart, will explain the minimal speed difference.
I also want to make a full performance picture of the D9, containing speed, climb and turn and compare this to the AH D9.
But this would need time (especially testing AH D9 performance) that i cant afford yet.
Cause it is bad to trust the gauges and charts from AH, i would like to use data, that was gained by testing the AH D9, so we have the exact informations we need.
But what i can surely say, is that the speed of the AH D9 is not wrong. It matches the speed of the (as far as i know) most comom variant of the D9 in 1945.
A little paradox, but intersting, is the fact that the fastest D9s were the early ones, that used C3 fuel. Those would have the speeds of curve 1) in the chart.
So a D9 of September 44 would have performance equal to curve 1)
and one from January 1945 would have that of curve 4) or that what we have in AH at the moment.
