No it's not entirely a 1g maneuver. This comes up from time to time.
The entry to the roll initiation can either be considered or not considered
as part of the maneuver. Usually, in the classic sense at least, the entry
to the roll initiation point is considered as part of the maneuver. In this
case, you have to pull above 1g leaving level flight and as such, the g
during this phase of the roll has to be above 1g naturally.
If you have to dive to gain entry airspeed as is the case in low powered
airplanes like say a clipped winged Cub for example, the climb phase into
the roll from the entry airspeed point is also above 1g. Also, if the roll
is done in a way that requires the aircraft to be returned to level flight,
the exit phase as the nose comes back to level flight will also be above 1
g.
I should be a bit more clear when I speak peripherally on barrel rolls, as
many pilots consider them only from the level flight to level flight
scenario; where as in reality, a barrel roll can be performed from almost
any attitude of flight; most of these not requiring a return to level flight
at all....and subsequently not requiring higher entry and exit g.
When I speak of barrel rolls, I should specify that I'm not speaking of the
classic barrel roll entry and exit.
I speak ONLY of the part of the roll beginning at the initiating point where
the aircraft begins it's path through 3 dimensional roll. Because this point
can be executed from various attitudes of flight, it is this point that I
describe as being capable of being performed at various levels of positive g
down to 1g.
In other words, I only consider the aircraft in barrel roll when the flight
path is transitioning through 3 dimensional flight. I use this analogy
because in actuality, a barrel roll can be initiated from flight attitudes
other than from the classic level flight entry.
The actual roll can be performed as loosely down to 1g (I've even done them
completely unloaded) or as tight (higher positive g) as the aircraft's roll
axis through 3 dimensions will allow (in a fighter for example...a vector or
lag roll)
To clarify on your point; if a barrel roll is started from level flight and
ended at level flight, the entry and exit flight path will indeed require
positive g above 1.
Dudley Henriques

"mike regish" wrote in message
. ..
Is it truly an entirely 1 g maneuver? It seems like you would have to pull
1+ G's at the end. The nose goes down and has to be pulle dback up, no?

mike

"Dudley Henriques" wrote in message
...

Well....you can do a barrel roll all the way down to 1g if you have the
right parameters set up and execute properly. As near as I can figure, to
set this up for the 380 you would need about all the sky you could get
both under you and around you!!!:-))
Dudley Henriques