Questor share tip: Rolls-Royce a hold on new engine orders These orders are underpinning the money Rolls spent on the next generation of engines. During 2012 the company invested £919m on research and development to improve fuel efficiency. That investment is now bearing fruit. Analysts estimate that the Trent XWB is likely to become Rolls's biggest engine programme over the coming decades, making up about half of the engine group's deliveries in the next five years. In addition to Japan Airlines, budget carriers such as easyJet, Ryanair and Jet2 are all thought to be in the process of ordering new aircraft as they seek to drive down prices, so it seems likely that the jets they are considering include those powered by the Trent XWB. The one-off engine orders are only the start. Once in the air the engines generate recurring revenue through service contracts as every part of the engine's data is monitored while it is in flight. The idea of this is that Rolls know what parts are needed where before the jet even lands. At the interim stage Rolls announced results that beat expectations. Analysts upgraded full-year forecasts and now expect adjusted pre-tax profits of £1.87bn, giving earnings per share of 70.7p, from revenue up 27pc to £15.5bn. There is one spanner in the works, that of bribery allegations to secure engine orders in Asia and China. These investigations are ongoing and information has been handed over to the Serious Fraud Office. The investigation is a concern, but the opportunity Rolls has to increase profits from making its production of the Trent XWB more efficient should outweigh this. The shares, having fallen more than 6pc from highs in May, are currently trading at 15.8 times forecast earnings, down to 13.7 times next year. They offer a forecast dividend yield of 2pc that is set to increase by 10pc for the next three years.