Fuel Burn and Emissions Reduction Potential of Low Power/Low Drag Approaches

Changing aircraft operational procedures is one strategy that can be used to reduce fuel burn and mitigate environmental impacts of aviation in relatively short timeframes with existing aircraft types. This study quantifies the fuel burn and emissions reduction potential of delayed deceleration approaches, where the aircraft is kept fast and in clean aerodynamic configuration for as long as possible during the approach phase of flight. This reduces the drag and thrust requirements and these procedures are therefore called Low Power/Low Drag approaches. Operational data is used to characterize approach profiles, together with their fuel burn and emissions properties correlated to airspeed and configuration for a selection of aircraft types. Aircraft that were observed to decelerate and configure flaps later in the approach had 30-40% lower fuel burn and carbon dioxide emissions below 10,000 ft compared to those that did not. Estimates of US system-wide fuel burn and emissions reduction potential from Low Power/Low Drag approaches are provided: if only 1% of the total operations used these approaches, savings across all operators would amount to 2.9 million US gallons ($5.8-11.6 million at $2-4/US gallon) of fuel and 28,000 metric tons of carbon dioxide emissions per year. A discussion is provided on the implementation barriers which need to be addressed if benefits are to be realized.