Power systems group Rolls-Royce didn't give much away in its first-quarter interim management statement on Friday but reassured that trading since the start of the year has been consistent with previous guidance.For the year ending December 31st 2012, the group continues to expect "good growth" in underlying revenue and profit with cash flow around break-even as it invests in future growth.This growth is expected even when excluding the impact of last year's €3.4bn acquisition of German industrial group Tognum, jointly owned with Daimler, and the Rolls-Royce's proposed sale of its 32.5% shareholding in International Aero Engines."Rolls-Royce continues to invest across the Group in technology, capability and facilities to deliver on our current commitments, to improve productivity and to create opportunities for future growth," the statement said.The group said that it has achieved some "important milestones" since it announced its 2011 results in February, including the first flight of the Trent XWB engine on board an Airbus A380 flying test bed, and the opening of a new manufacturing and training facility in Singapore.BC