Lufthansa B744 at Frankfurt on Jul 31st 2014, stuck flaps

A Lufthansa Boeing 747-400, registration D-ABVT performing flight LH-500 from Frankfurt/Main (Germany) to Rio de Janeiro,RJ (Brazil), was climbing out of Frankfurt when the crew stopped the climb at FL110 for about 10 minutes, then accelerated and continued the climb to FL200, then entered a hold for about 25 minutes. The crew decided to return to Frankfurt reporting problems with the flaps. The aircraft descended to FL090, then maintaining low speed (about 290 knots over ground) climbed to FL150 and entered another hold. The aircraft subsequently positioned for a high speed approach to runway 25L touching down on the runway at about 200 knots over ground. The aircraft rolled out safely, emergency services responded and checked the brakes.

A passenger reported that some time after departure the captain announced they could not fully retract the flaps, which wasn't a problem at all except for burning too much fuel to reach Brazil, they would no dump fuel and return to Frankfurt. The passenger reported no further announcements were made, the passenger was puzzled about the huge number of emergency vehicles attending the aircraft after landing especially as per the captain's announcement the landing wasn't a problem.