A320 Cost Index and descent speed

[I-WEBA]

Hi everybody

I'm just a flying lover, really curious about everything concerning flying.
I was reading about CI on A320, I would like to know how varies the descent and climb speed on CI0 CI6 and CI12. I read that for some operators most of the time CI6 a value of 270kts, for others 250. I read getting to grips with cost index and it gives values much higher.

Kind regards

[halfofrho]

For my airline, we use either CI6 or CI12. The biggest effect that this has is on our cruise mach number. Generally CI12 will give you about Mach .78 at FL390 where as CI6 may give you .76 or so. On descent the aircraft will always use 270kts on conversion from mach to speed.

I think the descent speed is in fact a customer option with Airbus, and not wholly determined by cost index, but someone may be able to tell you differently.

[I-WEBA]

Thank you for your answer... What about climb speed?
I am really curious, Which routes is CI12 for? For routes with headwind expected or for routes with long taxi time or for others?
Thank you very much

Kind regard