Japan loses contact with a Misawa Global Hawk 50 km off Tottori

The Japan Air Self-Defense Force lost communication with an RQ-4B Global Hawk at 12.58 p.m. on 15 September while the aircraft was about 50 kilometres north of Tottori Prefecture over the Sea of Japan. Air Chief of Staff Yudai Morita said the aircraft belongs to Misawa Air Base in Aomori. It was not on a training sortie. He did not name the mission.

Defence Minister instructions issued at 1.29 p.m. told the force to establish the aircraft's status, search at once, check for damage on the ground and at sea, and brief local governments. ASDF aircraft and Maritime Self-Defense Force ships and aircraft joined the search. Chief Cabinet Secretary Minoru Kihara said that as of his afternoon briefing there was no report of damage to anyone outside the Self-Defense Forces. Finding the airframe was the priority.

Debris and the first Japanese loss

The Japan Coast Guard later said an aircraft on the search had seen objects floating off Tottori that looked like part of the reconnaissance airframe. Patrol ships were sent to the same patch of water. NHK and CNA both carried that Coast Guard line. There was still no official confirmation of a crash, only a loss of link and debris that resembled the aircraft.

Kyodo and CNA said this is the first time Japan has lost contact with an RQ-4B since the type arrived at Misawa in 2022. The Global Hawk is a high-altitude, long-endurance unmanned reconnaissance aircraft. The B-model Japan flies has a wingspan of about 40 metres and a length of about 15 metres. It can stay aloft for about 36 hours when it is flown from the ground station. Its job is wide-area surveillance with a sensor suite that works day and night.

Misawa hosts both U.S. and Japanese aircraft. The first Japanese RQ-4B arrived there in March 2022. U.S. Air Force photographs from that delivery show the same type being towed into a hangar on the Misawa flight line. Japan bought the aircraft to watch the sea and air approaches that sit west and north of Honshu, including the same Sea of Japan waters where the link dropped on Tuesday.

What is not yet known

Morita would not say whether the aircraft had gone down. He said the search covered every possibility. The force has not published altitude, heading, remaining fuel or whether a split-link or a mechanical failure came first. It has not said whether the aircraft was on a routine patrol or on a tasked collection flight. Those facts will decide whether this is treated as an airworthiness event or as something that touches operations across the Sea of Japan.

A high-altitude unmanned aircraft that fails over water is easier to lose than a manned patrol plane. There is no crew to report a last position by voice. There is also no passenger risk. The operational cost is the hole in the reconnaissance orbit and the work of recovering a large composite airframe, or pieces of it, from the sea.

By late afternoon the Coast Guard's debris sighting was the hardest public fact after the time stamp of 12.58 p.m. If those objects are confirmed as the RQ-4B, Japan will have lost its first Global Hawk on a non-training flight in the sea it bought the type to watch. The next briefings will have to say whether the other Misawa airframes remain cleared to fly.