Seeking ID of strange "cheese grater" device on below cockpit window of some 1940 He111s

[Andy Saunders]

Originally Posted by janus4

These are wooden push out blocks that contains the storage for signal flares

Fascinating. How exactly does this work? I am aware of apertures for the firing of signal pistols from aircraft but am just puzzled, from a technical viewpoint, as to how this operates. Is it a firing mechanism for flares? Or just stowage? If the latter, I am still puzzled! Presumably the flares are loaded from outside, plugged with wooden plugs and accessed from inside the cockpit? I am just puzzled!!