KYIV, Ukraine — One of the handful of F-16 warplanes that Ukraine has received from its Western partners to help fight Russia’s invasion has crashed, Ukraine’s Army General Staff said Thursday. The pilot died.

The fighter jet went down Monday, when Russia launched a major missile and drone barrage at Ukraine, a military statement posted on Facebook said. Four of those Russian missiles were shot down by F-16s, the statement said.

The crash was the first reported loss of an F-16 in Ukraine, where they arrived at the end of last month. At least six of the warplanes are believed to have been delivered.

The Defense Ministry has opened an investigation into the crash.

The Ukrainian air force in a Facebook post identified the pilot as Col. Alexei “Moonfish” Mes, who “saved Ukrainians from deadly Russian missiles, unfortunately, at the cost of your own life.”

Moonfish and a fellow Ukrainian pilot, Andrii “Juice” Pilshchykov, made an early, public visit to the U.S. in June 2022 to press lawmakers and media to send Ukraine F-16 fighter jets and they both continued to serve as public faces for Ukraine’s battle to secure its airspace. Pilshchykov was killed in an August 2023 accident.

“When I met with Ukraine pilots Juice and Moonfish I had a sick feeling they wouldn’t make it through the war,” former U.S. Rep. Adam Kingzinger of Illinois posted on X. “They fought like hell for Ukraine, and the F16.”

Earlier Thursday, Russia conducted a heavy aerial attack on Ukraine for the third time in four days, launching missiles and drones that mostly were intercepted, Ukraine’s air force said.

Russian forces fired five missiles and 74 Shahed drones at Ukrainian targets, an air force statement said. Air defenses stopped two missiles and 60 drones, and 14 other drones presumably fell before reaching their targets, it said.

Authorities in Kyiv said debris from destroyed drones fell in three districts of the city, causing minor damage to civilian infrastructure but no injuries.

Russia’s relentless and unnerving long-range strikes on civilian areas have been a feature of the war since it invaded its neighbor in February 2022.

NATO members Belgium, Denmark, the Netherlands and Norway have committed to providing Ukraine with more than 60 of the planes. That number is dwarfed by the Russian jet fighter fleet, which is around 10 times larger.

Ukraine needs at least 130 F-16 fighter jets to neutralize Russian air power, Kyiv officials say.

Military analysts have said their arrival won’t be a game-changer in the war, given Russia’s massive air force and sophisticated air defense systems. But Ukrainian officials welcomed them as offering an opportunity to hit back at Russia’s air superiority.

Ukraine has until now been using Soviet-era warplanes, and its pilots underwent intense training on the F-16s in the West for months. The usual training period is three years.

President Joe Biden granted authorization in August 2023 for the U.S.-built warplanes to be sent to Ukraine. That came after months of pressure from Kyiv and internal debate in the U.S. administration where officials feared the move could escalate tensions with the Kremlin.

The F-16s can fly up to twice the speed of sound and have a maximum range of more than 2,000 miles. They can also fire modern weapons used by NATO countries.

The Russian military said Thursday it had thwarted an overnight attack on Crimea, destroying three Ukrainian sea drones aimed at the Black Sea Peninsula that Moscow annexed from Ukraine in 2014.

In the meantime, Ukraine’s Army General Staff acknowledged Thursday Ukraine’s involvement in strikes this week on oil depots deep inside Russia.