May 22 (UPI) -- Three U.S. senators called on the Government Accountability Office on Friday to investigate delays keeping the KC-46 military aircraft from use in missions.
In a letter, Sens. James Lankford, R-Okla., Jeanne Shaheen, D-N.H., and Maggie Hassan, D-N.H., demanded "periodic assessments" of the progress made by builder Boeing to fix longstanding problems of the cargo and refueling plane, notably its refueling boom and its rearward-facing remote vision system.
In addition, the plane has been prone to cargo locks becoming unlocked in mid-flight, and inspections have found tools, rubbish, leftover parts and loose fittings in planes delivered by Boeing since January 2019.
"The KC-46 aerial refueling tanker modernization program, currently assessed at a cost of about $43 billion, is one of the Air Force's highest acquisition priorities," the letter reads in part.
"The Air Force contracted with Boeing in 2011 to develop, test and produce up to 179 aircraft. The first 18 KC-46 tankers were expected to be delivered by August 2017.
"However, the program experienced significant delays due to a variety of issues... [the] U.S. Transportation Command has decided not to use the aircraft in operations until the critical deficiencies are fixed, which is not expected to occur until 2023."
Boeing has offered to redesign the rear vision system -- a process that would take until 2023.
Each of the senators represents a state in which KC-46 planes are housed on air bases, and Gen. Stephen Lyons, chief of the U.S Transportation Command, has counseled against a proposed Air Force plan to retire some its KC-10 and KC-135 tankers, some of which are 60 years old, in favor of the KC-46.
Lankford and Hassan serve on the Senate's foremost oversight committee, the Homeland Security and Governmental Affairs Committee, whose requests are given priority by the GAO.