Aircraft services group BBA Aviation said it has been outperforming the market during the first six months of the year and expects to continue doing so in the second half despite volatile markets."Conditions in our key markets have been relatively stable since the Interim Management Statement issued on 30 April 2009 and trading has been solid, assisted by our proactive management of the cost base," BBA said.The firm said it was continuing to successfully reduce its debts, which will help it benefit from an economic recovery when it comes.