RNAS Culdrose, 1969: the Sea King was new to the RN, and we still did a lot of things the way that we'd always done with the Wessex, such as hover taxi everywhere.
Cue lonely Hiller 12E on solo sloped landing practise, usual area alongside the ammo dump. Quite predictably, the downwash from a passing King Dipper neatly rolled the 12E in a ball down the slope, unnoticed by all, including the tower over the other side of the field.
Tearful Midshipman eventually makes his way on foot across the airfield, nearly as upset by the accident as by the fact that no one noticed, nor missed him