Not a terribly difficult maneuver
Mmmm... I remember some poor soul trying to teach me, and I now try to teach others. It is a very simple manoeuvre
once you understand what you are trying to achieve. To get to that stage, safely, is far from easy, since you are having to co-ordinate 2 "rates" (roll and pitch). From the number of fatalities, frights and VNE exceedences I would therefore disagree with your statement
A 1G barrel roll would be impossible...
Agreed in the classic sense. Reviewing that video, firstly TJ never describes it as a Barrel Roll, and nor would I
It is potentially all flown at 1g - he's started rolling, and kept the 1g applied - end result is in the inverted position the nose is well below the horizon and rapidly falling further... so could well have all been done at 1g, but he would have needed somewhat more to arrest the rate of descent
Anyone trying to do Barrel Rolls, please do NB the 1 absolute safety gate - as the nose passes down through the horizon (pitch) the wings must be at or past the inverted position (roll)... if not then check forward, roll upright and try again this time with a higher roll rate / lower pitch rate - do not "pull thru'"
In teaching, I tend to get the student to pitch (only) until their feet are on the horizon, and only now slowly start the roll, while still keeping the pitch going. The common errors are to start rolling too soon / too quickly, and stop pitching up. Only when they have got a grasp of the relationship between roll and pitch do I add ground features / angles off etc.
NoD