Ryanair observers may be somewhat puzzled at the appearance of the airline's sparkling new Boeing 737-800 jet on the Dublin to Stansted route. When the plane was delivered six weeks ago, the company's chief executive, Mr Michael O'Leary, vowed that because of the ongoing wrangle between himself and Aer Rianta, he would not use it in Dublin.

In brief, Aer Rianta has said it is increasing the amounts it charges per passenger to airlines. Ryanair argues that it should pay less per passenger, but promises to increase the number of new routes - and therefore the volume of passengers and revenue for Aer Rianta. Mr O'Leary has said the company is planning to offer Irish travellers several new Continental destinations direct from Dublin, but that until Aer Rianta and he can agree, these are suspended. The new plane, he added, would be used only on flights from Kerry and Knock to Britain.

But for several weeks now skywatchers have been reporting that Ryanair's new plane is indeed flying in and out of Dublin. This week, Ryanair confirmed this was the case, but described the journeys as "proving flights" - the test-runs used by new pilots.

The flights are, however, carrying up to 330 fare-paying passengers on board. Ryanair now says this plane will not be used in Dublin for long, and that when the summer schedule starts, it will be moved to Stansted for routes to the Continent only.