investigating P-47 Propeller - Visual model vs. Manual

[Im_TheSaint]

I think I spoted an inconsistency between the manuals and the visual model.

As per pictures, the 3d model of our DCS P-47 uses the CE 13' paddle blade propeller, specifically the symmetric type with a narrow base which was indeed used on the d30 and 40 models.

However the manual states a very generic Curtis constant air speed propeller of the size of 12'2". This was sometimes called the toothpick proppeler.

I believe this a accuracy conflict between the manual and the 3d model. On top of this, almost with absolute certainty the manual is wrong. As the "symmetric paddle" prop has been used on models since the P47-d23RE variant. And the performance of the plane in game indicates it's being used instead of the original toothpick prop.

 

More info for enthusiasts:

The original toohthpick prop had lower proppeler efficiency, or rather, the better paddle prop had a much higher efficiency. This efficiency gap would only be enlargened with the higher HP engines which came rather quickly after the plane's A variants. From thrust horsepower calculations based on climb rate difference between the toothpick (in the manual) and the paddle prop (in the 3d model and on the actual planes), the effective thrust horsepower difference for a 2600HP engine, can come up to 400 or more more thrust horespower available (based on data used). Which is a massive difference from just a prop change.

Sobert S. Johnson a P-47 ace, in his book named Thuderbolt! Talks about this prop in some praise "Never again did a Focke Wulf FW190 or a Messerschmitt ME 109 outclimb me in the thunderbolt, the new prop was worth 1000 horsepower more and then some." Arguably his claim of the new prop being worth 1000 engine HP could even be accurate. Given he was flying a 2800+ engine HP plane with an overspun turbo and higher RPM engine, given the old prop's inneficiency in harnessing this power. The new prop on his plane could have performed like having a 1000 engine HP more with the old prop.

Edited June 19, 2022 by Im_TheSaint

[grafspee]

Guy who wrote manual probably missed part about 13" props, this happen quite often, for example DCS manual for P-51 has power/ fuel consumption charts for 1650-3 engine, our P-51D has v-1650-7 engine and DCS model is done for -7, probably same or similar situation here just a DCS manual error

Edited June 19, 2022 by grafspee