A Ukrainian pilot was killed in combat when his F-16 jet fighter crashed Monday, just weeks after the first of the American-made aircraft arrived in Ukraine, according to U.S. and Ukrainian officials.

The pilot, Oleksiy Mes, died while helping to repel a massive Russian missile attack on Monday, the officials said. Initial reports indicate the jet wasn’t shot down by enemy fire, U.S. officials said. The Pentagon referred questions to the Ukrainian Air Force for comment. The Ukrainian Air Force acknowledged the crash and pilot’s death in a statement Thursday.

Ukraine used the jets for the first time in combat to shoot down Russian missiles during the strikes this week, according to President Volodymyr Zelensky.

The Ukrainian Air Force said Mes, was killed in combat while helping repel the missile attack Monday. The General Staff of Ukraine’s armed forces said contact had been lost with the jet while it was approaching its next target.

A person close to the Ukrainian military said the cause of the crash was unknown and an investigation was under way. The person described Mes as a hero who successfully shot down multiple Russian missiles on Monday before the crash.

Mes, call sign “Moonfish,” was one of Kyiv’s first pilots to be trained on the F-16. He was one of the better known Ukrainian pilots, appearing frequently in the media and visiting Washington to lobby the U.S. to send Ukraine the jet fighters.

Mes met personally with lawmakers on Capitol Hill, including in 2022 with then-Rep. Adam Kinzinger (R., Ill.).

Mes often appeared with another prominent Ukrainian pilot, Andriy Pilshchykov, call sign “Juice,” who died in a training accident on Aug. 25, 2023. Two other pilots were killed in that incident, a midair collision.
The news that one of Ukraine’s few F-16s has been destroyed, and one of its most well-known pilots killed, is a major blow to Kyiv, which had pleaded for the jets for months before President Biden gave the green light for European countries to transfer the aircraft last year.

Kyiv hopes the advanced Western aircraft will give its forces an edge on the battlefield, particularly to shoot down incoming Russian missiles and help protect troops on the front lines. But the F-16s, many of which are secondhand and have decades of flying time already, are vulnerable to Russian air defense missiles and present a high-value target for Moscow’s forces.

U.S. officials also have warned about the dangers of sending pilots inexperienced on F-16s into combat. While Mes and other Ukrainian pilots now flying the F-16 are skilled in flying Soviet jets against the Russians, they went through an accelerated training course to learn to operate the American jets.

A newly minted American F-16 pilot typically wouldn’t fly in combat for many months after completing their training, spending additional time flying in-country with their unit.

A second U.S. official noted that the training curriculum for Ukrainian F-16s was “not standard,” noting that the program was focused on specific missions they would likely face in combat. “There’s still, very frankly, risk there,” the official said.

Kyiv hopes to have more Ukrainian pilots on the battlefield flying F-16s in the near future. A number of pilots are undergoing training at sites in Europe and the U.S.

Popular Pro-Kremlin military analysts and Telegram channels claimed that the plane was destroyed on the ground during Russia’s Monday missile attack. The Ukrainian military described the attack, which involved 127 missiles and 109 strike drones, as the biggest since the war’s initial days.

Zelensky announced Aug. 4 that the first of 80 promised F-16s had arrived in Ukraine. The Ukrainian Air Force didn’t provide numbers, but another U.S. official said six aircraft had arrived and Ukraine has six pilots trained to fly them. Denmark, the Netherlands, Belgium and Norway have said they would provide the aircraft.