"For the next week, the radar on this Astrojet won't see anything
but Tulsa.
Every time we overhaul a jet at our Tulsa base, the whole radar
system is removed and taken completely apart.
First, each part is cleaned - of nicotine stains, for one thing.
(Cigarette smoke from the cabin gets in out Astrojet's eyes.)
Then come lab tests - and 100% is the only passing mark.  
Transmitter signals are tested in a block of lead so they won't fly
around and hurt anybody.
Next, we put in new parts (bearings, brushes, etc.) and put the
unites back together.  And we shoot for even closer tolerances
than when they were new.
Now we set the system up in a tower to see if it knows where
Tulsa it.  And then, if its perfect, we test it again in the air on the
Astrojet itself.
The job takes 46 men - and each has a First or Second Class radio
license.  Quite a status symbol in radio circles.
And this is just the radar.  Our overhaul staff is 2300.  Imagine
what we do to the rest of the plane."