The first recorded use of a windshield wiper on a WWII fighter aircraft was recorded March 23, 1944. 1st Lt. Flynn Stone was flying his P-51B at 23,000 over the Mediterranean Sea when a migrating stork jettisoned his payload directly on to the Mustang windshield.
Fortunately Lt. Stone's mechanic, TSgt. Barney, had installed an unauthorized prototype test windshield wiper for just such a contingency.
Lt. Stone quickly grabbed the wiper control, concealed as Do Not Push, and pushed.
The X-Wiper was found after the war on an apartment building roof in Helsinki.
Lt. Stone was never found. Nor Barney either.