The Air France/KLM-led Skyteam alliance has reached an agreement with Heathrow airport to switch all flights to Terminal 4 from spring 2008. At present, the Skyteam members’ flights are split between Terminals 2, 3 and 4.

Reports in the French national press say that the plan is to have Air France and KLM short-haul flights feeding flights of fellow US members Delta, Continental and Northwest. The latter currently operate a number of routes from Gatwick such as Atlanta, Houston, New York and Minneapolis.

But Air France and KLM are expected to provide these US carriers with slots to enable them to transfer some routes to Heathrow.

Besides the Skyteam members, T4 will also become to home to what’s termed “non aligned” airlines, ie those carriers who are not part of an airline alliance.

Although Virgin Atlantic will be staying at T3 it means airlines like Malaysian, Kuwait, Royal Brunei, China Eastern and so on will switch to T4. However T4 will have a drawback in that public transport access won’t be as good as it is now. Rail services to this terminal will be downgraded once T5 (the new home for British Airways) opens next April.

The Heathrow Express which operates to Heathrow Central (the station serving T1, 2 and 3) will be extended to T5 instead of T4. So passengers bound for T4 will have to change at Heathrow Central and wait for a shuttle train link.

It will be more inconvenient for passengers planning to use the Piccadilly Underground line to access Heathrow T4. The current service, which sees a train calling at T4 every five minutes or so, is expected to be cut to a 15-minute frequency.

From April next year, BAA (the operator of Heathrow) envisages there will be 12 Piccadilly Line trains an hour to Heathrow Central, eight to T5 and just four using the separate loop to T4.