A gas turbine engine, a fan section for a gas turbine engine, and a method for assembling a fan section of a gas turbine engine are disclosed. The fan section may include a fan hub having a slot, a spinner having a castellated spinner seal, a fan blade including an airfoil extending from a root to a tip, wherein the airfoil has a leading edge and the root is received in the slot, and a platform secured to the fan hub and arranged between adjacent fan blades. The fan section may further include a flap seal having a base secured to a side of the platform, and a flap integral with and extending from the base portion and canted toward the root and engaging the blade, the seal trimmed back from the leading edge of the airfoil.