Implementation of Fuel-Saving Relaxed Climb Procedure

In the previous works, the author investigated an optimal climb trajectory by reducing thrust near the top of climb utilizing vertical speed mode. While the prior study demonstrated the potential for fuel savings through numerical simulations, it only considered a limited flight environment. This paper delves deeper, aiming to implement the proposed climb method in the real world. Specifically, this paper presents three contributions. Firstly, to mitigate the potential concern of flight safety and pilot workload, an enhanced pilot procedure employing maximum cruise thrust setting instead of vertical speed mode is proposed. Secondly, the influence of various flight parameters, such as wind, air temperature, and the selection of cruising altitude, is investigated to ascertain the applicability of the proposed climb method in the real world. Thirdly, the proposed climb method is evaluated using full-flight simulator experiments involving multiple aircraft types, conducted in collaboration with a Japanese aircraft operator. The expected impact of the proposed climb procedure is revealed in terms of fuel savings and pilot workload. According to the findings, the proposed procedure has the potential to yield up to 100 lb of fuel per climb, with negligible implications for flight safety and pilot workload.