KC-46A’s Remote Vision System (RVS), which the boom operators use to connect the boom with receiving aircraft. It’s a critical system on the Pegasus and fundamental to its ability to operate as a tanker for receptacle-equipped aircraft from the U.S. military and its allies.

It’s also a new kind of technology for Air Force refueling aircraft. The service’s previous tankers have all had position for the boom operator to physically lie in at in the rear fuselage, from where could watch the boom directly with their own eyes and guide it into the receiving aircraft. The KC-46, in contrast, has the boom operator seated in the aircraft’s main cabin where they perform their task via the RVS. Since this is a hybrid 2D/3D system, the operators wear special glasses that are, at least in principle, supposed to provide enhanced depth perception while viewing through a flatscreen.

[…]

“The camera feed does not accurately show the end of the boom — there’s about another foot and a half beyond what is visible on the screen, so boom operators use the shadows to gauge where the tip is before connecting to the receptacle. If there’s no shadow, on a cloudy day, for example, the operator has to rely on experience, rather than technology, to make the connection.”

[…]

“Even with the 3D goggles, depth perception is difficult. Moving the refueling boom around the F-16’s canopy to then line up with the receptacle, flying at 290 knots, is a delicate process. While wearing the goggles, the center of the screen is sharp, but when you look to the edge of the screen, it gets blurry and disorienting.”

[…]

an Air Force official explained to Defense News that “There is a slight difference between the motion viewed in the RVS versus what is actually occurring in the physical world.” That now seems as if it might have been a serious understatement.

At one point in the Mobiliy Guardian maneuvers, for instance, the weather during the sortie prevented a C-5 Galaxy strategic transport aircraft from taking on fuel, when “direct-sunlight washout” meant the RVS screen was no longer useable.

[…]

the RVS has a fundamental problem to begin with and that the shadows, in particular, have been used by boom operators as a workaround. Furthermore, it seems to be apparent that the effects of shadows can be both a solution and a problem, depending on the context.

Amid all the other difficulties that have faced the KC-46, the RVS has surely been the most enduring one. It’s for this reason that work is now underway on an ‘RVS 2.0’ that will provide all-new equipment, including a laser ranger to measure the distance between tanker and receiver, color rather than black and white screens, plus augmented reality for the boom operator.

[…]

it emerged that the ongoing effort to redesign the boom, costing $100 million, could likely have been avoided had the Air Force taken note of problems that had emerged much earlier in the program.

Alarmingly, a technology readiness assessment (TRA) — which assesses the maturity of critical hardware and software technologies — also revealed that Boeing engineers used no new or novel technology in the design of the boom because the design was “based on that of the well-proven KC-10 [refueling boom] and the control laws [were] based on the Italian KC-767A and Japanese KC-767J control laws.”

“We reviewed the preliminary design review documentation and found that it showed a refueling boom design that differed significantly from the proposed design that the independent review team documented in the TRA report,” the Pentagon’s Inspector General states in a recent report into the KC-46 program.

Source: KC-46A’s Long-Troubled Vision System Can’t Even Reliably Show The End Of The Refueling Boom

Bet the US wishes they hadn’t recanted from the Airbus tanker they originally chose.