Until there is a big solar storm knocking out GPS at the same time as a magnetic field anomaly.
One day soon the poles WILL flip and for a brief time navigation will be problematic.
Its been suggested that something very much like this might have done for MH370.
The working hypothesis is that there happened to be a brief magnetic spike in the area which has
in fact been reported before by both shipping and aviation.
By sheer coincidence one of the passengers had a faulty phone that "hooted" on the GPS L1 and L2
bands and this unfortunately coincided with the magnetic anomaly causing the plane to fly in effective
circles until it ran out of fuel.
Normal communcations being knocked out may well have been a short in the wiring: likely the
transmit side went bad or off frequency but reception was still possible.
Similar issues have been reported before with older equipment more susceptible to certain types of