AFAIK the term does come from the steam eraJ.A.W. wrote:I heard that "balls to the wall" was an expression derived from the steam era..
.. & relates to when the machine was pumpin' so hard that the balls spinning in the governor - would fly loose..
the governer has hanging weights which move out centrifugally (against their own weight) as the shaft rotates faster
enough rpm and the weights are far enough out to start pulling the mechanism that reduces the steam
the mechanical advantage increases with the outward movement, so this movement becomes large and conspicuous
this is 'balls out' - the normal state of a governed engine eg in a factory turning line shafting at constant speed against variable load
presumably machines were often installed against a wall (so the the governer would naturally be near to the wall)
so 'balls to the wall' was standard full speed
how about 'going ballistic' ?
AFAIK it is a legitimate US fighter pilot term meaning flying at zero-lift-coefficient angle of attack
I believe I have seen it used by such persons
(turn) manoeuvring uses high A0A for high Cl, the resulting high Cd depletes speed, hence degrades manoeuvring capability
so regularly Cl must be reduced (even to zero, this being the quickest way to recover some speed) .... etc
a ball (or ballistic missile) having no wings so always a zero Cl
similarly, 'unload' means reduction of Cl, going ballistic is a subset of 'unloading'
