Cost Index

I have several FMC aircraft that ask for a CI. I've gotten into the habit of using a value of 30 for all flights and planes, and I'm happy with they way it comes out. For most of them, increasing it gets you there a tiny bit sooner, at a cost of more fuel.

Is that the norm? What is the range? So the higher I go the faster I can get to my destination? Can it automatically do it through a flight planner? Or should I stick with 30 depending on which plane I use? I'm still kinda confused by it. I just don't know if it effects performance of flight and distance of flight? I wish it would just calculate it and tell you which CI to use before takeoff.

Is that the norm? What is the range? So the higher I go the faster I can get to my destination? Can it automatically do it through a flight planner? Or should I stick with 30 depending on which plane I use? I'm still kinda confused by it. I just don't know if it effects performance of flight and distance of flight? I wish it would just calculate it and tell you which CI to use before takeoff.

The Cost Index is a management tool. The rw value can change based on price of fuel, aircraft, stage length, crew, etc. From an operating standpoint, the higher the CI the higher the speed and frequently lower cruise altitude as "optimum".

Most current airframes will see little cruise speed change with different CI's, but the more noticeable change is in climb/descent speed.

As a rule of thumb, lower CI with tailwind, higher with headwind; 30-50 is a good range. Typically, 199, or less, is the max value to enter and will keep it "on the barber pole".

Cheers!

Sean