On Apr 4, 9:11 pm, Mxsmanic wrote:
Nomen Nescio writes:
The category that has wings and goes up in the sky.

You mean like a 747-400? It has two GPS receivers, three IRUs, two VORs and
two ADFs. One rarely falls back upon the magnetic compass.

But when you have to, you're damned glad it's there. Take for
example, the Gimli Glider or Air Transit glider, more recently. In
both planes, when the engines ran out of fuel, the only standby
instruments left we a magnetic compass, an artificial horizon, an
airspeed indicator and an altimeter.

Kev