The Reason for Ground Control Intercept Units
The participation of the RAF at Omaha Beach was first considered in mid-1943 when Operation Overlord was being conceived at the highest level of Allied command. It was recognised that the Allies’ superior technology in radar had already played an important part in winning the Battle of Britain, and with continued advancements in knowledge and equipment, pin-pointing incoming enemy aircraft with increasing certainty was helping both day and night fighters reduce the threat of the German air force as the war progressed.
The boffins within the RAF radar section were improving the capabilities of what radar could deliver to the frontline troops on almost a monthly basis, and it was recognised that the technology would exist to allow mobile radar stations to be moved at short notice with the aid of vehicle-born equipment, offering the promise of close support radar virtually on the front line.
In order that these mobile units could function to their maximum capability, the men of the RAF radar section needed to train to allow them to become self-sufficient and independent as much as possible as they moved with the front line across France.
Hitherto, RAF bases had been land-borne and static. With the introduction of mobile radar, the operators and management of these sites needed to have different skills that would allow them to be far more self-reliant, independent and multi-skilled in a whole variety of tasks within the theatre of war. The RAF recognised that they would also need to recruit the best radar technicians as well as men who had resilience, independence and initiative. Consequently, in the Autumn of 1943, men who had these skills were selected from the pool of static radar units and “asked” to volunteer to form new GCI units which would eventually form the mobile radar units that we know.
The training that these men endured was severe and comprehensive. They were seconded to the combined operations brigade, and endured a commando-style training regime based at the famous Invergarry training base in the Western Highlands of Scotland.
The details of the training are very well recorded in Muir Adair’s history of his time in the RAF and it may be referenced under Men and their experiences: Muir Adair.