Beam Approach Visual Indicator Ref 10Q/4 RAF A-30 or in those without the

or in those without the C-1

Judging from the accompanying instructions

See page from F-86 Maintenance Manual dated 1954 showing the location on the instrument panel and confirming the type of the tachometer

BU AERO USNAVY is embossed on its face

The manual covers instruments that were eventually used in aircraft of the Air Corps US Army and Air Force US Army during WWII

Beam Approach Visual Indicator Ref 10Q/4 RAF A-30 or in those without theThis is a WWII and Cold War era Beam Approach Visual Indicator, Ref 10Q 4, Mod 27 as used in bomber aircraft of the Royal Air Force such as the Avro Lancaster (see illustration of the Lancaster instrument panel from the Pilots Notes showing the location of the indicator). Per the Rochester Avionics Archives: The Standard Beam Approach System is similar to the ILS system used in Modern aircraft. Beam Approach Beacon System BABS was a homing device used