control system command lights on panel F6 are active during the
entry and RTLS flight phases. Their primary function is to indicate
RCS jet commands by axis and direction; secondary functions are
to indicate when more than two yaw jets are commanded and when the
elevon drive rate is saturated.
modes 301 through 304, up until the roll jets are no longer commanded
(dynamic pressure exceeds 10 pounds per square foot), the roll l
and r lights indicate that left or right roll commands have been
issued by the DAP. The minimum light-on duration is extended so
that the light can be seen even during minimum-impulse firings.
When dynamic pressure is greater than or equal to 10 pounds per
square foot, the roll lights are quiescent until 50 pounds per square
foot, after which time both lights are illuminated whenever more
than two yaw jets are commanded on.
The pitch u
and d lights indicate up and down pitch jet commands until dynamic
pressure equals 20 pounds per square foot, after which the pitch
jets are no longer used. When dynamic pressure is 50 pounds per
square foot or more, the pitch lights, like the roll lights, assume
a new function: both light whenever the elevon surface drive rate
exceeds 20 degrees per second (10 degrees per second if only one
hydraulic system is left).
The yaw l and
r lights function as yaw jet command indicators throughout entry
until the yaw jets are disabled at Mach 1. The yaw lights have no