Of tails and turbulence
Here's an article about B-52s losing their tails due to turbulence. It seems that was a problem with that plane, especially the D models. There doesn't seem to be any similar history with Airbus airliners but corrosion, metal fatique, or improper maintenance could've been factors.
Here's a good picture of vortices coming off the wingtips of a Bae 146 airliner in landing configuration. The vortices thrown by a 747 would be many times more powerful.
Here's a good advisory on wake turbulence.
Here's another good picture of vortices from a business jet. Here's a really cool picture of vortices from a C-130 that's ejecting flares.