Payload Range Efficiencies, as Designed and in Practice – Are there any Lessons?

摘要

Following on from the previous work, a decade ago, by Nangia on Efficiency Parameters [1], this paper reviewsthe progress and more importantly relates the Payload Range Efficiencies as designed to what really happens inpractice. The payload-range diagrams are combined with the frequency data of the most common flights operated byUS airlines. The frequency data is obtained from the USA Bureau of Transportation Statistics flight database [2]. It hasbeen used to estimate typical payload and mission range of the most frequent flights in US from 2000 and 2017. Thederived diagrams serve as first-order approximations of the limited knowledge of the flight missions available. Typicaldiagrams are attached. Several examples illustrate and emphasize the issues. We also give some correlations toshow shortfalls in various classes of aircraft types. A major inference is that in practical operations, the aircraft areworking well below the design capabilities and efficiencies; in some cases very low efficiencies. The message is clearlyfor operators to be aware and positively seek / plan to improve the operations. Another idea is towards design of aircraftwith larger capacity but smaller ranges.