Operational issue - no dups allowed
Printed From: Avidyne
Category: Avidyne General
Forum Name: IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
Forum Description: Topics on Avidyne's IFD 5 Series and IFD 4 Series Touch Screen GPS/NAV/COM
URL: http://forums.avidyne.com/forum_posts.asp?TID=369
Printed Date: 28 Apr 2024 at 2:41pm
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: Operational issue - no dups allowed
Posted By: oskrypuch
Subject: Operational issue - no dups allowed
Date Posted: 20 Apr 2014 at 9:38pm
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When you have a waypoint specified in a route, inserting the same waypoint after it, is not allowed. Normally that is not an issue, but here is one situation which would require some fiddling. Let's say we are flying into KBED, ILS11. For whatever reason we execute a missed approach, but ATC gave us a heading to fly rather than published, which we begin to execute. Shortly afterwards they change their mind, and say "Fly direct ZIMOT, HOLD NE as published". Unfortunately, we can no longer execute the missed procedure. Also, we CANNOT put ZIMOT at the end of the route waypoints, because same waypoints are not allowed sequentially. We can key DIRECT and specify ZIMOT, which adds a waypoint BEFORE the approach kind of out of logical sequence, or add another "dummy" waypoint after the missed procedure, and then add ZIMOT, and then recreate the HOLD "as published". Both seem a little awkward. Your thoughts? Is there an easier way? * Orest |
Replies:
Posted By: Gring
Date Posted: 21 Apr 2014 at 7:47am
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Turn your heading bug to the RV specified, set your course to 223, go to the flight plan to the ZIMOT waypoint and press Direct, enter, enter. Since the waypoint is also the published hold, there will be a hold in the flight plan. Once you cross ZIMOT the flight plan will sequence to the published hold. Perhaps this was not a good example of what you are asking since ZIMOT is the published missed approach hold. If the request was some other waypoint not part of the approach, one could enter the fix at the end of the flight plan, highlight the fix and press direct, enter, enter. The press the right knob, select hold at fix, and enter the appropriate holding information. |
Posted By: Gring
Date Posted: 21 Apr 2014 at 8:10am
| I'll also add, that it is my opinion that the Direct to function on its own ie Direct To a fix or airport is of limited value and maybe only useful for VFR type pilots. I suggest always using a flight plan, even if it is only from point a to point b navigation. It prepares the pilot for more complex flying techniques and allows you to take advantage of the boxe's capability (true for both Avidyne and Garmin boxes). I cannot remember the last time I didn't use a flight plan other than flights in the local area where the destination was the departure airport. |
Posted By: oskrypuch
Date Posted: 21 Apr 2014 at 9:09am
... actually does NOT work, or work the way you might expect. It may be the simulator, or it may have been the phase of flight I was in, but touching ZIMOT on the flight plan, and press DCT does not fill in ZIMOT. If you force it by typing in ZIMOT, it creates a second instance of ZIMOT above the approach. I found that logically awkward, but is one workaround. The problem I describe, is actually born of wanting to use the flight plan. I agree that simple DCT to are more the venue of VFR pilots. * Orest |
Posted By: Gring
Date Posted: 21 Apr 2014 at 9:18am
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Did you press the "Activate Approach" LSK? When you enter a flight plan, then select a procedure, it loads the procedure at the end of the flight plan (reference your other question). You'll see a "Gap in Route" message in the flight plan meaning that you are still navigating to the airport and the approach has not yet been activated. Once you press the "Activate Approach" LSK the IAF becomes magenta and you are now working from within the approach component of the flight plan. You can now go "Direct To" any of the fixes within the procedure and it will sequence from there. I have not tried specifically going Direct To the MAP, but I have tried Direct To an IF within a procdure and it works correctly in the real box in a real airplane.
EDIT: I just tried it in the simulator as I described above and it works correctly. In fact, if you are in the hold at ZIMOT you can add additional fixes to the flight plan while the airplane is flying the hold. To exit the hold, simply highlight the next fix (the one you added) and press the "Activate Leg" LSK and the flight plan will sequence out of the hold and navigate to the next waypoint.
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Posted By: oskrypuch
Date Posted: 21 Apr 2014 at 10:43am
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OK, that was part of it. You can't DCT to a waypoint on the approach, until the approach is explicitly activated, different from the G logic which allows implicit activation. Similarly you can't DCT to a waypoint on the missed, until it is activated. However, the original issue remains. Once you deviate from the missed approach, to another waypoint off the missed, the missed is deselected, and can no longer be reselected -- unless you resequence the approach again. So, if you need to head to ZIMOT again, you would need to insert it "above" the approach, or add a dummy waypoint below the missed, so that you can add in ZIMOT below the missed waypoints (as duplicate in sequence waypoints are not allowed) Knowing about it, I can live with that, but that might be something to explicitly mention in the manual, easy to sort out when tinkering at the simulator, but it might be operationally confusing when busy in the air, on a critical missed. * Orest |
Posted By: oskrypuch
Date Posted: 21 Apr 2014 at 10:54am
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Actually, I can DCT to a waypoint on the approach, and that WILL cause an implicit activation of the approach. BUT, the missed is different, it requires explicit activation, and activation appears only possible when sequencing off the approach. * Orest |
Posted By: Gring
Date Posted: 21 Apr 2014 at 11:07am
| And I think that makes sense if you think about it. The entire approach is nothing more than a component or segment of the flight plan. You can add one, delete one, change one. Once you've navigated away from that segment, then it makes sense that you would have to reselect it or select a new one. |
Posted By: oskrypuch
Date Posted: 21 Apr 2014 at 11:24am
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Well, yes, that all makes sense. But, it does highlight the small limitation caused by the inability to have the same waypoint, duplicated, in sequence, in the flight plan. Nice to at least have the simulator, to figure all this out -- except for you lucky Experimental guys that have the real thing! * Orest |
Posted By: oskrypuch
Date Posted: 21 Apr 2014 at 1:07pm
And, talking to myself now, I'm wondering if that can be worked around in a future release by automatically inserting a discontinuity between duplicated sequential waypoints, to get around issues like this. The other place you could use this, is when you plan to fly a number of approaches at a given airport. It would allow you to add the airport in a number of times in the flight plan, and add the approaches later. Currently you would have to add the airport once as a destination, select an approach, and only then would you be able add the airport again to add another approach. In any case, not a biggie, once you know about it. * Orest |
Posted By: Gring
Date Posted: 21 Apr 2014 at 1:15pm
| "And, talking to myself now" You know that is never a good sign... |
Posted By: oskrypuch
Date Posted: 21 Apr 2014 at 1:25pm
Ah -- it was quiet on the forum!  * Orest |
Posted By: glassanza
Date Posted: 21 Apr 2014 at 7:56pm
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There are always folks checking in...I actually learned something here. Thank you Gring! ------------- GDC25 |
Posted By: AviJake
Date Posted: 22 Apr 2014 at 9:20am
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Have just added a few clarifying notes/tips in Draft 00-E of the Pilot Guide that I expect to post later this week. ------------- Steve Jacobson sjacobson@avidyne.com |
Posted By: oskrypuch
Date Posted: 22 Apr 2014 at 10:47pm
 That was fast. I'm not sure the "dummy" waypoint phrasing quite captures the situation described up thread, but no matter, the Tip Box does get the general message across. Here is a suggested different wording, for your consideration ... Back-to-Back Duplicate Waypoints Restriction The FMS will not permit entering back-to-back duplicate waypoints. When operationally required, a second duplicate waypoint instance must be inserted elsewhere in the active flight plan (such as above a loaded approach), or can be separated from its pair by first adding additional waypoint(s). A common scenario where this would apply, would be flying multiple practice approaches to a single airport. After adding the destination airport once, you should next add the first planned approach. That will append the missed approach waypoints after the airport, and allow you to add that same airport as a waypoint again. It is fun being "part" of the process. * Orest |