A compact actuator (20) is arranged to selectively move an airfoil surface
(27) relative to a support (27) relative to a support (21). The actuator
includes a gear reduction unit (24) mounted on the support. The gear
reduction unit has a ring gear (25) adapted to be rotated about a
longitudinal axis (x--x), and a pinion (26) mounted on the ring gear. All
bearings for the pinion gear are physically located within the gear
reduction unit. The pinion gear engages a rack (23) attached to the
airfoil surface such that rotation of the pinion gear will move the
airfoil surface relative to the support.