After a Harrier crash at the Paris air show in the early 70’s, the crash was attributed to a side slip of .17g, whilst in the hover, I was tasked to introduce a yaw auto stabiliser system into the Harrier MK 1. The system would apply rudder (Puffer) should a side slip occurred turning the aircraft in the sideslip direction. This model is of a harrier Mk3 of 1 Squadron based at RAF Wittering.