Editing Stabilator (section)

==General aviation==
[[File:piper.cherokee.pa-28-140.g-bcgj.arp.jpg|thumb|right|Piper Cherokee with stabilator (and anti-servo tab) deflected upwards]]

Because it involves a moving balanced surface, a stabilator can allow the pilot to generate a given pitching moment with a lower control force. Due to the high forces involved in tail balancing loads, stabilators are designed to pivot about their [[aerodynamic center]] (near the tail's mean quarter-chord). This is the point at which the pitching moment is constant regardless of the angle of attack, and thus any movement of the stabilator can be made without added pilot effort. However, to be certified by the appropriate regulatory agency, an airplane must show an increasing resistance to an increasing pilot input (movement).{{citation needed|date=October 2022}} To provide this resistance, stabilators on small aircraft contain an [[servo tab|anti-servo tab]] (usually acting also as a [[trim tab]]) that deflects in the same direction as the stabilator,<ref name="Phillips">{{cite book |last1=Phillips |first1=William Hewitt |title=Journey in Aeronautical Research: A Career at NASA Langley Research Center |date=November 1998 |publisher=NASA History Office |url=https://history.nasa.gov/monograph12/contents.htm |access-date=17 October 2022 |chapter=6. Problems Encountered as a Result of Wartime Developments |quote=the tab on the all-movable tail was changed from a servo tab to a [[anti-servo tab|geared unbalancing tab]]. With this arrangement, the control forces were similar to those on a conventional airplane}}</ref> thus providing an aerodynamic force resisting the pilot's input. General aviation aircraft with stabilators include the [[Piper Cherokee]]<ref name="Abzug"/> and the [[Cessna 177]]. The [[Glaser-Dirks DG-100]] glider initially used a stabilator without an anti-servo tab to increase resistance: as a result, the pitch movement of the glider is very sensitive. Later models used a conventional stabilizer and elevator.