Capn Bloggs,
I suspect that you may have missed the point .. the folk running the FOQA system have to develop their own techniques to determine the touchdown point .. I gave a few methods and there will be a number of others, depending on the recorder data captured for a given unit. FOQA is not a magic bullet .. it is a generic description for systems put in place to use recorder data for monitoring and related purposes. But, like any procedural gadget an organisation might develop to do something .. someone in the organisation has to do the developing .. or buy a similar system from someone else who previously did the hard yards.