Over this past weekend Southwest airlines canceled 300 of their flights for inspection because of an emergency decompression that happen on one of their flights on Friday. Last friday a Southwest B-737 cabin ceiling ruptured in the cabin. The hole was a couple of feet long. So, basically what is a cabin decompression? Basically, its a lost of cabin pressure air. Depending on the altitude where the decompression happen, you may have between seconds ,or a minute to get oxygen before passing out. You may be wondering why Southwest is grounding a large portion of its fleet while other airlines are not. There are a lot of different models of the B-737. The first model was built in the late 60's. Today, the latest version is the B-737-800/900 series, or ng (next generation) Southwest airlines has the largest order of B-737 with some 100 models that are old. However, Southwest airlines have an unique style of flying in that they fly a lot of short legs in the B-737, and more so then most carriers.What this means is that they have more wear & tear on the airplane because of the constant climb & descent. These cycles in altitude put a lot of stress on the fuselage & may require a lot more maintenance inspections compared to other long haul flights. I don't know the maintenance cycle of Southwest airlines, but I do know that history shows if you put a lot of stress on an airplane you should inspect more frequently. Another similar decompression happened in 1989 with an Aloha Airlines flight that had fatalities.