The dual-redundant trim RHC/panel enable/inhibit switches on panel F3 provide signals to the GPCs, prohibiting software execution of the associated RHC and panel trim switch inputs while in the inhibit position. The enable position is not wired to the GPCs, permitting the RHC and panel trim switch inputs, which allows trimming.

When the trim RHC/panel switch on the left side of panel F3 is in enable, the commander's RHC trim switches command vehicle pitch and roll rates in major modes 304 and 305 (entry) and major modes 602 and 603 (return to launch site). The three trim switches on panel L2 for the commander are used to move the aerosurfaces in roll, pitch and yaw.

When the trim RHC/panel switch on the right side of panel F3 is in enable, the pilot's RHC trim switches command vehicle pitch and roll rates in major modes 304, 305, 602 and 603. The three trim switches on panel C3 for the pilot are used to move the aerosurfaces in roll, pitch and yaw.

Redundancy management processes the two sets of switches. If two switches generate opposing commands, the resultant trim command in that axis is zero.