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Wrightt

Vector instruction no SID - 2 issues

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When I depart an airport without flying a SID, assuming I am not following an airway, P2A calculates a course for me to follow that appears to run from the airport to the first waypoint without considering that after departure and following ATC heading instructions, by the time I am expected to assume my own navigation, I am no longer on that calculated course, but could be a fairly considerable distance off it. My internal navigation then heads me direct to that first waypoint, not to P2A’s courseline, but ATC tells me that I am off course. That is the first issue.

Then P2A says ,”You are off course. Fly heading XXX”.  And here is the second issue. I am obligated to follow the last clearance I received - fly a particular heading is as unambiguous as it gets, but P2A seems to assume, although it did not state it, that I will fly that heading until intercepting its own precalculated course, then change my heading accordingly - otherwise it tells me I am off course again. That clearance, IMHO, should be explicitly stated, not assumed. If I am assigned a heading, I follow it until otherwise instructed, and ATC should expect that I will do so and issue clearances accordingly.

I know I could obviate the issue be requesting a clearance direct to the next waypoint when they tell me I am off course, but I shouldn’t have to. Not a biggie, but I thought I would bring it up. Sorry if this has been explained elsewhere, but I couldn’t find it.

Thanks.

 

 

 

 

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After takeoff, with no SID, you should be instructed to turn to a heading "...to intercept course", which is the course you filed and therefore the course in P2A.  If you turn to that heading and then engage navigation to follow the GPS, if the plan in your GPS matches the course you filed, all should work out just fine. 

With a SID that includes a manual termination you will get a Heading and clearance to the next waypoint in the SID.  If this is what you're talking about, then please let me know the specific Airport, Runway and SID and I will have a look.  This logic is new and may have some bugs requiring attention. 

When you get an "off course" call, you should get a heading that is a 30 degree intercept to the cleared course/track. When you get back to that track, you will get a "resume navigation" which means resume navigating the cleared flight plan tracks.

Dave

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I understand that’s what should happen, but the “to intercept course” phraseology is missing, and the only clearance I get is “fly heading XXX”

As to the course filed and the course in P2A ... I filed this course:

KORD DUFEE ELX HAAKK DOXXY SOSIC JHW Q82 MEMMS WILET STELA1 KBDL

for a flight from O’Hare to Bradley KBDL. Departing runway 27C I made a right turn of about 180 degrees to head east which took me north of the airport, then entered LNAV mode which took me direct DUFEE. P2A advised me that I was off course and gave me a heading to fly. When I expanded the P2A map, its course line went from the center of O’Hare airport to DUFEE, and I was naturally to the north of that line, although headed directly for that waypoint. According to my aircraft’s instruments, I was precisely on course. Took me somewhat aback.

Edited by Wrightt
error

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Thanks for the additional details.

If you still have the P2A log file for this flight that might help me troubleshoot.  Please email to admin@p2atc.com

P2A Log files are located in: C:\Users\<UserName>\AppData\Roaming\P2A_200\Logs where <UserName> is your PC user name. 
Portions of the path may be hidden by default, so be sure Windows Explorer has Show Hidden Items checked in the View tab.
Dave

Edited by Dave-Pilot2ATC

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After loading the route and having a look visually, you may just need to increase the Allowed Course Deviation so that the turn doesn't trigger the off course call.

If flying airliner, try 2 or 3 NM for this setting.

If that doesn't fix it, send me the log file and I'll have a look.

Dave

Edited by Dave-Pilot2ATC

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I would still like to go back to the original issue.  Why does ATC try to vector you to intercept the course line from the airport to the first waypoint and not vector you direct to the first waypoint, then as filed?  From  what I can tell in the real world it seems you would get vectors directly to the first waypoint, not back to the course line between the airport and the first waypoint.  Not a major issue, everything works, it just doesn't seem right?   Thanks.

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