Andrew Sarangan writes:

I don't claim to know anything about navigation over the poles, but if
it is as simple as you say it is, why do we continue using the
magnetic compass for every-day navigation? My guess is that it must be
complex, difficult, expensive or unreliable.

I think magnetic headings are still used because of the vast inertia
of the installed base of avionics and instruments, plus the inertia of
so many pilots who have been raised on that.

I certainly won't quarrel with using magnetic navigation as a back-up,
but I do question basing normal navigation on a compass, which is
relatively unreliable compared to more modern methods. If the SR-71
could navigate reliably by the stars half a century ago, I think most
aircraft could navigate reliably today using much more modern
satellite systems.

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