A problem that sometimes occurred on the Sabre was a recycling undercarriage.   If this occurred one had to synchronise the pulling out of the undercarriage circuit breaker as the undercarriage locked down.   As the circuit breaker was under the left elbow and difficult to reach we had a piece of string tied round it as a tail that made it easier to pull it out.   (Click to see the pictures from the Sabre Mk.4 Pilots Notes)