The dose of ionizing radiation received by passengers and crew members traveling on commercial airlines which transport radioisotopes is of interest to all persons who travel the airways frequently. Tariff regulations permit the air transport of 40 units of radioactive materials where one unit represents a quantity of radioisotopes which when packaged delivers a dose rate of one mr/hr at a distance of one meter from the center of the package. Using five different types of commercial aircraft, shipments of radioisotopes were simulated and dose levels determined at various locations in the aircraft under conditions normal to commercial travel. The survey indicates that the tariff regulations should be amended giving consideration to the type of aircraft involved.