Decision-Aiding and Optimization for Vertical Navigation of Long-Haul Aircraft

<p>Most decisions made in the cockpit are related to safety and have therefore been proceduralized in order to reduce risk. There are very few which are made on the basis of a value metric such as economic cost. One which can be shown to be value based however is the selection of a flight profile. Fuel consumption and flight time both have a substantial effect on aircraft operating cost but they cannot be minimized simultaneously. In addition winds turbulence and performance vary widely with altitude and time. These factors make it important and difficult for pilots to (a) evaluate the outcomes associated with a particular trajectory before it is flown and (b) decide among possible trajectories. The two elements of this problem considered here are: (1) determining what constitutes optimality and (2) finding optimal trajectories. Pilots and dispatchers from major u.s. airlines were surveyed to determine which attributes of the outcome of a flight they considered the most important. Avoiding turbulence-for passenger comfort-topped the list of items which were not safety related. Pilots' decision making about the selection of flight profile on the basis of flight time fuel burn and exposure to turbulence was then observed. Of the several behavioral and prescriptive decision models invoked to explain the pilots' choices utility maximization is shown to best reproduce the pilots' decisions. After considering more traditional methods for optimizing trajectories a novel method is developed using a genetic algorithm (GA) operating on a discrete representation of the trajectory search space. The representation is a sequence of command altitudes and was chosen to be compatible with the constraints imposed by Air Traffic Control and with the training given to pilots. Since trajectory evaluation for the GA is performed holistically a wide class of objective functions can be optimized easily.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p><br>