Fig. 3: Hourly fuel consumption and emission relative error (RE, %) found using the ALTFEM and the ICAO and the yearly fuel consumption and emission RE values found using the ALTFEM and NG at the 237 airports.

(The size of the circle indicates the range of the LTO numbers at the airport; and the mean relative error (MRE) for different pollutants is labeled as a different color at the top of the graph).