Crowned spinner on the fw189 and bf108

[danielprates]

This one is driving me crazy: what is the purpose of the "crowned spinner" found on some 1930s planes? Like the one seen here:

 

https://www.alamy.com/stock-photo-close-range-reconnaissance-aircraft-focke-wulf-fw-189-original-caption-131473504.html

 

I saw a video of the startup of a bf108 and it was spinning before the propeller, so it seems independent. My guesses are: 1. Its either a part of a innertial starter; or 2. It could be part of the blade pitch mechanism.

 

Anyone knows?

Edited December 22, 2019 by danielprates

[Raven109]

@danielprates See https://ww2aircraft.net/forum/threads/fw-189-prop-spinner-question.36427/

 

The wind spins the spinner, this rotation is used to adjust the prop-pitch.

 

Here's the full manual. Page 5 describes the function: https://www.deutscheluftwaffe.com/archiv/Dokumente/ABC/m/Motoren/Argus/Verstell Luftschrauben Anlage Argus/Verstell Luftschrauben Anlage Argus.pdf

 

I'm always amazed at how many moving parts there are in an aircraft engine, considering all its supporting components.

 

 

Edited December 22, 2019 by Raven109

[Bremspropeller]

Prop-blade automatic.

 

Some newer planes (like Zlins) also use it.

 

[danielprates]

Ah, I suspected that was it. Allright, thanks!