Lot #4162
Apollo Block I Flight Director Attitude Indicator

The Apollo '8 Ball'—an early Block I FDAI
This lot has closed

Estimate: $15000+


The Apollo '8 Ball'—an early Block I FDAI

Scarce Apollo Block I Command Module Flight Director Attitude Indicator (FDAI), contained in its original 8″ x 8″ x 9.75″ housing. The original Honeywell tag is absent, but the unit bears two light red inspector's stamps on the side. Stenciled below the electrical port in white, "C29-2A52." In fine condition. Manufactured by Honeywell, this square version was the first type of this piece of equipment.

The red, black, and white ‘8 ball’ was used to define the relative position of the spacecraft in three-dimensional space. The pitch attitude is represented by the large semi-circles (horizontal relative to the numbers on the ball). The yaw attitude is represented by the small circles (vertical relative to the numbers on the ball). The semicircle immediately under the ‘wing’ is the current pitch angle. The two 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. Indicator has its original glass interface with three white bars over the top, which showed the error in each axis, from the desired value, by the displacement of the right and bottom of the ‘8 Ball,’ and also has its three rate needles on the sides of the display. Originally designed to be three different panel instruments, the astronauts, many of whom were pilots, lobbied for an all-in-one device similar to the artificial horizon indicator in airplanes.

Due to the size, weight, and/or fragile nature of this item, we ask that you call RR Auction for a shipping quote.

Auction Info

  • Auction Title: Space & Aviation
  • Dates: #538 - Ended October 18, 2018