provide a radio beacon for the planes. When I-123 arrived off the French Frigate Shoals in late May 1942, however, she found the U.S. Navy seaplane tenders and already operating U.S. Navy flying boats there, and Operation K-2 was cancelled. As part of Submarine Squadron 3, I-171 then was ordered to join other units of her squadron — the submarines , , , and — in the Pacific Ocean between and , tasked with intercepting American reinforcements approaching Midway from the main Hawaiian Islands to the southeast. During the Battle of Midway, fought from 4 to 7 June 1942, I-171′s squadron mate I-168 torpedoed the aircraft carrier , but the rest of the patrol line had no impact on the battle, and I-171 saw no action during the battle. The Japanese suffered a decisive defeat and cancelled the invasion of Midway. I-171 concluded her patrol with her arrival at Kwajalein with I-174 and I-175 on 20 June 1942. Fourth war patrol On 8 July 1942, I-171 departed Kwajalein on her fourth war patrol, tasked to conduct a reconnaissance of Fiji and the Samoan Islands during the patrol. Between 16 and 24 July 1942 she operated in the Fiji area, then, after reporting no ships in the harbor at Suva, proceeded to Samoa, where she reconnoitered Pago-Pago on 28 July 1942. On 29 July 1942, she fired a single torpedo at an unidentified merchant ship off Tutuila, but missed. She concluded her patrol by arriving at Truk on 12 August 1942. I-171 departed Truk on 17 August 1942 bound for Japan. She arrived at Kure on 24 August 1942 and underwent an overhaul there. Aleutians campaign After the completion of her overhaul, I-171 spent the winter, spring, and much of the summer of 1943 involved in the Aleutian Islands campaign, which had begun in mid-1942. On 15 February 1943, she left Kure to carry supplies to the Japanese garrison on Kiska in the Aleutian Islands, arriving there on 26 February 1943. She departed Kiska on 2 March 1943 and proceeded to Paramushiro in the Kuril Islands, where she arrived on 18 March 1943. After refueling from the oiler on 20 March 1943, she departed Paramushiro on her fifth war patrol, operating in the Bering Sea in the vicinity of as part of a submarine scouting line. After an uneventful patrol there, she returned to Japan, arriving at Yokosuka on 6 April