Part of the safety and arming system on the WE.177 series was a simple key operated Strike Enable Facility using a cylindrical barrel key similar to those used on gaming machines.
Apart from the laydown requirement, the weapon was also required to be used in a 'Dive Toss' mode from both the TSR-2 (WE.177A/B) and the RAF version of the Hawker P.1154 (WE.177A).