A NASA research program has led to a U.S. patent for a system designed to warn pilots when energy levels on approach stray outside normal ranges. Awarded in July, the patent is for a system and related software designed to analyze “kinetic and potential energy” on approach and takeoff to determine if the aircraft “will be put in an anomalous configuration” when joining a stable approach or takeoff path. Engineers working on the NASA program were granted the “Energy Index for Aircraft Maneuvers” patent after developing a method for monitoring an airplane’s energy state. Landing accidents are often attributed to unstable approaches, NASA said. Data taken from the monitoring system could be used by airlines post-flight to track approach and takeoff performance or developed further to provide a real-time warning system for pilots, researchers said.