Seen that myself. My instructor (RIP, Ned, a motorcycle accident took him shortly afterwards) dived our Whirlwind 10 from 500 feet running in for a turning quickstop at the relief landing ground (Chetwynd). At about 50 feet agl, while pulling the aircraft round in a very steep right turn, he hit RBS. Thankfully for us it was a right turn. The aircraft shuddered then rolled very rapidly left as advertised and left us beyond upright. If we had been in a left turn I'm sure we would have gone inverted and I might have been held to blame as the BOI would have assumed the student was flying. No fire cover or ATC at that airfield... Both of us learned from it. Ned apologised.