It's a long, long time since he was a pilot and, sadly, demntia appears to be affecting his memory.
'if a loop is performed with sufficient skill, even at the top of the manoeuvre when the aircraft is upside down, the pilot could keep a positive loading of just one āgā ā which is to say, the forces acting on the plane would be the same as if it were the right way up. He often demonstrated the truth of that by flying his (non-aerobatic) light aircraft low over the airfield, pulling up into a loop and landing off the bottom of it'
None of this makes any sense at all. A 'loop' carrying plus 1 over the top cannot, by any stretch of the imagination, be classified as a loop - it will be some sort of egg-shaped monster with, most importantly, a speed at the five-eights of about mach f**king 3.
Norm has become a dangerous lunatic.