[Leica] why do bombs whistle?

[douglas.sharp at gmx.de (Douglas Sharp)]

Interesting, Neil,

The bombs dropped by the Luftwaffe Stuka (JU-87) are supposed to have 
had a siren-like system built in to make them 'scream' even louder when 
dropping to increase the psychological effect.

My father told stories of "screaming" Stukas with AT-cannon mounted 
below the wings attacking his Signals Truck in the Western Desert, 
apparently the dive-brakes of the plane had a similar effect - a 
terrifying sound.

Douglas

Neal Friedenthal wrote:
> One of the reason that bombs whistle is the fuse.  The bomb has a fuse 
> that is in a safe position while in the plane, as the bomb is released 
> the safety pin is pulled and a propeller like device on the fuse spins 
> to arm the bomb.  This propeller causes much of the whistle, as the 
> bomb accelerates during its fall, the pitch increases.  Modern dumb 
> bombs use fuses that lack the external "propeller". Artillery 
> projectiles make more of a shrieking sound due primarily to the shape 
> of the projectile and their tendency to wobble in flight, flat based 
> projectiles tend to wobble more than "boat tailed" or fin stabilized  
> projectiles and tend the shriek more and louder.
>
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