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Issue transitioning from a Fly-over waypoint to next RNAV waypoint


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Hi guys,

Just would like to report a bug. I flew the CRJ on an RNAV SID this one out of the Philippines in Legaspi. The RNAV SID (NAGA 1E) has a Fly-over waypoint for the first turn followed by a 90 degree turn to the next waypoint. The other waypoints are fly-bys. 

The AIRAC database is correct, the airplane did indeed fly over the waypoint before turning however, as the aircraft is turning and obviously there would be an off-track to one side and the aircraft should re-intercept the ideal track, the airplane basically flew in a circle instead of intercepting the waypoint at an ideal angle. There was no speed limit on the SID so I was flying it at 250KT IAS climb. I'm guessing that this is due to the large intercept angle as a result to the OFFSET track caused by flying over the waypoint before intercepting the 90 degree track to the next waypoint.

Not a significant issue and I certainly am very enthusiastic of this project as it improves. Philippines have mostly RNP approaches and looking forward to further improvements on the automation. I have been playing around with the VNAV manage descent as well but it is mostly hit or miss probably depending on how the automation interprets the database. Again not a big deal as I understand it that the CRJ is not necessarily rated to LNAV/VNAV minima and the approach could be done using VS mode following the VNAV guidance on the approach crosschecked with the charts.

Loving this project guys. This is the closest thing to the ATR 72-500/600 that I fly in real life in terms of complexity.  

Thanks guys.

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2 hours ago, LesOReilly said:

It is listed as an RNP 1 ....  Not sure if that is the root of the issue...

RNP 1 should be OK in the CRJ

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It would not matter. RNP just represents required performance. A typical RNAV approach would be 1.0 until the FAF to which it switches to 0.3. Most SIDs and STARs are RNP 1. I would expect that CRJ RNP system would maintain ANP of well below 1.0 in either case.

 

I think this is just a case of a too tight of a turn resulting in a big intercept angle. The first waypoint of this SID is a flyover waypoint making it all that much larger. I am quite happy actually that the FMS recognized from the AIRAC that it was a flyover waypoint. Most waypoints are flybys meaning the FMS leads the turn to the next outbound track depending on speed and angles involved, however not all waypoints are flybys. Flyover waypoints are marked a a circled star on the charts. For those you need to fly over the waypoint before making the turn for the next track.

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3 hours ago, 9012 Pilot said:

It would not matter. RNP just represents required performance. A typical RNAV approach would be 1.0 until the FAF to which it switches to 0.3. Most SIDs and STARs are RNP 1. I would expect that CRJ RNP system would maintain ANP of well below 1.0 in either case.

 

I think this is just a case of a too tight of a turn resulting in a big intercept angle. The first waypoint of this SID is a flyover waypoint making it all that much larger. I am quite happy actually that the FMS recognized from the AIRAC that it was a flyover waypoint. Most waypoints are flybys meaning the FMS leads the turn to the next outbound track depending on speed and angles involved, however not all waypoints are flybys. Flyover waypoints are marked a a circled star on the charts. For those you need to fly over the waypoint before making the turn for the next track.

Well there have been issues with regards to RNP Procedures including a STAR that was an RNP/AP that has caused the CRJ to Lock up or even crash the sim...

 

The AS CRJ can not filter out the procedures that the real plane can not use and this has added to the reports....   

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