The OP wanted to use landing data from actual landings in FlightGear - the easiest way to obtain that would be to use a handful of airports/runways and different environmental settings, and then batch-run these in FlightGear while creating a recorded flight (fgtape), possibly using time-warp mode - at that point, dozens or even hundreds of fgtapes could be created automatically, and then post-processed using a neural network.
For example, imagine querying the navdb for ~10 airports, each having at least 3 runways (+ reciprocals), using 5 different weather scenarios, and 5 different aircraft, you'll quickly end up with hundreds of fgtape files in a semi-automated fashion.
You could even run a PID controller to fly each approach (sampling the surrounding terrain upfront to determine a MSA and suitable orientation to vector the aircraft)
Note that such a setup could even run FlightGear in headless mode, i.e. all you care about are the flight dynamics/terrain clearance and getting your hands on the sampled data (flight profile).
In summary, the kind of data you need is very much overlapping with the GCA/PAR add-on functionality:
http://wiki.flightgear.org/PAR_instrumentAlso, this is overlapping with the idea of creating a mission generator:
http://wiki.flightgear.org/FlightGear_M ... AdventuresTo speed up things even more, consider running the fdm (think jsbsim) in standalone mode.
Another option would be hooking up an observer script/module to gather flight data that way, and serialize it to disk - or even customizing a fgms fork along these lines.