1./ In my research for 'The Burning Blue' I created this map, assembled from Fighter Command records in the National Archive, showing the HF R/T coverage for each of the 11 Group sector stations. This shows for each sector how far that sector's squadrons could be commanded.
Comments
Note that the range for the TR9D HF radio was 35 miles, and this is the range used in the map. However, this range varied according to many factors, including atmospherics.
It’s an aspect of air combat that is often overlooked, the need to adequately communicate over distances is essential.
It was only when we gained the ability to remotely access radios with the ICCS system in the 1990s that we finally evolved away from these 1940s limitations.