AiRail Service is offered by Deutsche Bahn AG in cooperation with Lufthansa German Airlines, American Airlines, and Emirates.

AiRail Service is currently offered between Stuttgart Main Station (Hauptbahnhof) and Frankfurt am Main's Frankfurt International Airport (Long Distance Train Station) and between Cologne Main Station and Frankfurt am Main.

It enables all passengers between Stuttgart/Cologne and Frankfurt to check in their baggage at the stations and use the ICE high speed train service to Frankfurt (first class between Stuttgart and Frankfurt, second class between Cologne and Frankfurt for economy class passengers, first class for business and first class passengers) without having to carry their baggage themselves.

All passengers receive their boarding passes for connecting flights from Frankfurt immediately at the check in counters in Cologne or Stuttgart.

AiRail Service uses the high speed lines between Siegburg and Frankfurt (maximum speed of 300 km/h) and between Stuttgart and Mannheim (maximum speed of 250 km/h), rendering the train service faster and more reliable than air transport on the same route.

AiRail Service was established some decades ago, when Deutsche Bundesbahn (now Deutsche Bahn AG) established a direct connection between Düsseldorf and Frankfurt Airport using the famous DB 403 "Donald Duck" EMU with tilting technology in Lufthansa livery. In the 1990s they established the Stuttgart-Frankfurt connection after the high speed train line between Stuttgart and Mannheim was opened. Both services were closed due to high cost some years later. In 2000 they re-established the service between Stuttgart and Frankfurt, now using only one car in regular ICE service. In December 2002 Lufthansa and Deutsche Bahn opened another service between Cologne and Frankfurt.