There was a time, not too long ago, when oil prices had peaked and jet fuel was a very expensive commodity. In times when jet fuel is as expensive as it is, fuel conservation is a mission critical exercise.
Aircraft design over the years has evolved to provide help in this direction. The Flight Management Computer (FMC) also called as the FMS was itself a revolutionary innovation. One of the features of the FMC is the Cost Index.
The cost index (CI) feature of the FMC can help air carriers reduce operating costs. significantly reduce operating costs.
While coming up with the Cost Index itself can be a complicated task, once that number is available and used in the FMC, the FMC uses it to compute aircraft performance primarily to maximize speed, minimize fuel burn.
Bill Roberson, Senior Safety Pilot, Flight Operations @ Boeing, wrote a really detailed article in the AERO newsletter back in 2007.
The concept is so valuable that it has become routine in aviation operations.
References:
Roberson, B. (2007). Fuel Conservation Strategies: cost index explained. Boeing Aero Quarterly, 2(2007), 26-28.
WU, J. D., WEI, Z. Q., & NIE, R. T. (2007). Calculating and Analyzing Cost Index Based on Long Range Cruise [J]. Journal of Civil Aviation University of China, 3.
Cook, A., Tanner, G., Williams, V., & Meise, G. (2009). Dynamic cost indexing–Managing airline delay costs. Journal of air transport management, 15(1), 26-35.
The Cost Index – what is it?
