Boeing Co. charged the Japanese government an ¡°excessive¡± price for some spare parts for its refueling tanker plane, as much as 16 times more than the U.S. Air Force paid for its latest versions, according to a service assessment.

In one example involving an April $79 million spare parts contract for the KC-46 tanker, Japan was billed for navigation lights made by subcontractor Honeywell Inc. ¡°at a unit price more than 1,500% above the previous unit price,¡± according to the previously undisclosed Air Force summary prepared last month.

From November 2019 until March of this year, the U.S. Air Force tried, without success, to ¡°secure adequate pricing information¡± from Boeing to determine whether the price for the lights and other parts in the package was fair and reasonable under federal regulations, according to the summary.