Heli Student
To hell with the legals ... I cannot advise on what other display pilots do to produce a loop, but at the highest point (and minimum 'G') of the standard loop manoeuvre I fly, the collective lever is in its LOWEST position. Indeed when practicing in a piston helicopter, I have actually 'split' the rotor and engine speed needles, ie an inverted autorotation. At the 1978 Farnborough exhibition, the MBB 105 pilot, Zigggy Hoffman told me he did the same. Once again... "Don't try this at home without guidance from an experienced display pilot. Dennis K.