WASHINGTON — Boeing expects to deliver the U.S. Air Force’s next F-15EX Eagle II fighter by the end of November, nearly a year after the company originally planned and four months behind its revised estimate.

This F-15EX, the third Boeing has so far produced for the Air Force, took its first two flights on Oct. 27 at Boeing’s St. Louis, Missouri, factory, the company said in a social media post.

Rob Novotny, Boeing’s director of F-15 business development, said in a Thursday interview with Defense News that production for the fourth F-15EX is complete, and its delivery will follow shortly after the third.

But Novotny also acknowledged Boeing’s F-15EX production has not been as quick as the company wanted, and that the Air Force has expressed its displeasure with the pace and production problems.

“In short, we missed our mark,” said Novotny, a former F-15 pilot, wing commander and brigadier general for the Air Force who joined Boeing in April. “The government knows when they thought they were going to get them and how hard we’re working to get it to them, and they know that we’ve been late. Those conversations are never fun.”

Those aircraft are the first two F-15EXs Boeing produced as part of lot 1B, which follow the two lot 1A test aircraft delivered to the Air Force in spring 2021. F-15EXs include multiple upgrades over previous versions of the fourth-generation fighter, including advanced avionics and improved electronic warfare capabilities.

The F-15EX is also expected to be able to carry up to 12 air-to-air missiles, more than any other Air Force fighter.

Deadlines

Problems with the F-15EX’s production and quality caused the delivery schedule to slip over the past year. The Government Accountability Office said in a weapons system assessment report earlier this year that Boeing originally expected to start delivering the first of six lot 1B aircraft in December 2022.

Boeing missed that deadline, GAO said, mainly due to a supplier’s quality problems with a critical part in the fighter’s forward fuselage that is necessary for flight safety. GAO addedthat the Defense Contract Management Agency found Boeing mis-drilled holes to install the windscreen on four fighters due to a faulty tool.

In that report, GAO said Boeing had since shifted its plans and expected to deliver the third F-15EX in July 2023, and the fourth a month later.

A November delivery date, as Boeing now expects, would represent a further four-month delay from that most recent goal.

Novotny said Boeing’s shift to a new manufacturing approach to build F-15EXs, called full-size determinant assembly, was more difficult than expected and contributed to delays.

That approach, which Boeing already used in production of commercial aircraft, takes advantage of modern manufacturing processes such as 3D drawings and the automated drilling of holes in components. It is intended to produce more precise and accurate holes so parts can be easily fastened together without the use of shims or match drilling.

But getting the tooling and other quality measures right, particularly with a workforce that was using this technique for the first time, “took us a lot more learning than we thought,” Novotny said. “We kind of blew through some of our timelines on the manufacturing process.”

Boeing said in a follow-up email that after a redesign of the F-15EX’s forward fuselage, the company moved assembly work from South Korea to St. Louis. While the company is working on refining this assembly process, the company noted, the change cost it time on the lot 1B aircraft.

Novotny noted Boeing has learned lessons from the early days of using this manufacturing approach on the F-15EX, which the company will use on the next lot of fighters. The company is starting to realize the benefits that this approach, along with digital engineering, can yield, he added, and is now producing F-15EXs faster.

Novotny said Boeing’s schedule estimates going forward will be more accurate, but noted the supply issues from subcontractors presented a challenge.

“If a supplier is late, I can’t deliver a fully assembled F-15EX because I’m waiting on a [stabilizer] actuator,” he said. “The delay is an aggregate of a wide variety of challenges that our entire global supply chain [has experienced].”

“The supply chain realities of today’s world are running on a razor’s edge, and our defense-industrial base has been running on a razor’s edge,” he added. “When I aggregate the entirety of a supply chain over a two- or three-year period to build an F-15, mild perturbations can have significant ripples two years down the line.”

More fighters

Novotny said the fifth and sixth F-15EXs are now undergoing final assembly and should be on the ramp in a few weeks. The third through sixth Eagle IIs are slated to go to Eglin Air Force Base in Florida to continue operational testing, he added.

The final two fighters for lot 1B, which will be the first combat-coded aircraft, should be finished after the holidays, Novotny said. The Air Force will receive them by the end of the first quarter of 2024, after which they’ll go to the Air National Guard, he added.

Boeing has revamped the leadership of its F-15 team, both on business development and program management, aiming to “bring in new eyes on the program,” Novotny said. Around the same time as he joined Boeing, the company also brought on a new vice president, Mark Sears, to oversee its fighters, including the F-15EX.

Boeing has also drawn its F-18 and F-15 production teams more closely together, Novotny noted. The two fighters are still manufactured on their own lanes, he explained, but the “strategic merging” allows more data and lessons to be shared between programs.

“We’re finding commonalities between what is a very mature and successful F-18 line, and porting those over to the F-15EX line, which is new,” Novotny said. “We’re seeing our quality assurance team sharing quite a bit of lessons learned on Hornet that work in Eagle.”

Some of those production tips the Hornet team suggested have already resulted in more quickly completed tasks, Novotny said, and he expects more improvements will continue.

“We’re done making excuses,” Novotny said. “We’re done with apologies. We want to start delivering for the warfighter; we’ve always delivered for the warfighter. … I’m confident we’re going to get going on track.”