Cost Index B737
Enter a CI in FMC. The CLB & CRZ speeds vary depending on gross weight; 1 parameter. Why does the descent speed remain constant for differing weights?
A friend has just been instructed to enter a very low CI which gives 245kts in descent. He wonders if he then speeds up to 250kts passing FL100? (I know this is a max, but everyone does it) Many years ago there was an easyjet thread on here about using very low CI's and it causing very slow descent speeds at high level and ATC asking them to speed up. This could only be done with power, thus negating the low CI to save fuel. i.e. it is a known failing. I wonder why another airline would try something that has already caused problems.
I realise this is 2 threads, but they are related, if only distant cousins.