Dave Stern examines how radio countermeasures were created by the US Army Air Forces during the war in the Aleutians
For the second time since the war of 1812, American territory was invaded on 6-7 June 1942, when the Japanese sailed toward the 1,100-mile, 279-island archipelago of small volcanic Aleutian Islands. The Japanese Imperial Northern Area Fleet consisted of the carriers Ryujo and Jun’yo, five cruisers, 12 destroyers, six submarines, four troop transports and auxiliary ships.
Their initial strike occurred on 3-4 June, when the carrier’s Aichi D3A ‘Val’ and Nakajima Ki-27 ‘Nate’ bombers with Mitsubishi A6M Zero fighters attacked Unalaska Island’s Dutch Harbor military base, including the airfield, seaplane base, submarine dock and a navy radio direction-finder (RDF) station, dubbed Station King. The fleet then sailed to the end of the Aleutians and pre-mapped Kiska Island with its excellent harbour, initially landing 500 Imperial Japanese marines, followed by 1,250 Imperial Japanese Navy troops: a force later estimated at 6,000 men.