The Q-statistic is the answer to the question: "Suppose that a person chose a flight completely at random from among the set of interest (e.g., scheduled UK domestic jet flights in the 1990s). What is the probability that he would not survive the flight?" In this section, we are speaking of death in an aviation accident, and not from terrorism or natural causes. A flight is a non-stop trip; a journey that involves one intermediate stop would entail two flights. The Q-statistic - which is essentially death risk per flight - assumes that there are N flights that can be indexed as (1, 2, 3,. . .,N). We define as the fraction of passengers on flight who do not survive it. If the flight lands safely, then ; if it crashes and no one survives, then ; if it crashes and 20% of the passengers perish, then . To determine the Q-statistic, we note that each of the N flights has the same chance of 1/N of being selected at random. Given that flight i was selected, the traveler's conditional death risk is xi. One way of dying because of the "flight lottery" would be to choose flight 1 at