But the overseas unveiling comes on the heels of a new government watchdog report outlining new concerns for the KC-46 program, and amid continued challenges with manufacturer Boeing Co. regarding assembly line inspection.
Dr. Will Roper, assistant secretary of the Air Force for acquisition, technology and logistics, said it will take some time for the new inspection process to become standard at Boeing's production facility. The inspections are supposed to correct actions that set back the program earlier this year.
The Air Force in April cleared Boeing to resume aircraft deliveries following two stand-downs over foreign object debris (FOD) -- trash, tools, nuts and bolts, and other miscellaneous items -- found scattered inside the aircraft.
Roper on Monday said more FOD issues were discovered within the last week.
"It's slowing down deliveries," Roper said here during the airshow.
Currently, the production is averaging one aircraft delivery to the Air Force per month, well below the rate of delivery the service had expected, Roper said.
"We're currently not accepting at three airplanes per month, which was the original plan. But we're not going to be pushing on a faster delivery schedule in a way that would put the rigor of the inspection at risk," he said.
All aircraft under assembly are supposed to be swept routinely for debris. Loose objects are dangerous because they can cause damage over time.
The first halt in accepting KC-46 deliveries occurred in February, and the decision to halt acceptance a second time was made March 23, officials said at the time.
"We're just going to have to stay focused, have to continue verifying through these inspections, and what we hope we'll see is that [detection will happen earlier] for total foreign object debris to come down," Roper said.
On top of the FOD issue, a new Government Accountability Office report says that the KC-46 -- which has had its share of issues even before the FOD discoveries -- has a long road ahead for fixing other setbacks that still plague the aircraft.
The GAO found that while both Boeing and the Air Force are aware of or have begun implementing solutions to fix the aircraft, the repeated repairs and recurring delays in the program will likely cause other hiccups in the company's delivery requirement, according to a report released June 12.
As previously reported, one of the main issues surrounds poorly-timed testing. But GAO said a new issue lies with delivery of the wing refueling pods, which would allow for simultaneous refueling of two Navy or allied aircraft, or for aircraft that do not use a boom system.
Since the company did not start the process for testing the wing refueling pods on time, GAO found, it is not expected to meet the delivery date for the pods, nearly 34 months after the delivery was originally planned.
"Boeing continued to have difficulty providing design documentation needed to start Federal Aviation Administration testing for the wing aerial refueling pods over the past year, which caused the additional delays beyond what [GAO] reported last year," the report said. "Specifically, program officials anticipate that the Air Force will accept the first 18 aircraft by August 2019, and nine sets of wing aerial refueling pods by June 2020 -- which together with two spare engines constitute the contractual delivery requirement contained in the development contract."
GAO officials noted the Air Force still grapples with other previously-known problems with the aircraft. For example, the service said in January said it would accept the tanker, which is based on the 767 airliner design, despite the fact it has a number of deficiencies, mainly with its Remote Vision System.
The RVS, which is made by Rockwell Collins and permits the in-flight operator to view the refueling system below the tanker, has been subject to frequent software glitches. The first tankers were delivered in spite of that problem.
The systemic issue, which will require a software and hardware update, may take three to four years to fix, officials have said.
GAO estimates it will take the same amount of time to fix and FAA-certify the tanker's telescoping boom, which has previously been described as "too stiff" for lighter aircraft to receive fuel.
"The KC-46 boom currently requires more force to compress it sufficiently to maintain refueling position," the report said. "Pilots of lighter receiver aircraft, such as the A-10 and F-16, reported the need to use more power to move the boom forward while in contact with the boom to maintain refueling position."
Pilots also pointed out the same power is needed to disconnect from the boom, which could damage the aircraft or the boom upon release.
The solution requires a hardware change and "will then take additional time to retrofit about 106 aircraft in lots 1 to 8," GAO said. "The total estimated cost for designing and retrofitting aircraft is more than $300 million."
It's unclear if the latest findings will impede prospects for future international sales, especially at the Paris air show.
Jim McAleese, expert defense industry analyst and founder of McAleese & Associates, said that the KC-46 is still the U.S.'s latest aviation program, and international partners will be curious about it.
"Now that [the Air Force] is accepting deliveries, KC-46 is high visibility for international sales," McAleese recently told Military.com.
Acting Air Force Secretary Matt Donovan on Monday said its presence is key to showing U.S. capabilities abroad regardless of "minor" issues.
"KC-46 really is a great airplane," Donovan said. "What we're talking about here are sort of minor things when you take a look at the whole capability of the airplane."
Roper added, "The foreign object debris is not a reflection of the end-state performance. We're not happy with how FOD is being handled ... but once we get the FOD out of the airplane the hard way, our operators are getting good performance out in the field."
Designated aircraft and aircrew at McConnell earlier this month began Initial Operational Testing and Evaluation (IOT&E), which will provide a glimpse "of how well the aircraft performs under the strain of operations," the release said.
"As the KC-46 program proceeds with IOT&E, participation in the Paris Air Show and other international aviation events serves as [an] opportunity to increase understanding of ally and partner capabilities and proficiencies, while promoting standardization and interoperability of equipment," the Air Force said.
-- Oriana Pawlyk can be reached at firstname.lastname@example.org. Follow her on Twitter at @oriana0214