I was watching some WWII footage recently and seeing planes attack ground units and it had me wondering if there were any instances of ground units killing the pilot using basic weapons (not AA). Whether it is a head shot kill to the pilot, or a crippling shot to the engine i'm just curious if this has ever happened.
This could be in any war, not necessarily WWII
I'm sure there are more examples, but the most famous one I can think of is the Red Baron.
Although the identity of the shooter is still ambiguous, it's fairly widely accepted that Manfred von Richthofen was killed by a bullet fired from the ground. Richthofen's autopsy found that he was shot from below by a .303 caliber bullet, as used in a variety of British small arms, including the Lee Enfield, the Lewis gun, and the Vickers machine gun. (Source)
I would imagine that as aircraft design and doctrine improved over the decades, the usefulness of small arms in taking down planes would diminish significantly - however, I am only speculating, and I will leave it to an expert to expand further.
Ive heard the anecdote, that the Viet Cong had a "rule of thumb", whereby if you held your thumb out ( in the thumbs up sign) at arms length and a helicopter was larger than your thumb, you could hit it with small arms fire.