United Airlines has always been the airline with the dirty planes, at least as long as I can remember. I've often taken flights with sticky armrests, seat pockets filled with crumbs and the general stench of uncleanliness.

The airline had recently been ranked last in class in a JD Powers customer satisfaction survey. A combination of sloppy passengers, increasing delays and decreasing budgets had forced the airline to put cleaning their planes on a low priority.

That survey forced the airline to start paying more attention to its planes, especially in this economic climate, you don't want to be listed last on any kind or survey.

One of the big changes United made was in the way it tackled how aircraft are cleaned - a new process was implemented, and is making its way to all United Airlines destination cities. The first change was to clean the interior more often. In the past, the airline found it perfectly acceptable to wait 18 months for each "heavy cleaning", when 30 days is the industry norm. The new schedule calls for a major cleaning every 30 days on domestic aircraft, and 15 days on long haul planes.

The changes are starting to pay off - 40% fewer customers now complain about dirty planes.

In an in-depth article posted by the Chicago Tribune, the reporter was allowed to get up close and personal with the cleaning crew tackling a United 747 that arrived from Hong Kong.

The photos show the kind of damage passengers make when they are stuck inside a metal tube for 16 hours; magazines and other junk is thrown all over the place, apparently passengers feel it is perfectly acceptable to be a bit of a pig when someone else has to clean up their mess. The article also has a gallery of photos showing just how much work is involved in getting a plane ready for a new load of passengers.