LONDON – The U.S. Air Force has chosen RAF Lakenheath in the U.K. as its first base for the F-35A in Europe.

Two squadrons of F-35s will be located at the airbase, with the first aircraft due to arrive in 2020.

But the arrival of the aircraft will coincide with significant upheaval in the USAF’s basing structure, most notably in the U.K. That is where nearby RAF Mildenhall – home to the Air Force's only European-based aerial refueling squadron – will be closed and handed back to the U.K. The Boeing KC-135 tankers and a co-located special operations group flying the Lockheed Martin MC-130J Commando II and Bell-Boeing CV-22 Ospreys will move to bases in Germany.

The changes are a result of the U.S. Defense Department's European Infrastructure Consolidation (EIC), a two-year-long study to downsize the number of sites and facilities being used by U.S. forces in Europe.

The results of the EIC announced in Washington on Jan. 8 mainly affect U.S. Army facilities in Germany, the Netherlands, Belgium and Italy, with a total of 15 sites closing. Air Force operations at Lajes Field in the Portuguese Azores island chain will also be downsized, European Command (EUCOM) said.

The U.K. was hit particularly hard. On top of the closure of Mildenhall, the intelligence-gathering and support facilities at RAF Alconbury and RAF Molesworth will also close and be consolidated into the communications base at RAF Croughton, Northamptonshire.

Both Alconbury and Molesworth are due to close in 2022.

The Defense Department says the EIC and F-35 basing decisions will result in a net decrease of about 2,000 U.S. military and civilian personnel in the U.K. into the early 2020s due to the removal of about 3,200 U.S. personnel from RAF Mildenhall. This will be offset by the addition of about 1,200 U.S. military personnel who will be stationed alongside the two F-35 squadrons at Lakenheath.

Announcing the EIC results at the Pentagon, Assistant Secretary of Defense for International Security Affairs Derek Chollet said the process was based on that used for the the Pentagon's Base Closure and Realignment (BRAC). It was approved by senior officers who wanted to reduce infrastructure costs without impacting manpower, which currently stands at 67,000 personnel from all the U.S. services stationed in Europe.

Chollet said annual savings as a result of the changes would be more than $500 million a year after the process was complete.

The closure of Mildenhall alone is expected to save the DOD around $125 million a year.

Two squadrons, each with 24 F-35As, will be based at Lakenheath, eventually replacing two squadrons of F-15E Strike Eagles and a single unit of F-15Cs currently based there. The F-15Cs had widely been expected to be withdrawn following the fiscal 2014 budget. But issues in Ukraine and the need to reassure NATO’s eastern states seem to have caused the aircraft to be kept in Europe longer. It is currently unclear when the F-15s will finally leave Lakenheath.

Eucom officials told Aviation Week that Mildenhall’s KC-135s would move to Ramstein air base in Germany, while the Special Operations Group would move to Spangdahlem air base. This is due to occur "within seven years," according to a U.S. Air Force Europe (USAFE) statement.

A final closing date for Mildenhall has yet to be decided, but the divestiture process for the base is due to begin in 2019.

But officials have said they do plan to keep facilities to support deployments of the intelligence-gathering RC-135 fleet in Britain. Mildenhall is currently home to the 95th Reconnaissance Squadron, a unit that does not have any aircraft assigned to it but is responsible for the regular detachments of RC-135 Rivet Joints and its associated derivatives to the U.K.

Now that the U.K. is operating the Rivet Joint, it has been suggested that the Air Force deployments could also operate from RAF Waddington, Lincolnshire. But this has not been confirmed by either the U.K. defense ministry or the DOD.

British Defense Minister Michael Fallon welcomed the decision to base the F-35s at Lakenheath. He said basing the U.S. jets close to the U.K.’s F-35 base at Marham, just 20 mi. away, would provide "opportunities for training and wider support partnerships, including flight training simulation."

Gen. Frank Gorenc, commander of U.S. Air Forces in Europe and U.S. Air Forces Africa, said "we understand these changes will have substantial impacts on the local areas. But we are dedicated to working closely with our community neighbors, defense partners, personnel and families to ease the impact of these transitions as much as possible. These infrastructure consolidations will allow USAFE-AFAFRICA to better meet alliance mission requirements."