Originally Posted by
aviatorhi
Clearly this has never happened to you... while it happens about once every month or two to me.
Rapidly is subjective, but in the span of a few minutes you'll be at a few miles when on inertial only.
GPS jamming NOTAMS, alerts issued by the FAA. GPS anomaly? Yeah consistently near an intersection over the Italian/Swiss boarder. Got they typical RNP message in the FMC/CDU. Came back to life before I had the chance to cancel the message.
Operated across the Pacific with IRS’s. Average leg was 10 hours plus. Required to log velocities and distance errors 10 minutes after the parking brake was set. Trying to remember the greatest distance error was about 2 miles. That said No biggy, unless you need to accomplish a LPV approach.