The received wisdom is that the world’s air forces went to low level on 2 May 1960, the day after one out of a salvo of S-75 ‘Dvina’ (NATO designation SA-2 ‘Guideline’) SAMs brought down the U-2 flown by Francis Gary Powers as it passed over Sverdlovsk. Not so for the RAF, which had been conducting its business at low level since its formation. Two operations that spring to mind are ‘Chastise’, the Ruhr dams raid, and ‘Jericho’, the raid on Amiens prison. Both relied upon the accurate delivery of weapons which required low-level bomb release, especially the Upkeep mine that famously had to be dropped from a height of 60ft (18m) and a speed of 200kt. The aircraft involved had used a low-altitude approach to the target to avoid not just detection by enemy radar, but engagement by enemy flak.