Ukrainian distinguishes between directional (specific, ongoing) and habitual (repetitive, general) actions through different verbs:
• Летіти (with лечу as its 1st person singular form) is used when referring to a specific instance or a continuous action (e.g., “I’m flying right now”).
• Літати is used to express habitual or repeated actions (e.g., “I fly regularly” or “I’m a frequent flyer”).
Thus, "Я лечу" suggests you are in the midst of a specific flight, while "Я літаю" would imply a general ability or regular activity of flying.