As the U.S. Air Force accelerates studies for its future aerial refueling and cargo fleets, one key point is becoming clear: The service will need to buy multiple aircraft to replace each type.

The Air Force has started an analysis of alternatives for what it calls the Next-Generation Air Refueling System (NGAS) to come online in the 2030s following the acquisition of Boeing KC-46s and to replace the remainder of its Boeing KC-135s. Subsequent to that will be the Next-Generation Airlift (NGAL) program to replace Boeing C-17s and Lockheed Martin C-5s.

• The service is accelerating its mobility recapitalization
• An MQ-25-like refueler could be relevant
• Increased data links and situational awareness required

Gen. Mike Minihan, commander of Air Mobility Command, says these studies show that a series of aircraft—from the small and exquisite to the large and simple—will be needed. “I think there’s an absolute, mandatory need to look at the problem in terms of a system as opposed to just one thing that has to do everything,” Minihan says.

Within the past year, the Air Force has overhauled its refueling fleet modernization plans. Instead of the KC-Y “bridge tanker” program originally planned to follow the acquisition of 179 KC-46s, the service aims to extend the KC-46 procurement by a few dozen and field the NGAS earlier.

“These future mobility concepts may be very different than our traditional ones,” Air Force Secretary Frank Kendall said last fall. “We need capabilities that can survive the threat of long-range air-to-air missiles. You must be able to bring mobility assets into a contested environment.”

Amid the command’s massive Mobility Guardian exercise in the Pacific, Minihan laid out for Aviation Week his vision for the setup of the NGAS. He sees three roles for refuelers. The first, and the bulk of the refueling mission, would be done in very permissive environments—exercises at home and refueling fighters off the coast of California, for example. This could be performed by a typical, commercial-based tanker such as the KC-135s and KC-46s.

The second would be closer to a fight in the Pacific. These aircraft would need to be more survivable and have improved connectivity to communicate with the combat fleet. This would be similar to the upgraded KC-46s, following block upgrades and other enhancements, he says.

Last would be an entirely new type of tanker that is small, survivable and able to operate in the same areas as fighters. “For the high-end stuff that needs to go into the scariest part of the weapon engagement zones, that doesn’t need to be everything,” Minihan says. “That can be a small fleet of very capable aircraft that can be a bucket brigade—that can be the exquisite gas that needs to be [sent] forward so the kinetic team can be successful.”

For this, Minihan wants the mobility forces to take advantage of the Air Force work on its Next-Generation Air Dominance (NGAD) fighter, the Northrop Grumman B-21 bomber and the new plan for uncrewed Collaborative Combat Aircraft. Much money has been spent on these, so Minihan asks: “What of that can I bring into my fleet now and take advantage of?”

Additionally, Minihan points to the MQ-25 Stingray tanker Boeing is developing for the U.S. Navy to be carrier-based and take on the Boeing F/A-18s’ refueling mission.

“It’s not hard for me to imagine that the MQ could get gas, give gas,” he says. “I could put it on station 2 mi. off my right wing, put it on a holding pattern 50 mi. behind me, or I could send it forward 200 mi. into a highly contested environment and have the automation for a person in the loop to make an orchestra of all that.”

The NGAL, which is likely to be renamed the Next-Generation Airlift System, should have a similar approach. The Air Force needs new ways of delivering cargo in a high-threat environment, where traditional airlifters such as the Lockheed C-130 and C-17 would not survive.

It is a question of not only “‘Can I get cargo forward into a high-threat environment?’ but also: ‘Can I get cargo forward to a maneuvering unit that doesn’t have a runway from which I can operate?’” he says. “Does it have to be manned? Can it be unmanned? Does it have to be 10,000 lb. or 5,000 lb.? Can I do vertical lift? Can I do it on an airship [or] a slow-moving low-altitude blimp? There’s a lot of opportunity when it comes to how you approach that.”

Minihan says the command is closely following ongoing experiments such as the Defense Innovation Unit’s blended wing body demonstrator program and DARPA’s Speed and Runway Independent Technologies and Liberty Lifter demonstrator. He says he also has been meeting with the Air Force Research Laboratory on designs that have not been announced. Technology from the B-21 and NGAD should be adopted, he says.

“I want to develop a headquarters that thinks about the next generation of systems, not just when the current generation is failing,” he says. “We need to create a muscle memory and a capability that survives the actual acquisition of the airplane.”

For the current fleet, experiments and exercises such as Mobility Guardian have revealed a critical need for improved connectivity. Tankers and airlifters require better situational awareness and instant communication with combat aircraft and command and control.

“This pounding drum of connectivity in the mobility fleet is paramount,” he says. “If I have to key my mic to know what’s going on, then we are condemned to an old architecture of employing airpower, especially when it comes to cargo and, most important, when it comes to aerial refueling. The Vietnam planners could come in and lay out our scheme if I’m condemned to having to key a mic to know what’s going on or relying on a brief I received 6 hr., 10 hr. or 12 hr. ago.”

During Mobility Guardian, Air Mobility Command aircraft experimented with a series of new connectivity systems. These included the Sierra Nevada Corp. Airlift and Tanker Open Missions System, which uses a small antenna to provide multiple data links and other secure communications with limited modification to the aircraft, Minihan says. Additionally, the Air Force is expanding the Collins Aerospace Real Time Information in the Cockpit data link modification, originally for KC-135s, to other mobility aircraft including C-130s and C-17s.

Lt. Col. Matthew Novotney, the experiment lead for Mobility Guardian, says the overarching goal for these experiments is to move beyond airlifters and refuelers just receiving data. Existing systems such as the Roll-On Beyond-Line-of-Sight Enhancement for KC-135s help the tankers improve their situational awareness, but that does not go two ways.

During the exercise, a major experiment with the Tanker Intelligent Gateway (TIG) system was conducted using a payload similar to that in the E-11A Battlefield Airborne Communications Node. The TIG, installed in a KC-135’s limited cargo bay, sent and received data over several data links, including beyond line of sight, to “tap into the full picture” of the airspace. Novotney says the system is capable enough that an air battle manager could fly on the KC-135 to perform some of the mission traditionally done by aircraft such as a Boeing E-3 AWACS.

Mobility Guardian is the third exercise in which the system was used; it is currently installed on just one KC-135 with the Utah Air National Guard and Air Force Reserve Command Test Center. Congress provided more funding for TIG to help it become a full program.

In addition to data, the Air Force used a new, alternate navigation system called MagNav designed as a collaboration with the Air Force Research Laboratory and the Massachusetts Institute of Technology’s Lincoln Lab. The system, flown on a C-17, taps technology to navigate Earth’s magnetic field, using artificial intelligence to “zero out” the C-17’s interference. The aim is to use magnetic fields to help an aircraft navigate in an environment without GPS.

These promising experiments are just the latest in a series of similar systems being evaluated by Air Mobility Command with no real program of record to show for it yet. Minihan says he wants Mobility Guardian to show gaps in capability that can be closed relatively cheaply by outfitting the fleet with proven, available technology. In turn, it would be mandatory to define the requirements for next-generation aircraft.

“I think we can get there; this is going to be a thing I want to close. I intend to get it at scale,” Minihan says, adding that he would be happy to see similar systems installed in about 10% of the fleet at first, depending on funding. “We have got to infuse this across the fleet. It has got to be there, and I’ll take that as a personal challenge as one to close,” he says.