balance tabs

balance tabs

balance tabsclick for a larger image
Auxiliary airfoils used to balance, either fully or partially, the aerodynamic loads on the control surfaces, thus reducing stick loads. These are actuated automatically and move in the opposite direction to the control surface on which they are mounted. A balance tab assists the movement of controls, and its movement is dependent on that of the main member.
References in periodicals archive ?
Meanwhile the UK Air Accidents Investigation Branch, commenting about a serious incident that occurred during an EasyJet Boeing 737-700 post-maintenance test flight, noted that an informal verbal debrief - rather than a written one - by the crew to the maintenance organisation about a pitch trim imbalance led to the elevator balance tabs being adjusted in the wrong direction, making the problem worse.
There were therefore no written instructions and this led to the small, moveable balance tabs on the tail of the aircraft being moved in the wrong direction and this led to the "pitch-down incident" in the January flight.
The report said: "The absence of a formal post-flight debrief and formal written record resulted in the balance tabs, attached to the elevators of the aircraft, being adjusted in the opposite sense to that identified as necessary by the (December) flight test.