Effectiveness of adaptive flight planning in the occurrence of total loss of thrust due to bird strike.

摘要

As of today, more than 96 percent of air travelers are transported on twin-engine jets. Although contemporary twin-engine jets are more reliable and efficient than yesterday's three- and four-engine jets, they have reduced engine redundancy. A statistical analysis of the FAA Wildlife Strike Database shows that contemporary twin-engine jets are approximately 15 times more likely to undergo total loss of thrust in the event of a bird strike compared to yesterday's three- and four-engine jets. To address the total-loss-of-thrust emergency, quick reference handbooks are designed to enable speedy and successful recovery of at least one engine. Airliner type-rating programs assume that total loss of thrust culminates in at least one engine recovery. If an engine restart cannot be achieved in a real-life emergency, airline pilots are left with virtually no guidance on how to manage the emergency situation.;This dissertation hypothesizes that "an adaptive flight planner can significantly increase the odds of safe landing in the occurrence of total loss of thrust". The objective is to test the research hypothesis through a designed experiment. To construct the experimental conditions, the FAA Wildlife Strike Database is statistically analyzed, and the most hazardous bird strike conditions are identified in terms of engine failure. The findings show that engine failure due to bird strike is significantly most likely to occur during the initial climb out at a low altitude (i.e. below 5,000 ft AGL). Using the findings, five realistic bird strike scenarios are generated to be simulated in the designed experiment.;Next, an adaptive flight planner is architecturally designed for the two best-selling commercial jets: the Airbus A320-200 and Boeing 737-800. The function of the adaptive flight planner is to compute the optimum landing trajectory in the occurrence of total loss of thrust, and then to guide the flight crew over the optimum trajectory using standard oral ATC commands that are easy to interpret. However, the idea of engines-out landing trajectory optimization has not been developed for commercial jets due to the unavailability of aircraft-specific aerodynamic-coefficient data. To fill in this gap, a kinematic approach is adopted to develop a trajectory optimization algorithm, which is based on pure motion characteristics without making reference to the aerodynamic forces involved. The kinematic approach requires minimal amount of aircraft-specific aerodynamic data that can be effortlessly collected in a full flight simulator. Using the kinematic method, the adaptive flight planner is architecturally designed for the A320-200 and 737-800 aircraft, and its accuracy is verified through flight simulation tests.;Subsequently, the designed experiment is conducted with 12 type-rated pilots. Five total-loss-of-thrust scenarios are simulated in the A320-200 and 737-800 full flight simulators. For each scenario, the adaptive flight planning architecture is used to compute the optimum landing trajectory and the ATC commands for guiding the pilots over the optimum trajectory. Every scenario is simulated twice with each of the 12 pilots in command. First, the pilot in command is asked to attempt engines-out landing on a runway of his/ her own preference. Second, the pilot in command is guided with the air traffic control commands over the optimum landing trajectory. The outcomes are recorded as "success" if the pilot achieves safe touchdown on a runway, and "failure" otherwise. The results are analyzed using a generalized linear mixed model approach. The findings present strong evidence in favor of the research hypothesis that the adaptive flight planner can significantly increase the probability of safe touchdown in the occurrence of total loss of thrust. The results are synthesized into design recommendations which summarize the proposed application of the adaptive flight planning architecture.;This study is the first of its type to address commercial jets, and the findings can open the door for how commercial aircraft manufacturers address the total-loss-of-thrust hazard through innovative cockpit technologies.