TOKYO (AP) -- Japan has grounded its F-15 fighters for the second time in three months after a fuel tank and parts of a mock missile fell off a jet on a training mission, officials said Saturday.
Japan Air Self-Defense Force officials said that the flight suspension involves all missions except emergency scrambles and will last until the safety of Japan's 202 F-15 fighters has been confirmed.
No one was injured in Friday's incident near Komatsu base in western Japan and the pilot landed safely. In July, Japan's F-15s were grounded after one of the jets crashed into the East China Sea. Though presumed dead, the pilot of that jet is still listed as missing, and the cause of the accident has not been announced.
The latest incident comes as Tokyo is moving ahead to replace its aging fighters.
The 350-pound (155-kilogram) tank, which was empty, and parts of the dummy missile detached and fell from the plane as it was nearing the field for landing. The debris fell on 10 locations, including a sewage plant.
"We take this accident very seriously," Gen. Shigeru Iwasaki, the head of Japan's air forces, said at a news conference late Friday. He said the cause was under investigation.
Japan is the biggest foreign user of the U.S.-designed planes but is looking for a newer aircraft to replace its aging fleet. It is expected to announce its choice by the end of the year in a deal worth more than $8 billion.
Because of Japan's close military ties with Washington, options such as the Lockheed F-35 and Boeing F/A-18 have long been the top contenders, but the Eurofighter Typhoon is also being considered.
The deal is expected to involve 40 or 50 new planes.
Though many upgrades and changes to the planes have been made over the years, F-15 fighters have been in service since the early 1970s and are increasingly expensive to maintain. The United States, which also relies heavily on the aircraft, is planning to phase out its F-15s in favor of the more advanced F-35 and F-22.
The Japanese versions of the plane, originally built by McDonnell Douglas, now Boeing, are produced domestically under a license by Mitsubishi Heavy Industries.
Japan has been flying the F-15 since 1982. The plane involved in Friday's accident went into service in 1998.