Sunvox

Please go to our WOM AT10.11 under Mach Number Technique and it says this"It is acceptable to use the Cost Index/ECON to maintain assign Mach..."

So what trumps?

Is it International Law to not use ECON or is it a route regulation to maintain assigned Mach?

Damned pesky details!

I fix the Mach per your reference to avoid writing reports because of a violation of maintaining assigned Mach, per the FOM.

These conversations sure weed out the details. But why would any one risk not maintaining the assigned Mach by using ECON? I guess some just like to live life on the edge!