Radio Altitude Indicator (Altimeter), ID-14/ARN-1 for Radio Set AN/APN-1 S2 Tracker The clock winds and keeps

The clock winds and keeps time

This indicator has remnants of a service label for the Royal Canadian Air Force

25 inches diameter and ~2

the A-7 Corsair

The K-13 Compensating Gunsight

Radio Altitude Indicator (Altimeter), ID-14/ARN-1 for Radio Set AN/APN-1 S2 Tracker The clock winds and keepsThe WWII era Radio Altitude Indicator, ID 14 ARN 1 was a component of Radio Set AN APN 1, used to measure and indicate to the pilot the altitude over the terrain during flight. Made by Roller Smith. See image of technical description of the system. The Radio Altimeter was used in a number of aircraft of the US Navy where close monitoring of height over terrain was critical, such as torpedo bomber TBM Avenger (see image from TBM Flight Manual), dive