World War II History

Operation A

Operation A – Japanese naval counteroffensive (19/20 June 1944) planned after the US capture of the Marshall Islands between 20 November 1943 and 23 February 1944, the Japanese high command having appreciated that the next forward move would take the Americans to the Marianas Islands on the Japanese home islands’ strategic doorstep and this able to strike at Japan, Iwo Jima, the Ryukyus (Okinawa) and Formosa, so severing the Japanese maritime links to the Philippines, South-East Asia, and all their raw materials. Operation ‘A’ called for the American invasion force off the Marianas to be attacked by powerful surface forces moving in from the south-west, where they were based close to vital oil supplies.

Under the command of Vice Admiral Ozawa, the 1st Mobile Fleet from Tawitawi was supported by Vice Admiral Ugaki’s Southern Force from Batjan, the two forces rendezvousing east of the Philippines on 16 June 1944, one day after the US forces landed on Saipan in the Marianas. The rendezvous gave Ozawa a fleet of 5 fleet and 5 light aircraft carriers (carrying only very poor aircrew and obsolescent aircraft), 5 battleships, 11 heavy and 2 light cruisers, and 28 destroyers; Vice Admiral Mitscher’s TF58 comprised 7 heavy and 8 light aircraft carriers (with experienced aircrew and modern aircraft), 7 battleships, 8 heavy and 13 light cruisers, and 69 destroyers. The Japanese plan became apparent to Mitscher after the Japanese rendezvous was spotted by US patrol submarines, and the scene was thus set for the climactic Battle of the Philippine Sea (also known as The Great Marianas Turkey Shoot) on 19/20 June 1944, which resulted in the utter decimation of the Japanese carrier strength, especially in the Imperial Japanese Navy’s last reserve of combat-experiences aircrew.

Ozawa launched a first air strike early on 19 June, bu the radar-warned Americans intercepted this initial wave 50 miles short of the US force, shooting down more than 200 Japanese aircraft. US submarines had meanwhile attacked Ozawa’s force, torpedoing the carriers Taiho and Shokaku, both of which sank. The Japanese second strike, launched at 14:00, was intercepted on its way to Guam and again the Japanese aircraft were decimated, some 100 aircraft being lost. Thus Ozawa had by the end of the first day lost 2 carriers and more than 300 aircraft, whereas the Americans’ losses were come 35 aircraft and slight damage to one battleship.

Imperial Japanese Navy aircraft carriers Zuikaku (foreground) and Kaga (background) head for Pearl Harbor in November 1941 prior to the initiation of the Pacific War.

It was now the turn of the Americans, and Mitscher launched his aircraft from 16:24 on 20 June as TF58 pursued the Japanese fleet that was withdrawing to the north-west to refuel. The American strike sank two tankers and the carrier Hiyo, damaged the carriers Zuikaku, Junyo and Chiyoda and the heavy cruiser Maya, and destroyed another 65 Japanese aircraft, for the lost of 20 of their own aircraft. It was night by the time the American aircraft headed for their parent carriers, which Mitscher ordered to turn on their lights as an aid to the pilots. Nevertheless some 80 US aircraft ran out of fuel and ditched, most of their crews being saved. Operation ‘A’ and the resultant Battle of the Philippine Sea or “Marianas Turkey Shoot” may thus be seen as marking the end of the Imperial Japanese Navy’s air arm as an effective weapon.

Share on Facebook