F-35 stealth fighters from Hill Air Force Base returned to northern Utah on Tuesday following an inaugural three-week European training mission. And Hill's F-16s — the decades-old predecessor to the F-35 — are midway through a final deployment to Spain.

The concurrent training sessions with U.S. allies come during a major transition for Hill's fleet of warplanes and the thousands of associated employees. By October, Hill's 22 remaining F-16s will be gone, sent to other Air Force bases around the country, officials said. And by late 2019, the base expects its full fleet of 78 F-35As will be in place. It currently has 20 of the modern fighters.

The F-16 Fighting Falcon came to Hill in 1979, the first base to transition to the jet.

Nearly 40 years later, and after numerous deployments — including to the Gulf War, and the wars in Iraq and Afghanistan — eight Hill F-16s and more than 200 airmen are midway through their final foreign training session. Planes and staff from Hill's 388th Fighter Wing, as well the reserve 419th Fighter Wing, are participating in the annual NATO Tactical Leadership Program, taking place at Albacete Air Base. It is a joint training exercise with 10 other countries, where Hill pilots are flying exercises along with20 to 30 aircraft from the other participating countries.

"This is the last time the F-16 will deploy with the Hill designator 'HL' painted on its tail," Col Michael Miles, 388th Maintenance Group commander, said in a news release. "We are extremely proud of the job we have done with the F-16 and we must do our best here at [the training] to preserve the memory of the aircraft that is so dear to our hearts."

Many of the remaining F-16s will end up at Holloman Air Force Base in New Mexico, where Air Force officials hope to ramp up a pilot training program. The Air Force has recently faced a shortage of fighter pilots.

Hill officials have said jobs won't be lost due to the F-16 departure. Many employees will transition to support the F-35s. And Hill will continue to be a repair center for F-16s stationed elsewhere around the country, base spokesman Micah Garbarino said.

Eight of Hill's F-35s returned to Utah Tuesday following their first foreign training mission to Europe. The deployment was part of the Pentagon's European Reassurance Initiative, started in 2014 to show support for U.S. allies after Russia annexed Crimea from Ukraine. Some associated staff remained this week in the United Kingdom, where pilots were training with other U.S. and NATO military aircraft at Royal Air Force Lakenheath.

Crews from the 388th and 419th fighter wings also trained in Estonia and Bulgaria for a portion of the three-week deployment, officials said.

lramseth@sltrib.com

Twitter: @lramseth