[1] Airline accident fatalities trended downward during the rollout of air traffic control technology in the '60s and '70s, but in recent years have remained flat. (Accident statistics reflect accidents due to all causes—pilot error, airborne equipment failure, and misunderstood communications, as well as deficiencies in the air traffic control system. Changes in air traffic control technology or avionics can address only some of these causes.) Meanwhile, worldwide air traffic is expected to grow dramatically over the next two decades. Unless the fatality rate can be pushed off of its plateau to head down toward zero, the increased traffic may lead to an unacceptable number of fatal accidents. If the system does not change significantly, by the year 2015 there could be a major aviation accident every seven to 10 days, according to one projection.