"Mxsmanic" wrote ...

In a coordinated turn, motorcycles move in two dimensions. They lean into
turns to keep the acceleration vector aligned with the center of gravity
and
the plane of the rear wheel.

Yep, you're right, they're identical.

Pretty much, in this context.

Disagree.

First, motorcycles don't necessarily move in two dimensions in a turn. They
are, however, bound to follow the road surface. Which may be flat.. or then
not.

Second, you might also want to ponder what the motorcycle driver vs. the
pilot is looking at.

Maybe the bike rider wants to look at the intended track of his bike on the
road, in order to spot any bumps. Or maybe he just wants to optimize his
turn to the available width of the road and looks at it more broadly. In
either case it would seem to make sense that the rider's sight perception
improves, if he tilts his eyes more parallel to the road.

The pilot, on the other hand, does not look at any road ahead. He's
interested in the nose vs. horizon sight picture as well as the instruments.
That's a different case and it's not self-evident that tilting the head
parallel to the horizon would improve the pilot's turn performance. On the
contrary, especially if the pilot uses the VSI and altimeter to maintain
altitude, it's probably easier to read them with the eyes level relative to
the instrument panel.

Third, it just might be possible that the pilot's stereoscopic vision can
better help him maintain altitude in the turn by visual cues, if he keeps
his head still. When the airplane banks, part of his stereoscopic ability
is transferred to the vertical direction, which may improve his sensing of
climb/descent changes. Whereas the bike driver has no need to be able to
sense movement in the vertical plane, as he is bound to the road surface
anyway.

Fourth, a bike rider leans forward, while a pilot leans back in his seat.
Can have impact on how the head turns in a turn.

I'm not aware of scientific proof of the above, but neither of the reverse.
So until the opposite is credibly shown, I'll contend that a motorcycle is
different from an airplane.