Rolls-Royce has hit back at claims it cut corners on quality control requirements. Two former employees of the engine maker, Thomas McArtor and Keith Ramsey, made the allegations in a US lawsuit in which they accused the company of routinely using parts designated as 'scrap only'.The pair is trying to get the court to lift an order that stops them from releasing information which they say reveals details of what the firm kept hidden. They allege the firm concealed internal records of defects in engines sold to clients. Rolls-Royce has denied the claims, saying it will "defend itself vigorously". The company said a US district Judge, William T Lawrence, had already thrown out some of the allegations. "Judge Lawrence did not find that Rolls-Royce engaged in any wrongdoing, failed to follow its quality system, concealed anything from the US government or even that a jury is entitled to hear the allegations," the firm said."Any and all facts of the case will be presented in court, where we are confident it will be found the lawsuit is without merit."Rolls Royce last week apologised for the mid-air failure of its Trent 900 engines on a Qantas plane in November 2010. The company issued a statement after Australian's transport safety regulator blamed the failure on a fatigue crack in an oil feed pipe in the engine. RD