Cost Index

[Michael Blakely]

I always use 80%.
Gas is cheap, right?

[Theodore Martin]

I always use 90 for my cost index. Gives me a good cruising speed of between M.78 - M.82 depending on the a/c. However I do use 40 on the Airbus because that was the recommended index from the tutorial and the Airbus FMC is "backwards" to me anyway (i.e. read very strange for me).

I actually have a file I downloaded from somewhere that provides the standard cost index utilized by each airline, however I don't use it.

[Theodore Martin]

I use 50% almost every flight. I was using 90% until I got tired of the "Insufficient Fuel" message in the FMC. Have never seen that since I started using 50%

The "insufficient fuel" message may be due to the percent you enter into the "reserve" field. If that number is too high (I normally use 3%, saw it in a tutorial) it will require you to have a lot of additional fuel. I almost never get the insufficient fuel message and I never use anywhere close to a full load of fuel.

If you don't enter any value in the "reserve" field I'm not sure what value it uses as the default. Could be defaulting to a high value.

[Todd Meek]

I typically use 50 for cost index and 5% for reserve. Just what I've been using but I'm still fairly new to the FMC but building experience.