But Juice and another Ukrainian pilot, whose call sign is “Nomad,” said the learning curve isn’t as substantial as it’s often made out to be. Nomad, who is in the United States as part of a training program, said it would probably take Ukrainians about two weeks to learn the nuances of the U.S.-made F-series planes. Many of the pilots already speak English and have participated in joint exercises with the U.S. Air Force, so they’re familiar with the terminology of those planes’ systems, they said.