The RB207 had also suffered difficulties and delays , since Rolls-Royce was concentrating its efforts on the development of another jet engine , the RB211 , for the Lockheed L-1011 and Rolls-Royce entering into administration due to bankruptcy in 1971 .
The RB207 had also had design problems and delays , since Rolls-Royce was concentrating on designing a different jet engine , the RB211 , for the Lockheed L-1011 The A300B was smaller but lighter than its American rivals .