Now, I would like to know when you did flight testing and data gathering to proove that the calculations and tests made by the Airbus Engineers, Test Pilots and Flight Test Engineers are all wrong for managed descent, please send your data to Airbus Flight Test so they can correct their mistakes
Managed descent is not the most
fuel-economic descent because:
1. managed descent flies a geometric path in between altitude constraints
2. managed descent even in nil wind has some residual thrust above idle
(to account for engine anti-ice and statistical probability of reduced trackmiles to touchdown/early slowdown)
Even disregarding the above, Managed descent will only be the most fuel economic when flying Cost index=0. (commands green dot during descent and thus reduces time spent in cruise)
regards