A Truck with a Luggage Trolley

Lea works as a dispatcher at the airport. She tells aeroplanes when they can land and when they can take off. Leo and Lifty have built a belt loader. The belt loader's working, but it's empty. Where's the baggage? The robots are taking cargo from the plane and creating a huge heap of suitcases just off the plane. But how can they get it all into the airport? Leo builds a baggage truck for transporting luggage.