Big John wrote:

Robert

You talk about doing a LOOP in association with a roll. A LOOP has no
roll in it.The ailerons are only used to keep the wings 90 degrees to
the plane of the loop. A IMMELMAN or CUBAN EIGHT has a roll
associated with part of a loop.

The description of making a corkscrew inside a tube is another way of
defining the flight of the airplane when it does a BARREL ROLL.

As a lurker here who has never and will never do a single loop or roll, it
seems to me you two are both describing exactly the same maneuver but using
slightly different words.

Both you and Bob agree that the barrel roll consists of having the airplane
follow a corkscrew path as if it were following the inside wall of an
imaginary barrel, or tube, in the sky.
If the plane were to roll while going straight down the long axis of the
tube it would be an ordinary "slow" roll. OTOH, if the plane were flying
along the inside circumference (i.e. at 90 degrees to the long axis) of the
tube it would be doing loops. The corkscrew path of a barrel roll is
halfway between these two situations (i.e. at about a 45 degree angle to
the long axis of the tube), so it doesn't seem unreasonable to describe it
as the combination of a loop and a roll.