Numerically the most important of all Japanese float seaplanes during World War II, the Aichi E13A monoplane (of which 1,418 were produced) originated in a naval staff specification issued to Aichi, Kawanishi and Nakajima in 1937 for a three-seat reconnaissance seaplane to replace the six-year-old Kawanishi E7K2 float biplane. A prototype was completed late in 1938 and after competitive trials with the Kawanishi E13K in December 1940 was ordered into production as the Navy Type 0 Reconnaissance Seaplane Model 1. Early aircraft were embarked in Japanese cruisers and seaplane tenders the following year and, carrying a single 250kg bomb apiece, flew a series of raids on the Hankow-Canton railway. Soon afterwards E13A1 floatplanes accompanied the Japanese 8th Cruiser Division for reconnaissance patrols during the strike against Pearl Harbor in December 1941. Thereafter, as production switched to Kyushu Hikoki KK at Zasshonokuma and accelerated, the seaplanes (codenamed 'Jake' by the Allies) were embarked in the battleships and cruisers of the Kantais (fleets), including the battleship Haruna and cruisers Chikuma and Tone of Vice Admiral Nagumo's Carrier Striking Force at the Battle of Midway. Because of mechanical problems with the ships' catapults there were delays in launching one of the four E13Als to search for the American carriers at dawn on the crucial 4 June 1942, depriving the Japanese of the vital initiative during the early stages of the assault on Midway. Furthermore the Chikuma's E13A1 was forced to return early when it suffered engine trouble, further reducing the all-important search area. One of the other 'Jake' pilots, from the cruiser Tone, eventually sighted the American fleet but at first failed to report the presence of carriers, causing a further 30-minute delay in arming the strike aircraft awaiting orders to launch from Japanese carriers. As it was, when the Americans launched their first strike, the pilots found the decks of the carriers Akagi, Kaga, Soryu and Hiryu clogged with aircraft which should have been attacking the American fleet. In all, it is estimated that by mid-1943 more than 250 E13A1s were at sea aboard Japanese ships, though their use was severely curtailed whenever American fighters were in evidence. Nevertheless they continued to serve right up to the end of the war, many of them being ultimately used in suicide attacks on the huge American invasion fleets closing on the Japanese homeland.
The most modern aircraft supplied to the Royal Thai Navy were six Aichi E13A-1s, three in 1942 and three more in June 1944. When the first Aichi's were delivered, the 1st naval Squadron was upgraded to a Naval Wing. The naval Wing had two bases, at Sattahip and at Chalong Bay. The Aichi E13A-1 was a three seat, twin float reconnaissance aircraft. The Aichi E13A-1 was known to the Allies as "Jake". Their endurance made them very suitable for long patrols over the Thai coastal waters and the Gulf of Thailand, in support of Imperial Japanese Navy operations. Included among the various kinds of missions flown by the Aichi E13A-1s were naval escort, patrol and SAR. The USAAF used B-24 Liberators for bombing missions and mine laying operations along the Thai coast. Apparently, the last three E13A-1s were a gift by the Imperial Japanese Navy, IJN, as a thank you for good support during its operations. According to an unofficial source, the IJN provided the three additional E13A-1s after RTN warships and coastal units had downed at least one USAAF B-24 Liberator. Again, little is known about the Royal Thai Navy use of its Aichis. One of them was destroyed at Chalong Bay on July 24/25, 1945. Five were still in service at the end of the war. In RTN service, the Aichi E13A-1's were painted in the standard IJN colours, dark green upper sides and light grey undersides, with black cowling and a yellow identification stripe. A white, or possibly yellow, roundel with a black (or dark blue) anchor were painted on the upper and lower surfaces of the wings and on the fuselage. A Thai national flag was also painted on the fin. Shortly after the end of the War, all the remaining Japanese aircraft in RTN service were decommissioned and withdrawn from use. This was due to an informal agreement with the Allies. The Royal Thai Navy continued to operate some light aircraft, but new combat aircraft in the shape of Fairey Firefly Mk I's weren't delivered until the late 'forties.
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Aichi E13A Jake - seaplane Japanese Aircraft in Thai Military Service