Shack
I was a QFI at Tarrant Rushton until it closed in 1954. Remember our Vampire formation aeros display for you on 01/01/54 ? I believe the "phantom dive" problem could be exacerbated if a/c had no ventral tank. It could easily happen with a/b "in" at lowish speeds if the a/c yawed. "Always keep the ball in the middle, Bloggs".