WASHINGTON and COLOGNE, Germany — Lockheed Martin and Airbus have agreed to develop a new aerial-refueling service aimed at the U.S. Air Force, upping the pressure on incumbent Boeing to deliver its KC-46 tankers on time.

The two companies, industry behemoths on each side of the Atlantic, hailed the pact for combining Airbus’s A330 Multi-Role Tanker Transport (MRTT) plane with Lockheed Martin’s systems-integration expertise and “presence” on the U.S. defense market. In essence, the joint venture could provide Airbus with another bite at the massive Air Force air-tanking apple after rival Boeing won the bid to build a fleet of new aircraft in 2011.

“The companies are taking a cooperative approach, with the Airbus A330 Multi Role Tanker Transport (A330 MRTT) at its heart, to examine a broad spectrum of opportunities,” reads a Dec. 4 joint Lockheed-Airbus statement. “These may range from ways to support critical near-term air-refueling needs, such as a fee-for-service structure to conceptualizing the tanker of the future.”

The partnership comes as the Air Force is eager to get more tanking assets to meet the demands of the new U.S. National Defense Strategy. In September, the service announced that it will need at least 14 additional tanker squadrons by 2030.

The Air Force plans to buy 179 KC-46 tankers from Boeing so that it can begin phasing out older models, but the company has missed key delivery dates multiple times — most recently this October. And even after Boeing begins delivering planes at a steady clip, there may be a requirement for more than a hundred new tankers beyond the KC-46 program of record.

One thing to watch will be whether the Air Force is amenable to the proposed fee-for-service model involving planes from outside its own fleet.

On one hand, the service has gotten more comfortable in paying companies for flying hours used to help accomplish critical missions where there is an aircraft shortfall, said Doug Birkey, executive director of the Mitchell Institute for Aerospace Studies. One example is the forthcoming deals with private companies to provide aircraft and pilots posing as enemies during air-battle drills, which are anticipated to be awarded next year.

But on the other hand, “in the scheme of acquisition and the Department of Defense, the KC-46 is really not doing that bad at all,” Birkey said.

Richard Aboulafia, a defense analyst with the Teal Group, argued the Airbus-Lockheed agreement makes a lot of sense.

However, it comes with two huge questions: Who pays for the planes that are used to fly missions for the U.S. Air Force, and what kind of a contract is the Lockheed-Airbus team expecting?

“Airbus and Lockheed [could] team up to take that risk. Lockheed is not famous for taking commercial risks. Quite the opposite,” Aboulafia said.

Another confusing note is the companies’ stated desire to begin “conceptualizing the tanker of the future,” according to the news release. Lockheed and Airbus have different core competencies — Airbus as a massive producer of commercial airliners able to divert that technology to low-risk solutions, and Lockheed as a developer of cutting-edge, military-specific aircraft, Aboulafia said.

If the Air Force’s future tanker is a “stealthy, high-tech military aircraft, then Lockheed certainly doesn’t need Airbus,” he said. If the partnership is to build the KC-Y, another airliner-based tanker to follow the KC-46, Airbus has a lot of technology to bring to the table, “but I’m not sure what’s in it for Lockheed.”