The performance of the Bf 109 F-4

Final words

Still some important pieces of mosaic are missing in the chain of evidence. For the German sources these are the instruction or correspondence with the prohibition of use of the take-off/emergency power of the DB 601 E, as well as the instruction for the abolition of this prohibition.

For the British sources all test protocols of the real test flights in October 1943 are missing. The existing performance data are probably pure estimations on the base of faulty measurements with the Bf 109 F-2 and an extrapolation of these values with the help of the eastimated performance of the DB 601 E.

The source situation permits nevertheless to make some evaluations.

The German sources present for the whole timeframe from sommer 1941 till spring 1943 consistent performance values for top speeds as well as climb ability. There was clearly differentiated between the power settings take off/emergency power and climb/combat power. The period of the initial prohibition of use of the take-off/emergency power of the DB 601 E could be narrowed down very exactly.

For the British sources it is meanwhile clear, that they don't base on any real measurements and are hence almost without any value.

The US sources don't help so in any way, since they base exclusively on the already mentioned British tests and exhibit striking transfer errors.

A German author like Nowarra seems to have known at least the data sheet from Messerschmitt for climb/combat power. Unluckily he mixes up the different engine power settings in his books without giving a hint on this.

Anglophone authors seem to have known the German sources not at all. The performances told by them are all in a range, which is only told by Allied sources.

Finally I'd like to say, that factually wrong statements become not more correct, only because they are repeated for a period of 50 years over and over in dozens of secondary sources. A more attentive and meticulously examination of all sources, would have provided here surely more quality.