KC-46 Upgrade Roadmap Coming, May Chart End of Boomers

KC-46s nearing completion at Boeing's Everett, Wash., facility. Staff photo by John A. Tirpak.

EVERETT, WASH.—The Air Force and Boeing are preparing a roadmap for improvements on the KC-46 aerial tanker, which has not yet even entered service, and among the possible changes may be the automation of the boom operator crew position.

Mike Gibbons, Boeing Vice President and program manager for the KC-46, told several reporters at the company’s Everett, Wash., plant on Thursday that “all programs” have an improvement roadmap, and in a “phase two” of the plan, the boom operator position might be eliminated, making the refueling operation “fully autonomous.” It might even have been possible to have eliminated the boomer function on the first generation of the KC-46, Gibbons said, but the Air Force wanted to reduce risk on the program and, once requirements were set, was loathe to make costly changes.

The boom operator could be replaced by a combination of artificial intelligence and light detection and ranging (LIDAR) sensors, he said. Airbus demonstrated such a capability with its boom-equipped A310 tanker a year ago.

Other improvements could be to make the tanker a true communications network node in the sky, and to replace obsolescent communications equipment, Gibbons said. A first iteration of the roadmap may be put together in time for the fiscal year 2020 program objective memoranda—the Pentagon’s five-year acquisition plan. Gibbons noted, however, that what’s in the plan will vary with budgets and the emergence of new technologies.

767-2Cs—the basis f?or KC-46 tankers—lined up at Paine Field in Everett, Wash., on Thursday. They are awaiting conversion into tankers. Staff photo: John A. Tirpak

Boeing officials, in a media program meant to provide reassurance that the KC-46 is on track, explained that two deficiencies identified in a recent Government Accountability Office report on the tanker are understood and that work is in progress to correct them. One is an issue with the Remote Viewing System, which allows the boom operator to see, in three dimensions, the refueling operation at the back of the aircraft from his station behind the cockpit. In certain lighting conditions—which Sean Martin, company air refueling test operator, said are almost impossible to reproduce in simulation and difficult to recreate in actual flight—the sun can obscure the refueling operation when it is extremely low on the horizon, or when it creates high-contrast shadows on the refueling connection. The solution is to adjust the controls by which the boomer can adjust lighting on the tail, making the controls “more intuitive,” and fine-tuning the software, he said. The situation occurs on less than five percent of missions, he said.

The other problem involves uncommanded disconnects of the refueling hose when using the probe-and-drogue system. The disconnect occurs when the pull on the hose exceeds 620 pounds, or when the hose bends a certain amount within a certain proximity to the aircraft. “It’s a simple fix,” KC-46 test program manager Jeanette Croppi said. “The situation is unacceptable, but it’s just a matter of when we are going to fix it.” The automatic disconnect is a safety feature, Martin explained, and what is required is a “tuning” of the software controlling how the hose plays out.

“The Air Force will accept” the aircraft even with the deficiencies, because the aircraft still meets requirements, but Boeing is making a “no-expense-spared effort” to correct the issues, even though “it costs the taxpayer nothing,” Gibbons said. Boeing must make any corrections to the KC-46 on its own dime, given the fixed-price nature of the KC-46 contract.

Boeing must absorb all development expenses beyond the $4.9 billion provided for in the contract. The company recently restated its pre-tax write downs on the KC-46, and those expenses now amount to over $3 billion. Boeing has said it expects the KC-46 will be profitable in the long run because of foreign sales and the potential inside track on the second phase of tanker recapitalization. The KC-X contract, for which the KC-46 was selected, involves 179 aircraft out of an Air Force planned fleet of 450 tankers.

Another issue raised by the Air Force regarding the tanker’s performance is the potential for the boom to scrape the receiver aircraft away from the protected area around the refueling receptacle. On a stealth aircraft, such an event could damage low-observable materials, potentially compromising the stealth jet’s ability to penetrate enemy airspace. The KC-46 has no way to detect whether the boom has made contact with the receiver aircraft away from the receptacle.

Boeing Defense Systems chief executive officer Leanne Caret said the scraping issue is “not new,” and that the problem has occurred on other tankers before. There was no requirement that the KC-46 have a mechanism for detecting such contacts, she said, saying only that Boeing and the Air Force are looking at the problem “as a team.”

While Caret insisted that Boeing will fulfill the contract requirements that call for 18 tankers to be delivered by the end of this calendar year, the Air Force has said it is not optimistic the company can achieve that goal, expecting the 18 deliveries in mid-2019.

Reporters were shown completed 767-2C airframes at Paine Field in Everett, in various stages of being modified into KC-46s. The mods involve installing refueling gear, defensive systems, radar warning receivers, military radios, and other items. Boeing has made exhaustive efforts to “analyze and re-analyze” processes in the conversion, Gibbons said, to eliminate any extra or redundant efforts in cutting panels, and in the order in which equipment is installed to improve workflow. There are some 34 airframes in and around the Everett KC-46 conversion facility being built into KC-46s. In addition to the four test aircraft, four are nearly completed.