(Image credit: General Staff of the Armed Forces of Ukraine) Ukrainian FP-1 drones struck the Gazprom Neft oil refinery in Omsk, Siberia, on July 6 after flying roughly 2,500 km over more than 12 hours, halting operations at Russia's largest gasoline producer, according to a report from UK pub The Telegraph . It was the longest-range Ukrainian drone strike of the war, carried out by an aircraft built around a plywood load-bearing structure, foam wings, and a two-cylinder piston engine, at an estimated cost of $55,000 per unit. Despite its lightweight structure, the drone managed to cause some pretty severe damage, setting fire to the CDU-10 crude distillation unit per Reuters , which handles 24,580 metric tons of crude per day and accounts for around 38% of the plant's processing capacity. A second unit, CDU-11, responsible for a further 37%, was shut down after network links vital to its operation were damaged.…