Space Shuttle Attitude Director Indicator (ADI) manufactured for NASA by Lear Siegler, in its original gray 6″ x 6″ x 9.25″ housing. The Lear Siegler label affixed to the side reads: "Indicator, Attitude-Director, Design Act. 35351, Part No. 158400-01-02, Buyer Control No. MC 432-0235-0002, Trace. Class. Serial 011, Date of Mfg 12-81." Also bears a Lear Siegler repair label from 1982 on the top. In fine condition.
Featuring a design closely resembling the Flight Director Attitude Indicator (FDAI), this important instrument gave the Space Shuttle crew attitude information as well as attitude rate and attitude errors. The orbiter's attitude was displayed on the enclosed black-and-gray ball (commonly known as the 'eight ball') that was gimbaled and marked with numbers indicating angles. The ball moved in response to software-generated inputs to depict the orbiter's attitude in pitch, yaw and roll.
Provenance: The Spaceflight America Museum and Science Center in Prince Frederick, MD, and accompanied by the museum's display placard attributing the ADI to the Space Shuttle Discovery: "The ADI shown was removed from Space Shuttle Discovery (OV-103) in September 2002 during the Major Modification (OMM) period at the Kennedy Space Center, when the cockpit was upgraded to the Multifunction Electronic Display Subsystem (MEDS), or 'Glass Cockpit.' This ADI was used by the Space Shuttle Commander."
