Report on Decompression Illness, Diving Fatalities - Divers Alert ...

4.7 Flying After DivingIf a diver was exposed to a secondary decompression stress fromaltitude change within 48 hours of his or her last dive, the altitudeexposure was considered as part of the PDE dive series. Becausemost altitude exposures occur with flying, this exposure is referredto as “flying after diving” (FAD), even though it also can be causedby mountain travel. Most altitude exposures in our sample occurredin commercial airliners that maintain a cabin pressure equivalent tonot more than 8,000 feet (240 meters) above sea level (approximately77 percent of the atmospheric pressure at sea level). Flying innon-pressurized fixed-wing aircraft or helicopters after diving wasuncommon. Because most dive computers do not record altitude(only recent Cochran computers do), the pressure-time profile of thealtitude exposure was unknown.None44.7%UnpressurizedAircraft 0.4%Not <strong>Report</strong>ed29.0%Fig 84Altitude exposureafter diving.Helicopter0.1%PressurizedAircraft18.3%Figure 84 shows that 18 percent of all participants reported havingflown in commercial airliners within 48 hours of their last dive.However, when the PDE sample was narrowed to exclude dive professionalswho presumably dive where they live and divers fromthe United Kingdom who presumably drive to the dive site, the estimatedPDE percentage of altitude exposure after diving (within 48hours) increased to 47 percent. Figure 85 also shows that in that narrowedsample of U.S. recreational divers, 1 percent flew non-pressurizedairplanes and 1 percent reported ground travel to the mountains.None53.0%Ground Travel7.6%UnpressurizedAircraft1.0%Helicopter0.1%PressurizedAircraft44.6%Ground Travel1.2%Fig 85Estimatedpercentageof altitudeexposure in U.S.recreational divers.DAN’s <strong>Report</strong> on Decompression Illness, Diving Fatalities and Project Dive Exploration: 2003 Edition 79