Influence of surface finish on level speed performance
|In order to determine the influence of surface finish on speed
performance, two of the planned five machines have been measured, serial
Nos. 216 and 220, in serial production delivery
condition with normal paint and in a highly polished condition with a
surface finish corresponding to the Galland machine.
Since the flights were carried out within the production test flight program, only four speed data points were determined for each condition, namely at full throttle altitude and at 7000m with combat and emergency power.
Taking into account the dispersion of the measured data points, resulting from this point-based evaluation, and correcting the change of the full throttle height due to the temperature influence, then as a result the following can be stated.
|1.)||With factory No. 220 no gain in speed was recorded from the high-quality, highly polished condition|
|2.)||With factory No. 216, the gain in speed amounts to ~ 3 mph (5 km/h) at and above full throttle height.|
|This result shows that the normal painting should be
regarded as adequate in terms of surface quality and that a further
effort for surface improvement is hardly worth it.
First, however, these results should be supported by further measurements.
In graphs 4 and 5, the measurement points are plotted in comparison to Fw 190 A-1 performance. According to that, the Fw 190 A-2, which is not equipped with FF drum covers on the wing underside, is faster than the Fw 190 A-1 series: 3 – 6 mph (5 – 10 km/h) at combat power and 6 – 9 mph (10 - 15 km/h) at emergency power.
Bremen, den 29.1.1942
|Fw 190 A-2 Werk Nr. 216 level speeds|
|Fw 190 A-2 Werk Nr. 220 level speeds|