In article ,
Roger wrote:

A solar storm can render the GPS signals unusable for a period and
have at least once if not twice. It's a rare occurrence. OTOH it is
possible, but with a low probability of either meteor (dust size
particles), or a solar storm of enough magnitude, disabling a portion
of the satellite constellation.

Right. That's why redundancy is critical. Vacuum powered gyros have been
a part of aviation for half a century, I don't see any reason why vacuum
couldn't provide the same level of redundancy for naviads. Put a really
big vacuum pump at the end of the runway and any aircraft that gets close
enough gets sucked right to the threshold.

"Cessna 12345, cleared for the vacuum two approach. Report established in
the vortex".