Aviation services provider BBA Aviation said group revenue was flat, in line with company expectations, as it issued an upbeat assessment for the rest of the year.In the first quarter to 31 March 2010, revenue was flat compared to the same time a year ago and increased 2% on an organic basis.Trading since the end of March has followed a similar trend to the first quarter of the year, although its European Flight Support businesses and ASIG US were affected by the recent closure of European airspace. BBA added that the recent closure of European airspace would only have a minor impact on its results.Commenting on the group's trading outlook for the rest of the year, chief executive Simon Pryce said, "The early signs of an emerging recovery in B&GA flying hours experienced in the last quarter of 2009 have continued into 2010." He added, "Our flight support businesses are already benefiting and our later-cycle aftermarket services and systems businesses should begin to see the impact of this in the second half."