The Mark I land service gun was converted for use in an aircraft by louvring the barrel casing for better air flow, lightening the firing pin to provide quicker ‘trigger to primer’ time and, most importantly, synchronising the gun so it could fire between the propeller blades of the propeller. It did this using the Constantinesco Fire Control Timing Gear. This was a hydraulic system that used impulses to interrupt the trigger mechanism when the blade was in front of the barrel.
The equipment on display here is a ‘short’ version of an original system used for training.
