Emergency Landing Automation Aids: An Evaluation Inspired by US Airways Flight 1549

Abstract

The Hudson River emergency landing of US Airways Flight 1549 inspired aviation enthusiasts and citizens alike. The pilot's skill and composure were exceptional, clearly contributing to one of the most successful aircraft water ditchings possible. As we prepare for transition to a next-generation air transportation system, we are developing new technologies both to increase system capacity and efficiency and improve safety levels. This paper describes the practical application of an adaptive flight planning automation aid to the specific US Airways loss-of-thrust situation, demonstrating how this technology, if available, could have enabled a safe return to a LaGuardia runway. First, the adaptive flight planning architecture and its evolution are summarized, followed by an analysis of the Flight 1549 cockpit data recording time histories to identify pertinent features for our analysis. The adaptive flight planner was tasked with identifying emergency no-thrust landing plans for the A320 at a series of different delay times after the dual bird strike incident occurred. Our results show that LaGuardia airport runways were reachable so long as the approach is initiated within approximately sixteen seconds after the dual bird strike incident. This result is consistent with accident docket data published by the NTSB. Our results further illustrate how chances of a safe runway landing decrease as a function of delay, in this case due to being forced to land on a runway with suboptimal wind conditions, or ultimately being forced into a water ditch situation that may not always have the positive result of Flight 1549. Our adaptive flight planning software, written in C, computes landing flight plans in under a second on a single-core PC with no changes in this work from a pre-2009 implementation beyond A320 glide parameters. With sub-second real-time response, an emergency landing plan can be presented to the pilot just as he/she is beginning to consider options, maximizing the efficiency with which the plan can be executed. Further, with datalink capability, emergency flight plan information can be disseminated throughout the local air traffic network to maximize coordination efficiency.