Coordinated turns and the little ball

"Jose" wrote in message
om...
If the 38 is rolled fast enough at any g above 1g, (with the airplane
loaded) you can couple the roll axis with another inertia axis, usually
pitch in the Talon. Its quite a complex issue, and involves both the
inertial axis and the aerodynamic axis of the aircraft.

Ok, I see it's interesting, but I'm still not sure what it means. Is
"pitch" referenced to the earth or to the (rolling) aircraft axis?

Is it something like "If you are rolling fast, and then stop the roll, the
aircraft will pitch towards the pilot's feet."?

Its a complex model. Basically, you can visualize inertia coupling by
splitting the airplane into 2 basic elements of mass; one element
representing the mass in front of the cg and the other behind it.
There are 2 separate axis systems in play for an airplane in maneuvering
flight. The first axis is the is the aerodynamic axis system acting though
the cg in the relative wind direction, and the other is the inertia axis
acting through the cg lined up with the two mass elements I've described.
If you are maneuvering at say 1g or even unloaded where the 2 axis systems
were in alignment, there would be no coupling in a roll.
But if the inertia axis is inclined to the aerodynamic axis for some
reason....say you had a slight pitch input in play as hard aileron was being
applied (the airplane loaded above 1g,)
now you have a condition where the 2 axis systems are not aligned. As roll
input progresses under this condition, a pitch moment can be produced, and
its the coupling of the two axis systems that constitutes an inertia
coupling.
Dudley Henriques