This is a very interesting photo from the Japanese side showing the ground-use of air weapons.
The US recovered such ground installations of the IJN's Type 99 20mm MG in the Marshall and Mariana Islands.
Both the Mk.1, Mk.2, flexible & fixed mount types.
https://t.co/XkFNjrLibz https://t.co/BvFazycNRC https://t.co/C7n8LYoSxf