Lufthansa no longer flies the 150 km from Frankfurt to Cologne, and instead reserves an entire car on thirteen 300km/h high-speed trains a day in each direction for its international connecting passengers.

So if you're connecting to Cologne on Lufthansa, this is how you'll get there.

It's called AIRail, and Australian Business Traveller tested out the route this week.

Check-in is swift, efficient and airline-style at the glass-and-steel Frankfurt Airport Fernbahnhof (long-distance railway station).

The Fernbahnhof is part of the airport, connected by an walkway tube to the terminal.

You'll be given your airline-style boarding pass with an LH flight number to QKN, which is Cologne Hauptbahnhof (main railway station), rather than CGN, the Cologne-Bonn airport.

Check-in luggage is taken from you at check-in by friendly porters and returned to you once you reach Cologne.

You can even add your cabin carry-on from the plane to the luggage stack for the shorter journey, so you don't have to carry it on the train.

Then it's down the escalators and onto the 300 km/h ICE3 high-speed train -- no hiking through the airport, no extra security checks. Check the boards or ask the English-speaking staff to find out where to board the train closest to your seat.

57 minutes later, you're right in the centre of Cologne, looking out onto its famous Kölner Dom Cathedral, heading to your meeting or sipping on your first cold glass of the local Kölsch beer.

You'd be hard pressed to connect to a Cologne-bound flight and get into the centre of town from the airport in under an hour.

On the way, you'll be sitting in a comfortable 2-2 layout train car, with what we reckon is about 39 inches of seat pitch, the same as Australian domestic business class and a big improvement on the Eurobusiness "economy with a spare seat in the middle" Lufthansa offers on domestic flights.

There's a table big enough to use even the largest laptop and there's at-seat power available, plus wi-fi available, although you'll have to fork out €5 (about A$7).

When pressed on the pricing, Lufthansa's man in charge of the service was adamant that none of its passengers say they want wi-fi included, which we found pretty incredulous since the first thing many business travellers do when touching down after a 14-hour flight is get online, check their mail and catch up on the news.

Business Class passengers get a special cabin at the very end of the train, where you can look backwards and marvel at how fast you're whizzing through the German countryside on the way to Cologne, or watch the train's driver at work on the way to Frankfurt.

A choice of sandwiches (try the trio of salami, cheese and ham on dense, chewy German Vollkornbrot rye bread), drinks and chocolate bars are offered by English-speaking train crew.

All in all, AIRail is fantastic: comfortable, quick, connected, and convenient. With this service, and for this kind of distance -- or, frankly, even double this distance -- the train beats the plane every time.

We wish more destinations -- not just Cologne and Stuttgart -- were included in the AIRail network.