109 e4 performance

[Crumpp]

So basically the French achieved 494 kph at 600 m with rpm 2400 and 1.303 atm pression d'admission
Extrapolating pessimistically to 0m they got 478 kph with rpm 2400 and 1.289 atm pression d'admission

Quick ballpark of the data to standard conditions….

478 kph TAS x 0.539956803 nautical miles at +5C = 258KTAS

We don't have a piece of the puzzle which is the atmospheric pressure for that day. I am not looking for it but if somebody finds it, I will refine the calculation.

258KTAS x 1.0299 SMOE for our density altitude Temperature difference = 265 KTAS

265KTAS / 0.539956803 = 492kph

492 kph is within 1% of Mtt stated mean of 500kph over a range of 5%.

If we had the pressure and I wasn't using some quick rules of thumb of a standard atmosphere chart but did the full calcs, I bet it would give even better agreement. The French might have had an optimistic performing Bf-109!!

The French test results give very good agreement with Mtt's published figures for the type.