Paul Tomblin wrote:

It couldn't lock on AT ALL? Or it would take a little while? I thought
LORAN was an absolute positioner (like GPS) not just a relative positioner
like INS.

It won't lock on at all - it has to be initialized (you have to input the
latitude and longitude).

Are you going to tell me that all those LORANs in people's boats have to
be on all the time the boat is being trailered?

I don't know about boats, but that would not be the case with aircraft, either.
I can cut my LORAN off, fly from 3N6 to anywhere, return to 3N6, and the LORAN
will work fine when I cut it back on again. What I *can't* do is cut it off,
fly from 3N6 to, say, FDK, turn the LORAN on and expect it to lock in.

The problem is that the LORAN determines your position by timing signals from
three transmitters. This group of transmitters is called a "chain". The box
can figure out, for example, that you are 30 miles from transmitter #1, 35 from
#2, and 15 from #3. The problem is that there are two places on Earth that are
these distances from those transmitters. If you happen to be very close to the
last place you shut down when you turn the box on, it figures that you haven't
moved.

If you moved the plane since you shut the LORAN down, it won't know which of
those two positions to use when you turn it back on. If you are at a location
at which any two of the transmitters are nearly in line, you don't have to move
the box far to confuse it.

There's also usually a battery on the board to allow the LORAN to remember where
you were the last time you turned it off. My LORAN will not work at all if this
battery dies.

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.