KC-46 Tanker Lands in Japan As Part of Long-Range Test

A Boeing KC-46 landed at Yokota AB, Japan, on Oct. 23?, marking the first overseas stop for the new tanker. Air Force photo by Osakabe Yasuo.

A Boeing KC-46 Pegasus tanker landed overseas for the first time, stopping at Yokota AB, Japan, on Oct. 23 local time, as part of an “Integrated System Evaluation” test, the Air Force acknowledged Wednesday. It was the last overseas visit on a trip that started at Edwards AFB, Calif., with an interim stop at Hickam AFB, Hawaii. After Yokota, the jet will fly to Seattle, Wash., to continue testing.

The ISE tests the aircraft’s “military utility” and capability for worldwide operations, the Air Force said through a spokeswoman. During the 10-day, 40-hour evaluation, testers are evaluating “equipment interoperability, supportability, defensive capability, and operational capability” of the aircraft “in an operational environment,” the spokeswoman said.

Air Force and industry officials added that exercising the navigational aids and communications equipment and assessing the integrated mission suite were key elements of the test. Officials said the jet did not exercise with the Japan Air Self Defense Force. The JASDF operates its own 767-based tankers, but the KC-46 is a later and more advanced design.

The jet is one of six in the KC-46 test fleet. Five are all-up KC-46s, complete with all refueling gear, while one is still a 767-2C, which is the basic airframe without the air refueling equipment installed.

Testing of the aircraft proceeds while Boeing works to satisfy Air Force requirements to certify the first group of aircraft for operational duty and get cleared for delivery of the remainder of the 18 jets that were to have been in service by the end of this calendar year. Certification of the tanker to refuel the F-15, for example, could come in the next two weeks.

Boeing is still working to resolve some “Category 1” deficiencies, which the Air Force deems significant enough to delay delivery. They include stiffness of the refueling boom during initial contact, an inability for the boom operator to detect additional loads put on the boom by the KC-46 pilot, and outstanding issues relating to undetected contacts with the receiver aircraft away from the refueling receptacle and with display of the refueling operation at the boom operator’s station.

Boeing has acknowledged the company will miss the October deadline for delivering the first 18 jets. The Air Force has not publicly discussed any corrective contract action in response.

The service awarded Boeing a $2.9 billion production contract in September for 18 KC-46s plus spares, support gear, spare engines, and Wing Air Refueling Pods (WARPs). The deal put Boeing under contract for a total of 52 aircraft. The first two production lots, for seven and 12 aircraft, respectively, were awarded in 2016, and a third, for 15 aircraft, was awarded in early 2017. The program is to yield 179 tankers, to be delivered by the end of 2028. Test aircraft will be converted to operational duty once testing is complete.

Due to delays and redesigns necessitated by discoveries in development, Boeing has absorbed some $3.5 billion in overages on the fixed-price KC-46 contract.