The A&AEE moved to RAF Boscombe Down on 9 September 1939 at the outbreak of the Second World War and Martlesham then became the most northerly station of No.

The GDA's main focus was on the Port of Harwich, and in July 1940 there were almost daily attacks on shipping off the East Coast, but 302 Heavy AA Battery also had a detachment stationed at Martlesham.

On 15 August the experimental Fighter-bomber unit Erprobungsgruppe 210 attacked RAF Martlesham Heath and a neighbouring signal station.

[3][4][5] On 27 October 1940 another daylight raid was made on Martlesham by about 40 Messerschmitt Bf 109 fighter-bombers, which were engaged by the HAA guns on their way in and out.

The group consisted of the following squadrons: The 356th FG served in combat from October 1943, participating in operations that prepared for the invasion of the Continent, and supporting the landings in Normandy and the subsequent Allied drive across France and Germany.

From October 1943 until January 1944, they operated as escort for Boeing B-17 Flying Fortress/Consolidated B-24 Liberator bombers that attacked such objectives as industrial areas, missile sites, airfields, and communications.

Fighters from the 356th engaged primarily in bombing and strafing missions after 3 January 1944, with its targets including U-boat installations, barges, shipyards, aerodromes, hangars, marshalling yards, locomotives, trucks, oil facilities, flak towers, and radar stations.

Bombed and strafed in the Arnhem area on 17, 18, and 23 September 1944 to neutralize enemy gun emplacements, and received a Distinguished Unit Citation for this contribution to the airborne attack on the Netherlands.

In the immediate postwar years, Fighter Command squadrons were in residence at Martlesham but the proximity to Ipswich and the physical limitations on lengthening the runways restricted jet operation.

The following year, the A&IEU was disbanded and the station was retained in reserve status during which time an Air Sea Rescue helicopter unit was in residence.

It relayed radio communication between the USAF and other US bases in the USA, Iceland, and the UK on the one hand, and Germany and Italy on the other.

It linked via SHF voice and morse radio to Hillingdon, West London, and via large UHF tropo-scatter dishes to the ballistic early warning base at Fylingdales (Yorkshire), Flobecq (Belgium) and the Hook of Holland.

Record Books at US Air Force Maxwell base; US Technical Defense Information Center website online Honeywell tropo-scatter studies; UK Home Office radio frequency records at UK National Archive; East Suffolk Aviation Society websites, including USAF veterans' contributions; East Anglian Daily Times).