Preliminary development and flight trials of a cruise altitude and speed optimization decision support tool

Abstract

A cruise altitude and speed optimization decision support tool, based on the concept of a minimum cost altitude tunnel, was developed to aid flight crew and dispatcher situational awareness and decision-making in vertical trajectory planning in order to reduce fuel and time costs. As the optimal altitude for an aircraft changes with speed, weight, outside air temperature, and winds, flight crew decision-making can benefit from the calculation and display of the relative flight costs of possible trajectories. The concept of a minimum cost tunnel is introduced, and the decision support tool is presented. Four preliminary flight trials were conducted with a Boeing 777-200 and prototype decision support tool. The preliminary flight trials suggest that the decision support tool is useful and improves situational awareness and coordination between dispatcher and flight crew. The initial flight trials also indicated that flight crews would benefit from higher quality turbulence information, including synchronization of the turbulence information available to flight crews and dispatchers. The largest fuel savings observed for a flight from the preliminary flight trials was over 3800 lbs. Additionally, the flight trials suggest that the minimum cost tunnel would even be useful as a static image included as part of the flight plan to provide situational awareness and facilitate coordination with dispatchers.