"Max Richter" wrote in message
...
Hallo,

i am wondering why American aircraftradialengines have no aerodynamical
spinners.Airplanes with inlineengines like P51;P40;P38 and so on have
aerodynamical optimized spinners.
And German radialengines had spinners like the FW190.Zero´s and other
Japanese aircraft had them.
What is the reason why the wellbuild American aircraft had just a little
hup on their propellers.
Thank You and greetings
Max

Hummmmmm, a little before my time but from what I remember from talks with
my grandfather (he was a NAP) and my dad (also a Naval aviator) both whom
flew many different types of radial engine aircraft, I think that spinners
may have disrupted the air flow. Pre-WWII the intake designs being used were
classified. Developed they eventually gave almost a 10% performance
improvement over the designs in use in the rest of the world at the time.
The Jap "Zero" copied an earlier US intake design which added to its
performance, but this design still didn't perform as good as later (early
WWII) designs did. A 10% performance gained in aerodynamics and cooling, all
due to the shape of the cowling was nothing to pass up.

Many, many years have passed since those conversations with my grandfather
and my father. I just wish I had paid more attention to what they said about
their experiences. My grandfather flew for more than 25 years retiring in
1952 with 33 years in, and my father flew for 19 years before he passed in
1961.