I arrived at the airport (KSJC) today to give a Wings Program Flight Review.  My student had recently gotten a hangar at the airport and by chance it was located right next to mine.  It took all of 2 seconds to notice that the nose wheel tire seemed deflated down to about half full.  I asked the student when he last flew and he said it had been about 6 weeks.  I had previously had tires that lost air over a period of time, but never that much.  Still, I thought maybe it was possible, but I still