On 2007-06-18 07:01:05 -0400, Bob Moore said:

SS2MO wrote

As you continue the roll, you will be at a point 40 degrees off the
origional heading when you have completed 180 degrees of roll and
your wings should be level with the horizion in the inverted position.

How about 90 degrees off the original heading when inverted?

Bob Moore

This is exactly what is causing all the "confusion" on this thread
concerning barrel rolls.
Many manuals (yes, including the Navy) teach ballel rolls as a
precision maneuver beginning from a specified entry and proceeding with
exact heading changes desired at exact points in the roll. The 90
degree heading change at inverted is usually found in this "classic"
description for the execution of a barrel roll.
This is fine if learning to do a barrel roll in this manner is your
goal, but no one in this thread should be misled into thinking that
acheiving these heading changes is REQUIRED to execute a barrel roll.
You can execute a barrel roll as tightly or as loosely as the
airplane's flight envelope will allow.
Putting out here that a 90 degree heading change, or ANY specific
heading change at ANY point in the roll is a requirement for executing
a barrel roll in an airplane is misleading and totally incorrect.
Dudley Henriques