Course Indicator MN-97 Omni-Mag (ID-249/ARN)
This Cold War / Vietnam War era Course Indicator MN-97 Omi-Mag was made by Bendix for use in aircraft of the US military and commercial carriers. In military applications of the 1950/60's this was known as the ID-249A/ARN or ID-249/ARN as used in the AN/ARN-14 Radio Navigational System (see illustrations). It also was used in the USAF strategic bomber B-52 and the jet fighter F-100 Super Sabre (see illustrations).
According to Flight Magazine dated 1957,
The MN-97 O.M.I. is a combination instrument embodying the functions of an omni-bearing selector, a flight path deviation indicator, an ambiguity indicator, and a relative magnetic heading stabilizer. The RMI requires an additional source of gyro-stabilized magnetic heading information. The presentation includes a to-from window with sense indication displayed when the aircraft is on or near the selected radial and a vertical pointer for all navigational services. The pointer maintains its center position as long as the aircraft is on VOR or ILS course; a flag alarm indicates "off" when the signal strength is too week for use. Included on the casing are a knob for course setting and a marker beacon indicator light.
This example appears to have been modified as the front labels for Glide Slope and Marker have been blacked out. The face is in good condition and the SET knob rotates the course heading digits at top. It is clearly experienced but would make a nice display artifact. Measures 3.25 inches diameter and ~7 inches long.