Fuel and time savings by flying continuous cruise climbs: Estimating the benefit pools for maximum range operations. (March 2015)

• Record Type: Journal Article
• Authors: Dalmau, Ramon; Prats, Xavier
• Is Part Of: Transportation research. Volume 35(2015)
• Page Start: 62
• Page End: 71
• Publication Date: 2015-03
• Subjects: Continuous cruise climbs -- Unrestricted flight -- Fuel savings -- Trajectory optimization; Transportation -- Research -- Periodicals; Transportation -- Environmental aspects -- Periodicals; 354.76
• DOI: 10.1016/j.trd.2014.11.019
• Languages: English
• ISSNs: 1361-9209

Abstract

Highlights: Comparison of fuel and time savings between current and unrestricted cruise flights. Aerodynamic compressibility effects and accurate engine limitations considered. A multi-phase optimal control problem is solved to obtain the trajectories. Continuous cruise operations not only save fuel, but also flight time. Abstract: This paper estimates the benefits, in terms of fuel and time, which continuous climb operations can save during the cruise phase of the flights, assuming maximum range operations. Based on previous works, a multiphase optimal control problem is solved by means of numerical optimization and using accurate aircraft performance data from the manufacturer. Optimal conventional trajectories (subject to current air traffic management practices and constraints) are computed and compared with ideal continuous operations only subject to aircraft performance constraints. Trip fuel and time for both concepts of operations are quantified for two aircraft types (a narrow-body and a wide-body airplane) and a representative set of different trip distances and landing masses. Results show that the continuous cruise phase can lead to fuel savings ranging from 0.5% to 2% for the Airbus A320, while for an Airbus A340 the dispersion is lower and savings lie in between 1% and 2%. Interestingly, trip time is also reduced between 1% and 5%.