A recent article describing 747 D-checks

http://www.aerosphere.com/Magazine/A...onautics.shtml

"A D check takes between 15,000 and 35,000 hrs. of labor, and can put aplane out of service for 15 to 30 days, or more. The total cost averages between $1 million and $2 million." "A typical D check is 70% labor and 30% material,"...

...Ready to Fly

After 56 days of inspections, checks, repairs, and maintenance, the aircraft is ready to leave the hangar and resume flying passengers and cargo. Only a small fraction of the maintenance operations have been mentioned here. But before flying again, the aircraft may be testflown by a special crew to ensure that all systems function properly. It is reassuring to consider briefly how much expertise and technology go into keeping the aircraft that you fly in mechanically sound. "

I can't seem to find information on the backlog. $1 - 2 million doesn't seem bad for a D check