He joined the Ukrainian Airmobile Forces in late summer 2014, after the War in Donbas began. Zubkov became a deputy fire support company commander in the new 90th Separate Airborne Battalion of the 81st Airmobile Brigade. He fought in the Second Battle of Donetsk Airport from late December 2014. On January 18, 2015, Zubkov participated in the Ukrainian assault to relieve troops trapped in the airport. He led the defense against counterattacks and called in artillery on himself. On January 19 he was wounded, but remained in the new terminal with his men. He helped evacuate wounded soldiers. On the next day, Zubkov was killed while covering his unit's retreat when separatists collapsed the second floor onto them. He was buried in Derazhnia on April 30, after his body was found in the rubble.