Ukraine appears to have lost its first Lockheed Martin F-16 fighter jet, less than one month after the type entered service with the Ukrainian air force (UAF) in early August.

Although the exact circumstances remain unclear, the downing of the American-made craft appears to be connected to the wave of air attacks launched by Russia against Ukraine throughout the week.

The general staff of the Ukrainian armed forces confirmed the loss of an F-16 in a 29 August post on the social media site Telegram, which is popular in Ukraine and Russia.

Ukraine air force F-16 livery

Source: X/Volodymyr Zelensky

Ukraine has only received a small number of F-16 fighters thus far, although nearly 100 of the American-made jets have been pledged to Kyiv by Western backers in Europe

Kyiv claims a number of the multi-role fighters were dispatched to help defend against a Russian missile attack, supplementing ground-based air defences. The F-16s shot down four Russian cruise missiles, according to the defence ministry.

“During the approach to the next target, contact was lost with one of the planes,” the general staff says. “The plane crashed [and] the pilot died.”

A defence ministry investigation is underway into the cause of the crash. The message does not indicate if the single-engined fighter was shot down, experienced a mechanical failure or if pilot error was a factor.

The Ukrainian service of US government-funded news outlet Voice of America reports that friendly fire by Ukrainian air defence forces is also being considered as a possible cause.

Separately, the UAF confirmed in a 29 August Telegram post that fighter pilot Lieutenant Colonel Oleksii Mes was killed on 26 August “while repelling a Russian massive, combined missile and air strike”.

Mes had appeared frequently in Western media since the war began, where he went by his call sign “Moonfish”. He is known to have been amongst the Ukrainian fighter pilots being trained to operate the F-16, after previously flying Soviet-origin Mikoyan MiG family of fighters in the UAF.

“Oleksii saved Ukrainians from deadly Russian missiles… unfortunately, at the cost of his own life,” the UAF says. The service claims he destroyed three cruise missiles and a one-way unmanned aerial vehicle during his final sortie.

The notice from the UAF does not offer any specific details about how the events transpired. Mes was posthumously promoted to the rank of Colonel. 

Ukrainian president Volodymyr Zelensky earlier in the week confirmed that F-16s were used in repelling the Russian air attack on 26 August. Russia has fired waves of missiles and drones against Ukraine in recent days, as Kyiv’s forces continue to hold Russian territory in the border region of Kursk.

The UAF claims to have identified 236 individual weapons systems during the 26 August attack, including 109 Iranian-supplied Shahed-131/136 UAVs and 127 guided missiles. Amongst the precision munitions were 10 of Russia’s newest Kh-69 air-launched cruise missiles, which Kyiv says were deployed by Sukhoi Su-34 strike fighters and Su-57 low-observable fighters operating from Russian airspace.

Tupolev Tu-95MS strategic bombers are also deployed 77 Kh-101 air-launched cruise missiles, according to Kyiv.

“All available weapons and equipment were involved in repelling the air attack,” the UAF says, specifically noting aviation, anti-aircraft missile forces and electronic warfare units.

Dozens of Russian weapons were also launched in subsequent bombardments on 27 August and 29 August.