Mystery solved: Keesler Air Force Base team solves riddle of illness aboard C-130s 09 Apr 2015 WESLEY MULLER
"BILOXI -- For years, a strange problem with the U.S. Air Force's C-130 aircraft had pilots and crews reporting sickness, discomfort and, in some cases, excruciating pain after routine flight missions. The phenomenon remained a mystery until February, when a handful of reservists at Keesler Air Force Base took the initiative to solve the mystery. They made a tiny discovery that's affecting airplanes worldwide.
The problem was with the pressurization system on the C-130 Hercules -- the longest-produced and perhaps most-popular aircraft in military history...."