Most US F-15 fighters in Japan cleared to resume operations; 18 still grounded

Most of the U.S. F-15 fighter jets deployed to the Japanese island of Okinawa have been cleared to resume flying after being grounded for safety inspections following a crash in the U.S., officials said Friday.

The 57 jets were grounded by the U.S. Air Force for inspections after an F-15C crash in the U.S. state of Missouri in November.

Officials on Kadena Air Base, where the fighters are deployed, said 39 F-15s have been cleared and will resume flights starting Monday. Another 17 were awaiting the completion of checks and will remain on the ground, said base spokesman John Monroe.

In a statement Thursday, the base said Air Force maintenance experts and engineers discovered nine F-15s with cracks in their longerons, metal beams that run along the planes' fuselage.

Also, analysis showed about 40 percent of the F-15 fleet had longerons that did not meet the required thickness measurements specified in the aircraft manufacturer's blueprints. Officials were evaluating measurement data for 17 Kadena F-15s, and those aircraft will remain on the ground until further notice.

Another jet was grounded for unrelated maintanence, Monroe said.

"The F-15 is critical to the defense of Japan and for maintaining peace and stability in the region," Brig. Gen. Brett T. Williams said in the statement. "Our priority in resuming flight operations is to fill our operational taskings and requirements for the defense of Japan, and to do it safely."

The U.S. Air Force said more than 700 F-15s are in its worldwide inventory. F-15s fly from bases in the U.S., England, Japan and the Middle East.

The U.S. Air Force has been using the F-15 since the mid-1970s.

The U.S. military operates bases on Okinawa under a bilateral security pact. Okinawa is about 1,600 kilometers (1,000 miles) southwest of Tokyo. Japan's Air Self-Defense Force said inspections of its 200 or so F-15 jets had found no problems.