Originally Posted by geldap
This is nose wheel shimmy. First time it will be penned with an inspection and spin check - second or third time the nose wheels will be replaced which will cure the problem. It is very very common on 400s. I certainly would not escalate this as it is nothing and you would make yourself look pretty silly. I would think that it was put in the tech log once reported by cabin crew. The crew would not report this back to you as they have no reason to discuss the contents of the tech log with a punter - pilot or not.
Nose gear shimmy usually lasts a bit longer and often is not evident throughout the cabin. Maybe we can get an idea where the reporting person was seated?
Anyway, plane's still flying - a good thing with 747s - one of the best and safest designs around.