Patent ID: 9081935
Filing Date: 2015-07-14
Classification: G01C,G06F,G08G

Abstract:
1. A method of establishing availability of an Extended Operations (ETOPS) flight path for a predefined two-engine aircraft including a first engine and a second engine, the method comprising: calculating a probability of a dual independent engine shutdown sequence of the predefined two-engine aircraft for each of a climb phase, a plurality of cruise phases including an ETOPS phase, and a descent phase into which the ETOPS flight is divisible, the dual independent engine shutdown sequence being composed of a sequence of events that for each phase includes events having respective, conditional probabilities a product of which is the probability of the shutdown sequence for the phase, the conditional probability for the ETOPS phase being specific to an ETOPS rule time for the ETOPS flight path; calculating a risk of the dual independent engine shutdown sequence during the ETOPS flight as a function of a sum of the probabilities for the phases; and establishing availability of the ETOPS flight path that the predefined two-engine aircraft will follow, the availability being established based on the risk and a preexisting baseline, wherein the ETOPS flight includes takeoff from an origin airport and touchdown at a destination airport, and the dual independent engine shutdown sequence is composed of a sequence of events that for each phase includes in sequence, a first event of shutdown of the first engine during the ETOPS flight, a second event of a non-restartable shutdown of the second engine before touchdown at the destination airport or an alternate airport, and a third event of an inability of the first engine to restart, and wherein the method further comprises calculating the conditional probability of the third event for each phase as the ratio of a non-restartable engine shutdown rate to total engine shutdown rate for the phase.