It's hard for me to believe the economics involved here: ferrying a 757 from the US to HKG and back in order to perform maintenance. It's not as if HKG is a third-world location - could airplane maintenance labor really be that much cheaper there than in the US that it justifies ferrying a 757 half way around the world and back in terms of fuel and crew hours? I guess it must make financial sense, otherwise they wouldn't do it.

I understand how it makes sense for the 777's, as they're flying there anyway and can just be rotated in and out of revenue service, but 757's?