As the flight of four F-16s approaches the Air Force’s next-generation tanker, the boom operator presses a few buttons on a digital display in front of her and the jet’s boom system springs to life.
A large black-and-white screen sharpens to a clear image. It shows the refueling boom lowering from the rear of the plane and beginning to move side to side and up and down, testing to ensure it is ready to offload about 5,000 pounds of fuel to each Viper. A familiar “fasten seatbelt” ding plays to passengers to announce the start of the refueling—a reminder that the KC-46, at its heart, is an airliner.
The KC-46 is the sole Pegasus playing in Air Mobility Command’s (AMC’s) large-scale Mobility Guardian 2021 exercise, AMC’s premiere training event held every two years. This year’s iteration is focused on new ways of fighting and the development of new technology. Air Force Magazine attended the waning days of the exercise and is the first independent news organization to fly on a KC-46.
The tanker’s envelope has expanded to fuel more aircraft, and the May 25 morning is perfect for the Remote Vision System (RVS) to show its capabilities.
“Got ’em in sight,” the boom operator says over the radio.
Buzz 21, the first of the four F-16s from the Ohio National Guard, pulls up behind the KC-46, call sign Fred 11. When the black-and-white view of the F-16 is clear through the jet’s 3D view from the end of the boom, you can make out the hoses extending from the pilot’s oxygen mask, as well as the patches on uniform sleeves.
However, 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.
In May, two more major problems arose with the KC-46, beyond the long-standing issues with the RVS and the boom.
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.
The weather above Lake Huron, Mich., after taking off from Oscoda-Wurtsmith Airport—a former USAF base that closed in 1993 and has become a depot and maintenance facility for Kalitta Air—is ideal for showcasing the existing RVS capability that day. A high cloud ceiling prevents the direct-sunlight washout that has plagued the system—during an earlier sortie in the exercise, the screen washed out while a gigantic C-5 attempted to refuel. The only shadow darkening part of the screen comes when the KC-46 lines up directly between the sun and the receiver. That only happens a couple times as the tanker runs its tracks, but when it does, it makes depth perception a little more difficult.
A set of three screens above the main one shows a blurry, wide-angle view of the rear and side of the KC-46, highlighting the heat signature of the F-16 engines.
The first connection with Buzz 21 takes a couple tries, as the operator pulls the boom back several feet to avoid scraping the F-16. “Money,” the instructor says as the connection is made. Buzz 21 takes on its fuel and moves to the right side of the jet. Buzz 22 moves in from the left to take its turn for fuel.
With the ideal daytime conditions, the refueling was “pretty by the book,” said Staff Sgt. Ryan Edsall, a boom operator with the 344th Air Refueling Squadron, who was the instructor on the flight. While the daytime can bring issues with glare and shadows, the RVS system is best at night, he said.
Scenario of the Day
The F-16s are providing defensive counter-air coverage to protect bases in the region from an advancing force, which for the exercise had contracted “Red Air” to simulate Su-35s and Su-30s. It’s “Day 30” of the war, and the enemy is at about 75 percent capability, with simulated SA-8 short-range, air defense systems protecting its key locations across the border. Earlier in the exercise, aircrews focused on tactics for a high-end fight, including takeoffs in radio silence and the first KC-46 night-vision landing. Even the jet’s call sign, Fred 11, is a diversion during the exercise since Fred is a nickname for the C-5. KC-135s are going by Herk, KC-10s are going by Moose, in a small attempt to deceive a would-be enemy.
The tanker is flying a track over Lake Huron to refuel the F-16s, and a nearby KC-10 is refueling two A-10s as part of the exercise. Because of the “stiff boom” Category 1 deficiency on the KC-46, one of several remaining with the program, it can’t refuel the Warthogs because lighter and slower aircraft such as the A-10 have a difficult time disconnecting after refueling. During a pre-mission brief, planners said KC-135s and KC-10s would have to be on standby if A-10s needed fuel, because the KC-46 couldn’t help.
AMC on May 26 said the KC-46 can refuel F/A-18A-F and E/A-18Gs using its drogue without restrictions. The Pegasus can pass fuel, with varying restrictions, to B-52s, C-17s, F-15s, F-16s, F-35As, HC/MC-130Js, other KC-46s, E-3Gs, C-5Ms, RC/TC-135s, F-22s, and B-1Bs. In the coming months, the aircraft is projected to be able to receive limited aerial refueling certifications and clearances for CV/MV-22s, E-8s, B-2s, and P-8s.
The boom operator makes the connection with Buzz 22, Buzz 23, and Buzz 24 on the first try. Then with the operational refueling requirements of the day’s mission complete, the nearby KC-10 swings over and practices making connections with the KC-46. Each time the massive KC-10 connects, the smaller KC-46 shudders passengers who feel a slight push forward.
Flying the KC-46
In the cockpit, the KC-46’s avionics and situational awareness show how advanced it is compared to the older KC-10s and KC-135s. The pilots have plugged the flight path into the jet’s navigation system, and it flies itself on a refueling track. Aside from the better air-conditioning, this is one of the biggest upgrades after coming from a KC-135, said mission pilot Capt. Daniel Dixon, with the 344th Air Refueling Squadron at McConnell Air Force Base, Kan.
“It’s a lot smoother to fly,” Dixon said. “It flies itself a lot more. That allows us to focus on tactical data link and the bigger picture—the other threats to the aircraft—and pay attention to the flight at large, rather than maintaining our air speed and bank angle and making sure that we stay within our airspace.”
The co-pilot on the mission changes one of the screens in front of her to a camera view of behind, showing the KC-10 connecting to the boom.
Another screen in front of the pilots displays the jet’s Tactical Situational Awareness System, bringing in information collected through line-of-sight and beyond-line-of-sight links, displaying nearby jets and threats into an easily viewable display for the aircrew to know what’s around them. This is built in to the KC-46, while the KC-135 relies on a roll-on system for a similar capability, but those are only available in small numbers, are owned by Air Combat Command, and sit in the back of that plane instead of in front of the pilots. A key focus of Mobility Guardian was integrating the KC-46’s system with other Tactical Data Link Systems across the mobility fleet.
Fixing the Main Problem
USAF officials have long said the situational awareness upgrade is a major focus of the KC-46 program, and pilots who have flown the jet told Air Force Magazine it is a huge upgrade, though they are taking small steps to move toward full capability.
The jet’s biggest and most famous issue is the set of cameras, screens, and sensors connecting the boom operators to the receiving aircraft. Boeing and the Air Force announced in 2020 that they had reached an agreement to overhaul the whole system with new cameras, displays, and sensors. The current black-and-white video feed will be replaced by a color 4K view. The boom will be affixed with a new actuator to alleviate the stiffness issue, which will allow the A-10s to be able to connect with the KC-46.
Included in the new “RVS 2.0” package will be a laser ranger for aircraft distance measurement and augmented reality to assist with the boom operations, which should address the problems of depth perception and accurately show the length of the boom itself.
New screens will replace the current ones in the boom operator position, which is reminiscent of a remotely piloted aircraft operator’s cockpit. The new screens and systems will actually move the entire position a few inches, causing a third seat used by instructors and guests to be shifted from the middle to the side.
Boeing will cover the cost of the new RVS system, which is in addition to more than $5 billion in extra costs the company has absorbed.
RVS 2.0 is currently undergoing its preliminary design review, and AMC Commander Gen. Jacqueline D. Van Ovost told Air Force Magazine in an interview she has seen some of that work, and “our boom operators have seen that work, and they are pretty happy with what they see. So, I’m cautiously optimistic.”
As more boom operators have worked with the current system, they have become more confident in working around RVS issues. AMC now wants to open its envelope to more training sorties with combat aircraft. Air Combat Command leaders have flown on KC-46s and seen how it operates and have said “’OK, let’s do this with fourth-generation airplanes,’” Van Ovost said
The new system will start to be installed on delivered KC-46s in 2023, and it will be incorporated on the production line the following year. In the meantime, Boeing has also developed an interim RVS “1.5” using software upgrades to improve the system’s image quality. While the interim step is welcomed by the Air Force, service leaders have said the priority is the full 2.0 overhaul and 1.5 can’t change that timeline.
In May, two more major problems arose with the KC-46, beyond the long-standing issues with the aircraft’s RVS and the boom. The issues center on the aircraft’s receptacle drain line tubes and Flight Management System and the Air Force said they will be fixed at Boeing’s expense.
“There are no operational restrictions on fielded KC-46s due to either of these deficiencies, nor do they affect [Air Mobility Command’s] plan for KC-46 Interim Capability Release,” said USAF spokesman Capt. Joshua D. Benedetti in a statement. “The [System Program Office] and Boeing have established operational processes and maintenance procedures to mitigate impacts and ensure the issues do not add extra risk to personnel, aircraft or operations.”
The air-refueling receptacle drain line developed cracks in low-temperature conditions, according to the Air Force, and Boeing is redesigning the drain tube to address the issue.
The aircraft have also suffered isolated incidents of Flight Management System instability during operations. Boeing and subcontractor GE Aviation identified the need for a long-term software fix, and for the short-term, Boeing is developing updated procedures to ensure the system’s stability in flight.
Months before, the Air Force resolved two other Category 1 deficiencies on the KC-46: a duct clamp that moved excessively and a drain mast on the outside of the tail that could potentially break loose.
Hundreds of less serious Category 2 deficiencies with the aircraft persist, defined as issues that do not impact the safety of flight and have workarounds in place to continue operations.
A Deficiency in Action
One of these Category 2 deficiencies is a feature that was designed to improve safety and ease the burden on boom operators, but is not working as designed due to a software flaw. The Air Force on its own implemented a workaround as the service and Boeing wait for more pressing issues to be solved first.
The issue is with the aircraft’s Aerial Refueling Software, which has preset limits for different types of receivers—aircraft needing fuel—to control the boom’s independent disconnect system. Simply put, the system automatically selects the left/right and up/down limits for the boom to stay connected to a given receiver, and if the movement exceeds the envelope for that aircraft, the boom automatically breaks away to avoid damage.
However, the presets in the system are not accurate for each receiver, so boom operators, before each connection, have to override the automatic preset limits and input correct ones. The problem was a Category 2 deficiency on the KC-46 before the workaround was implemented.
“The Air Force is aware of the KC-46 receiver preset issue,” Air Mobility Command said in a statement. “[AMC] implemented a workaround for boom operators to manually adjust the KC-46 Receiver Presets and closed the CAT II DR for Enhancement. The issue does not impact operational use of the boom, nor will it keep the aircraft from eventually being fully operational. AMC will address a long-term fix for this issue during follow-on upgrades once solutions are met for higher priority deficiencies.”
Boeing said it is working “on a plan to address the issue in a future software revision. In the meantime, operators have a workaround to continue refueling operations.”
Air Force Magazine witnessed the workaround firsthand during the flight of F-16s over Lake Huron. As the first F-16 lined up to receive fuel, the boom operator prepared the refueling system, and the instructor on the flight inputted F-16 into the software. The controls are in a mostly black touchscreen on the lowest panel of the Aerial Refueling Operator Station.
The selection adjusts the green/yellow/red lines on the main monitor that shows the boom and the receiver aircraft trailing behind. The instructor then changes the individual settings to the correct ones, referencing a list of receivers. This changes the length of the color line on the RVS to the correct threshold for the receiver. The system then must be reset between each receiver, as the boom operator also changes the settings for how much fuel will be passed.
After the first Viper broke away, the instructor pilot repeated the process of selecting F-16 as the receiver and then again overrode the preset limits.
Boom operators said the workaround is not a big deal when there’s just one receiver, such as another tanker or airlifter. However, when there’s a flight of multiple aircraft, such as these four F-16s, the process takes a small amount of time between refuelings. Additionally, if there is just one boom operator on the flight, it takes attention away from this process, an issue that was alleviated in this recent mission by having the instructor handle the resets while the boom operator focused on refueling.
“KC-46 aircrew continue to familiarize and increase skills aboard the aircraft,” AMC said. “Their experiences and feedback are critical to identifying improvements in order to provide the best possible weapons system to the Joint warfighter.”
While the KC-46’s automatic disconnect system uses the software settings, the independent disconnect system in the KC-10 is selected manually at the operator station in the rear of the plane.
The Air Force and Boeing did not provide a timeline for a possible software fix, other than saying more pressing issues will be addressed first.
Preparing for Operations
The tanker during the May 25 mission was tail number 76026 from McConnell, the biggest operating base for the KC-46 with more than 100 aircrews trained and flying the jet. The base has sent their KC-46s on an around-the-world mission including a stop at the Dubai Air Show, and on training events in the Pacific and in Europe. Air Mobility Command will offer the KC-46 to U.S. Transportation Command for limited operations as soon as the summer of 2021.
KC-46 crews used the exercise’s operations tempo, and the small, towerless airfield, to practice flying in a combat environment. During the May 25 flight, the KC-46 did a “tactical arrival,” or a “teardrop” landing. This involved approaching the runway from the wrong direction and doing a sharp turn and climb, to turn around and land quickly.
“Traditionally, tankers [fly] very wide patterns, come in and fly [a] very smooth, precise approach to land. We’re used to taking off and landing from the same field at Al Udeid [Air Base, Qatar] or Al Dhafra [Air Base, United Arab Emirates], which is very safe, controlled. And so there’s not a lot of threats nearby,” said Maj. Thomas Gorry, the chief of group training with the 22nd Operations Group at McConnell.
The KC-46 program brings together aircrew from different backgrounds. Gorry comes from a C-130, which regularly flies tactical approaches to austere airfields, so he wanted to bring that approach to the KC-46.
“When you’re thinking about that next fight, the airfield you’re landing and taking off from might not be as secure, so the tactical arrival is another piece to that puzzle that we’re not just good at yet,” he said, adding, “We just don’t know where we’re going to be landing next. It’s not going to be [Al Udeid], and it’s not going to be Dhafra.”
At McGuire, a Wing Girds for Change
A KC-10 Extender took off into the dark and rainy New Jersey sky after a short weather delay to link up with F-22s flying over the Atlantic Ocean, marking the end of an era.
The June 30 flight was a historic one for the Air Force’s second-oldest squadron. It was the last time a KC-10 assigned to the 2nd Air Refueling Squadron (ARS) would fly.
The remaining Extenders from the 2nd ARS have shifted to the 32nd ARS within the 305th Air Mobility Wing, which will become a “super” squadron until the last KC-10s at JB McGuire-Dix-Lukehurst, N.J., retire in 2024. The base will bring on 24 KC-46s. McGuire had 32 KC-10s before retirements began.
“Today, we’re officially a KC-46 squadron,” 2nd ARS Commander Lt. Col. Nicholas Arthur said in a July 1 interview, with the image of a KC-10 still on his uniform name patch. “Our folks that are still qualified on the KC-10 will continue to fly with the other KC-10 squadron until we send them all to training or they get other assignments.”
The process started in earnest about six months ago at McGuire, with the first crews heading to Altus Air Force Base, Okla., to train on the KC-46. There are now six crew members at McGuire qualified on the KC-46, with the number expected to grow before the Pegasus arrives in November.
In the meantime, the squadron is revising its processes and programs to shift from Extender operations to the Pegasus. The squadron’s readiness status dropped, taking the 2nd ARS off of the list of units that could deploy. However, since tankers are in such high demand, remaining qualified aircrews will still deploy with the 32nd.
The Airmen were originally expecting to stop deploying in the spring to prepare for the conversion, but operational requirements increased with the Afghanistan drawdown and other combatant command needs, so these deployments will continue until October.
“Until we send our folks to training, we’re still going to actively deploy them as KC-10 Airmen because our requirements as a community don’t really go away. Every jet we send to the boneyard, our requirements drop a little bit, but there’s still a heavy demand for tankers, and that doesn’t change just because we’re going to convert, and we just have to learn to adapt and make it work,” Arthur said.
To be able to fly the KC-46, pilots head to Altus or another KC-46 location for three months of qualification training, with another one to two months of additional mission qualification training at McGuire. The New Jersey base will bring some instructors in to help, but as the training requirements increase, those training TDYs will continue.
On the maintenance side, the 605th Aircraft Maintenance Squadron (AMXS) has become a sort of “hybrid” unit with an initial cadre of 41 Airmen being trained on the Pegasus, said Master Sgt. Sydney Melton, the 605th AMXS KC-46 Pegasus lead production superintendent. These Airmen go through 16 to 30 days of “Type 1” training at Altus, with different training times for different Air Force Specialty Codes, and then another 30 days of “on the job” training where they are actually turning wrenches on the aircraft, he said.
The KC-46 has new technology in the cockpit and throughout the jet, which will be a change for Airmen used to operating on lower-tech legacy tankers. For communications/navigation maintainers, that will mean some more complicated work.
“There’s going to be some challenges there, but we’re ready for it,” Melton said.
A good thing for McGuire is that multiple bases have already shifted from legacy tankers to the KC-46, and the units communicate their own lessons learned to make the stand-up go more smoothly.
“Every base, both Active and Reserve, is doing everything they can to set us up for success, so it’s pretty cool to see that. A lot of the times, it’s sink or swim. Figure it out. Make the mission happen,” Melton said. “So, to see that we’re getting that kind of support from other bases that don’t owe us anything is pretty awesome.”
In the past few months, maintainers have watched five KC-10s leave to go to the boneyard after years at McGuire.
“It’s kind of an eerie feeling to know it’s going and never coming back,” Chappell said.
“It’s a first love type thing,” Arthur said. “I understand the decisions that were made and why they were made, and, you know, it is an expensive, old airplane to operate,” he said. “But yeah, you know, you’re always going to love your first airplane.”