A mechanism for adjusting the orientation of an end effector (e.g., a non-destructive inspection sensor) during movement over a contoured surface, comprising: (1) a pneumatic or spring-loaded plunger shaft that facilitates positioning of an end effector onto a highly contoured surface by allowing a wide range of vertical motion; (2) a rocker pivotably coupled to a distal end of the plunger shaft, the rocker being pivotable about a horizontal axis to allow a pair of follower wheels coupled to distal ends of the rocker arms to follow the contoured surface and keep the end effector oriented correctly relative to the surface without tipping over; and (3) a hozzle (i.e., an end effector holder) attached to the rocker for rotation therewith, the end effector being coupled to the hozzle by an elastomeric gasket or a plurality of springs which allow the orientation of the end effector relative to the hozzle to change in response to contact forces.