Can my aircraft be equipped only with GPS for navigation and be legal for flying in IMC?
A. The FAA has authorized GPS as the primary means of navigation in certain areas (oceanic and remote). The FAA requires that the aircraft have the appropriate equipment necessary for the route of flight. Furthermore, a GPS approach cannot be used for the alternate if it is also used for the destination when using TSO-C129 equipment. Therefore, it may be legal to fly a GPS-only equipped aircraft in IMC, but the circumstances are quite rigorous. In Alaska , IFR-approved and installed WAAS avionics are legal as the only navigation equipment on board if the route and destination are identified for GPS/WAAS.
