The effects of flap extension time on the fuel burn of commercial aircraft

Abstract

Purpose This paper aims to investigate the effects of descent time spent with flaps extended on fuel burn (FB) and specific range for five different flight path angles (FPAs) ranging between 2.0° and 4.0° for a commercial aircraft. Design/methodology/approach A large data set of actual flight data (n = 475) of the same type of a frequently used commercial aircraft were investigated by using statistical methods. Findings The result of the comparison of the highest and the lowest FBs of flight profiles for each FPAs present that the fuel saving was achieved by keeping at as a high airspeed as possible and deploying flaps as late as possible, which is in line with the objective of delayed deceleration approaches. From analyzing the flight profiles, it was proven that delaying deceleration and also descending without flaps or with flap over a shorter time resulted in less FB of 101.1, 70.9 and 94.9 kg for FPA 2.5°, FPA 3.0° and FPA 3.5°, respectively. Originality/value This study differs from prior studies because it focused on the effects of the different vertical profiles on FB. Also, the use of real flight data recorder data in the analysis presents the originality of this study.