Arthur, do you recall a run of Hydraulic Pipe Failures on the BIA Heralds circa 1976-77? It got beyond a joke and usually happened in the late mornings and more often than not the aircraft originated from Blackpool and would end up AOG in Exeter. It happened so often that from the Ops point of view it soon became a sort of head in hands job. The situation only being saved by some good station engineering and the splendid Skippers and their Crews who would agree to 'Go into Discretion'.