GPS Approach Cert
Just finished testing an FMS software upgrade to allow unrestricted use of GPS approaches on the Canadian C130. Our certification path has been long and winding...
The Transport Canada link provided earlier should have some good info, as would the FAA documentation on the design of RNP, LPV, and Baro VNAV approaches.
Drop me a PM if you'd like to chat and I can fix you up with some stuff...