Planetaries have been used in aircraft engines from
the get go as that results in the lowest weight design.
Many were bevel plantaries as in this Zepplin engine.

Spur gears have only been used in inline engines (mostly V12s)
to raise the thrust line (P51) or to allow a cannon to shoot through the
hollow prop shaft (ME109).

Paul Lamar

Or the P-39/P-63 Aircobra/ King Cobra, Virg