Flight Director Attitude Indicator (FDAI) with housing removed.
Indicator mounts a ball with three axes of rotation, showing the spacecraft attitude in yaw, roll and pitch.
Short needles on the outer scales indicate attitude rates.
Longer needles over the indicator face show commanded attitudes from the spacecraft guidance system.
Red circles centered at yaw 0 and 180 degree poles indicate where the inertial guidance gimbals are in danger of locking
(gimbals from two axes aligning with each other) causing loss of attitude reference.
Compare with the interior of the Space Shuttle simulator ADI (with Lunar Module simulator heritage).
