Oil Leaks & Vibration
Anonybocks
My guess would be that the external oil leaks being experienced by Singapore are probably due to vibrations where the tube fastening nuts are vibrating loose. Rolls Royce, in proceeding through the various Mod revisions probably made changes to the frame that support the HP/IP rear bearings to both strengthen and stiffen it and to also eliminate the infamous stub pipe that broke on the Qantas A-380. In doing so, these changes were made "on the fly," so to speak. However, all the piping on the outside of the engine can react differently when changes are made to the engine structure. Not only that, this maze of tubing is the most difficult to wring out in terms of vibrations. There are all sorts of "tricks" that can be done to stop tubing from vibrating, but, prediction it is one thing verses in flight experience. It is easily fixed once it is determined which tube (and the location where) is vibrating. I think that is what is happening now. Singapore has more A-380's in the air on any given day, perhaps at times, 2/3 of the entire A-380 fleet. So they are going to be the flight leaders in experiencing this annoying problem.