Hot air balloon
Balloons

As with other aircraft in the US, balloons must be registered (have an N-number), have an airworthiness certificate, and pass annual inspections. Balloons below a certain size (empty weight of less than 155 pounds or 70 kg including envelope, basket, burners and empty fuel tanks) can be used as an ultralight aircraft.
combination:two_responses, length_constraints:number_words[402]