One of the tasks of the technical pilot is,in our comp, to make sure that all required instruments ore systems are installed ,functional and fully understood by the pilots ( for ex monitor the introduction of TCAS ,or 8.33khz radios, or any 'will be' mandatory systems)
Also ,maintain connection between flying and technical department, and inform eachother department about the neeeds of the other one.
Assist the flight safety dep. also, with regard to technical aspects.
We have a technical pilot for every fleet.It is not a test pilot,it doesn't do the certification flights.
This is a new position,required by the JAA regulations ,I guess.