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Delco Carousel IV-A INS For Microsoft Flight Simulator >> Delco Carousel IV-A INS For Microsoft Flight Simulator >> PPOS DIRECT to XYZ
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Message started by aca856 on Dec 8^th, 2008, 6:57pm

Title: PPOS DIRECT to XYZ
Post by aca856 on Dec 8^th, 2008, 6:57pm

I am new to the CIVA INS and have reviewed the documentation and tutorials.

WARNING: This is likely a "dumb" question.

Situation: You are at cruise going from WPT 3 TO WPT 4...ATC calls and clears you 'present postion DIRECT TO' WPT 6. What is the correct procedure to input this command into the INS?

I have tried changing FROM 3 TO 6 in the INS, but this does NOT calculate a lateral path to WPT 6 from "present postion" but seems to turn towards a path that seemingly originates from WPT 3 coordinates to WPT 6.

Clear as mud?

I am sure there is a 'correct' procedure to fly PPOS DCT to... please can someone help me out? 10 years of FMC NAV has spoiled me...DCT TO is easy, 2 buttons, EXEC, DONE :-)

Thanks in advance.

ACA856

Title: Re: PPOS DIRECT to XYZ
Post by mjanicki on Dec 8^th, 2008, 9:11pm

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

Title: Re: PPOS DIRECT to XYZ
Post by aca856 on Dec 8^th, 2008, 9:27pm

Thanks for the reply...I will try it tonight.

WPT 0 eh, interesting.

If I select WPT 0 should I expect to see the PPOS in the display?

Keeping the blue side up,

Rob.

Title: Re: PPOS DIRECT to XYZ
Post by Marco Ravanello on Dec 8^th, 2008, 10:16pm

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

Title: Re: PPOS DIRECT to XYZ
Post by aca856 on Dec 8^th, 2008, 10:20pm

Excellent information - thank you.

I am a little confused as with the start up sequence is to set WPT 0 and WPT 1 to the gate coordinates for distance/error checking before pushback. If WPT 0 is set to the gate coordinates, then does WPT 0 become PPOS when in the air? I guess I am missing something there with the logic.

I know, I am slow...like in a turtle kind of way :-)

Title: Re: PPOS DIRECT to XYZ
Post by Marco Ravanello on Dec 9^th, 2008, 4:54pm

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 ::)

Title: Re: PPOS DIRECT to XYZ
Post by aca856 on Dec 9^th, 2008, 5:26pm

That answered my questions - thank you!!!

I am surprised the Concorde was not retro-fitted with an FMS/FMC (or whatever Airbus call it :-))

Title: Re: PPOS DIRECT to XYZ
Post by Marco Ravanello on Dec 11^th, 2008, 8:56am

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

Title: Re: PPOS DIRECT to XYZ
Post by aca856 on Dec 11^th, 2008, 3:11pm

That makes sense...thanks Marco.

After some practice, I understand the INS workings now.

Thanks for the help.

Rob
ACA856