It seems like the iniBuilds A350 mostly cruises at Mach .850 and this does not change with cost index when above the crossover altitude. The OFP however does include a variable speed schedule based on cost index, which may cause inaccuracies in ETA and EFOB predictions. Low OFP CIs will lead to shorter flight times and higher fuel burn than planned, whereas high CIs might cause excess fuel and longer flight times than expected.
Would it be possible to adjust the Cost index data for the A350?
