Frankfurt, August 12, 2019, SPA -- A Lufthansa Boeing 747-400 bound for Shanghai with 370 passengers on board was forced to turn back to Frankfurt shortly after take-off due to an engine failure, a spokesman said on Monday. There was no acute emergency, the spokesman told dpa. The pilots had decided to return Frankfurt airport late Sunday "as a precaution." The spokesman added that one of the engines had experienced a "type of backfiring" shortly after take-off, which the other three working engines would have been able to replace "effortlessly." This type of backfiring is rare but not unheard of, the spokesman said. The four-engined aircraft landed normally. The passengers were due to fly to Shanghai at 11:30 am (0930 GMT) on Monday on a different aircraft. --SPA 16:01 LOCAL TIME 13:01 GMT 0012 www.spa.gov.sa/w1155098