Mxsmanic wrote in
:

Mike writes:

The number of passes they make depends on what type of ILS it is and
what check they are doing. I've seen them take several hours to do a
CAT III ILS. For a typical CAT I ILS they will check it once per
year making about 3 approaches and an arc. Every other year they
will do a more extensive check. The equipment is also checked
extensively on the ground at regular intervals.

How do they fly the plane with sufficient precision to make the check
valid? Or do they use methods that are independent of the precision of
the aircraft's movements (if so, what are they?)?


What's it to you? You don't fly.


Bertie