Keeping a 1.5-year-old (18 months) occupied on a plane requires a "multi-sensory" approach because their attention span is typically only 5-10 minutes per activity. The most effective strategy is the "Wrapped Gift" method: wrap small, inexpensive new toys (like a plastic animal, a chunky car, or a board book) in several layers of paper. The act of unwrapping is an activity in itself. Window clings are another favorite; they are mess-free and can be stuck and re-stuck to the window or tray table. "Quiet books" with zippers and buttons, or blue painter's tape, which can be stuck to the seat and peeled off safely, provide great fine-motor distraction. Avoid toys with many tiny pieces or anything that makes loud electronic noises. Finally, never underestimate the power of a "snack tackle box"—a container with different compartments filled with varied textures (cheerios, dried fruit, crackers)—which turns eating into a sorting game that can buy you 20-30 minutes of precious silence.