Just keep in mind that waypoint zero is current position and it should make sense.  When given direct from current position to WPT 6 instead of changing the INS to go from WPT 3 to WPT 6, change it to go from WPT 0 to WPT 6 and that will give a direct route.

-- Mike

In INS terms, DIRECT TO corresponds to commanding a 0-X leg change (where X is the selected waypoint number, #6 in your example).

Marco

First of all you have to keep in mind that waypoint #0 is NOT "editable", you cannot modify it.

At startup time, on the ground, you will enter the PRESENT POSITION (to alignment the INUs) and that will set waypoint #0.

Then you enter the very same coordinates as Wpt #1 to check that present position has been inserted correctly (0-1 distance must show ZERO NMs).

> then does WPT 0 become PPOS when in the air?

Not exactly. Once in flight, waypoint #0 does not seem to change but if you command a 0-X leg change you will see that it will change and will actually be set to the coordinates of the point where you have commanded the leg change.

> I know, I am slow...like in a turtle kind of way

It's not easy to learn how this old equipment work. I programmed this gauge and still have problems using it sometimes

I'm not an expert but I believe that upgrading part of an aircraft avionics is not a simple and cheap job. The INS is not a standalone unit, it is connected to a LOT of other sub-systems so you cannot just plug it out and insert the newer FMC.

Also if an equipment is sufficient (precision, safety, tolerances etc.) then there is no need to upgrade it.

Marco