There are two
body flap switches: one for the commander on panel L2 and one for
the pilot on panel C3. Each switch is a lever-locked switch spring
loaded to the center position. The body flap switches provide manual
control for positioning the body flap for SSME thermal protection
and for reducing elevon deflections during the entry phase.
The body flap
can be switched from its automatic mode to its manual mode by moving
either switch from the auto/off position to the up or down position.
These are momentary switch positions; when released, the switch
returns to auto/off . The white body flap man (lower half) of the
push button light indicator on panel F2 or F4 is illuminated, indicating
manual control of the body flap. To regain automatic control, the
body flap push button light indicator on panel F2 or F4 is depressed,
extinguishing the man white light and illuminating the auto white
light. The push button indicator can also be depressed to man for
manual body flap control. The push button light indicator is triply
The up and
down positions of each switch have two power supplies from a control
If the commander
and pilot generate conflicting commands, a body-flap-up command
will be output to flight control because up has priority.