on 21 July and 31 August. A pair of Type 13 early-warning radars and an E27 radar detector were installed from 22 to 26 July. From 28 September to 10 October, six racks of 30-tube 12.7 cm anti-aircraft rocket launchers were added. Training of the D4Y and E16A aircrew was slowed by technical problems and was generally conducted from land bases. By 1 October the 634th had on strength 17 D4Ys, of which 6 were serviceable, and 18 E16As, of which 16 were operable. Battle off Cape Engaño and afterwards After the Americans began attacking Japanese installations in the Bonin Islands on 10 October 1944, the aircraft of the Fourth Carrier Division were ordered to prepare for combat by the commander of the Combined Fleet, Admiral Soemu Toyoda. Two days later, the 634th Naval Air Group was reassigned to the Second Air Fleet and began flying to bases in southern Kyushu, among these were nine D4Ys and a dozen E16As assigned to Ise and Hyūga. On 14 October they attacked the aircraft carriers of Task Force 38 near Formosa with little effect and heavy losses. The following day Nakase was promoted to rear admiral. The ships of the Fourth Carrier Division were assigned to the Main Body of the 1st Mobile Fleet, commanded by Vice-Admiral Jisaburō Ozawa. The Main Body's role was to act as a decoy to attract attention away from the two other forces approaching from the south and west. All forces were to converge on Leyte Gulf on 25 October and the Main Body left Japan on 20 October. By the morning of 24 October, the Main Body was within range of the northernmost American carriers of Task Force 38 and Ozawa ordered an air strike launched by the Third Carrier Division (Ise and Hyūga had no aircraft aboard) to attract the attention of the Americans. This accomplished little else as the Japanese aircraft failed to penetrate past the defending fighters; the survivors landed at airfields on the Philippine island of Luzon. The Americans were preoccupied dealing with the other Japanese naval forces and defending themselves from air attacks launched from Luzon and Leyte and could not spare any aircraft to search for the Japanese carriers until the afternoon. They finally found them, but Admiral William Halsey, Jr., commander of Task Force 38, decided that it was too late in the day to mount an effective strike.