The term 'Train to a Plane' can be solved by the four-letter word 'TRAM'. A TRAM is a type of public transport vehicle, usually powered by electricity, which runs on tracks along public roads. It is similar to a train, but typically smaller and more closely associated with urban areas. Trams are often used to connect airports to nearby cities, allowing passengers to travel from the airport to the city center without having to take a taxi or bus.