NZFF

This is a new FSPS add-on for FSX, somewhat similar to Accu-Feel in a way. It tries to stretch realism by providing proper icing simulation and adding enhanced brake and acceleration to your aircraft based on temperature and other factors. It also simulates the affects of runway contamination, Anti-Skid for all aircraft and sound effects.

Very interesting, but it costs more than double of Accu-Feel... Not sure about the marketing strategy behind it...

http://secure.simmarket.com/fsps-sim-physics-x.phtml

Could be the ideal tool if you like to follow some of the data you can get from real world crash incidents and see if you can fly your way out of trouble .