"Andy Hawkins" wrote in message
...
Hi,


Just read that section of the book for my PPL exam. I *think* that
spoilers
can be used differentially for roll control, whereas speedbrakes both pop
up
together so can't control roll.

But I'm probably wrong


Andy,

Spoilers deploy together symmetrically. What you are thinking of are
Spoilerons. Spoilerons come into play at slower speeds (typically when the
flaps are deployed beyond a certain point) to improve roll control at slower
airspeeds. Instead of the spoiler panels coming up symmetrically on both
wings to kill lift, only the panel on the wing with the "up" aileron will
deploy. Next time you are in an airliner watch the aileron/spoileron panels
work together at slower speeds. When the aileron moves up the corresponding
spoileron panel will move with it.

Mish