Focke-Wulf Fw 190A poor high-altitude performance

[Graham Boak]

It is not a function of radial engines. It is largely a matter of superchargers and the maximum compression ratio. All single-stage supercharger engines begin running out of power around 20000ft. The radial BMW 801 was no different to the inline Sabre, hence the problems with accepting the Typhoon into a Fighter Command that increasingly emphasised high-altitude performance. For performance at higher altitudes the US went to turbochargers, the UK to two-stage superchargers, the Germans to exotic fuel additives. This was partly a matter of available materials, turbochargers requiring exotic metals the Germans lacked; and available expertise, RR being particularly good with superchargers.

For additional altitude, aerodynamic advantage can be gained from larger wings, either by increased span or greater aspect ratio (span divided by mean chord, or span squared over wing area). The Fw 190 has a low aspect ratio wing, so loses out here. Consider the Ta 152H.....

[Harri Pihl]

Originally Posted by Graham Boak

For performance at higher altitudes the US went to turbochargers, the UK to two-stage superchargers, the Germans to exotic fuel additives. This was partly a matter of available materials, turbochargers requiring exotic metals the Germans lacked; and available expertise, RR being particularly good with superchargers.

The Germans were going towards two stage mechanical superchargers as well. There were numerous such projects, the development was just slow. The Jumo 213E was the only such engine to reach the service in some degree.