BobbyFuzzy 88 Posted January 12, 2022 Share Posted January 12, 2022 Hey all, I wonder if someone can help me with this one... Last night I flew out of LSZH RW32 on the DEGES 5L SID. I flew the aircraft as normal, switching to FMS1 after the initial climb and set CLB 210. Managed the thrust in order to stay below 210 KT as per the SID & left the slats extended with a view to retract when further acceleration was possible. The aircraft flew the first turn correctly, overflying the ZH 580 & 569 as expected. Then turning towards ZH568 the aircraft turned over 180 degrees back on itself to intercept the leg inbound: Please login to display this image. I see that a direct is drawn between the 2 fixes which is correct according to the SID, after overflying it's a left turn and direct ZH568, however, I would have thought that considering the aircraft has also drawn in a nice left turn, the aircraft would not try to intercept the next leg at such a steep angle or even fly back on itself like in this scenario. This took me by surprise and unfortunately as I was busy switching frequency I did not catch this before it was too late, ending up in a bit of an awkward spot before I was able to intervene, switching to HDG (and given subsequent vectors), however, I wonder if anyone can verify or not whether this is the expected behaviour? Thanks, Rob Link to comment Share on other sites More sharing options...
LesOReilly 314 Posted January 14, 2022 Share Posted January 14, 2022 On 1/12/2022 at 8:38 AM, BobbyFuzzy said: Hey all, I wonder if someone can help me with this one... Last night I flew out of LSZH RW32 on the DEGES 1L SID. I flew the aircraft as normal, switching to FMS1 after the initial climb and set CLB 210. Managed the thrust in order to stay below 210 KT as per the SID & left the slats extended with a view to retract when further acceleration was possible. The aircraft flew the first turn correctly, overflying the ZH 580 & 569 as expected. Then turning towards ZH568 the aircraft turned over 180 degrees back on itself to intercept the leg inbound: Please login to display this image. I see that a direct is drawn between the 2 fixes which is correct according to the SID, after overflying it's a left turn and direct ZH568, however, I would have thought that considering the aircraft has also drawn in a nice left turn, the aircraft would not try to intercept the next leg at such a steep angle or even fly back on itself like in this scenario. This took me by surprise and unfortunately as I was busy switching frequency I did not catch this before it was too late, ending up in a bit of an awkward spot before I was able to intervene, switching to HDG (and given subsequent vectors), however, I wonder if anyone can verify or not whether this is the expected behaviour? Thanks, Rob I can't find the 1L SID so I have to think you have older Database ... the 1P looks similar but with a shift in one of the waypoints... Please login to display this image. The FMS draws the straight line but I don't think it can fly the RF Leg..... You might need to use HDG mode as you cross over the first Fix to fly a Turn to get you to the second fix. Link to comment Share on other sites More sharing options...
BobbyFuzzy 88 Posted January 14, 2022 Author Share Posted January 14, 2022 My apologies @LesOReilly I had made a typo! It was the DEGES 5L departure. In my example and yours I do not believe the turn is an RF Leg. Looks more like a DF to me? As noted in the bottom right "turn RIGHT direct ZH571" in your example, implying the turn radius is of little concern. Link to comment Share on other sites More sharing options...
KuntaKinte 210 Posted January 14, 2022 Share Posted January 14, 2022 It is indeed the DEGES 5L with the first two waypoints (ZH580, ZH569) as "flyover" waypoints. The FMS indicates this with an arc segment in the extension of the respective waypoint (as shown in your screenshot). As a result, the aircraft will overshoot the flightplan path and will reintercept afterwards. That would have been easy here without a steep angle. From your screenshot it almost looks like if the aircraft was trying to intercept the course backwards to ZH569. I tested this yesterday about four times. While I never encountered exactly your problem, I experienced following: The AS CRJ was always exaggerating the beginning of the turn to ZH569. One moment later, it even had to turn back in the opposite direction to compensate for this exaggeration. Shortly afterwards it banked in the original direction again. So, instead of a smooth and continuous intercept, it was a whobble-o-rama. All of this is not expected behaviour under any circumstances. And your case in particular would scare air traffic control and all following aircraft. Link to comment Share on other sites More sharing options...
BobbyFuzzy 88 Posted January 15, 2022 Author Share Posted January 15, 2022 Thanks Matthias! I'd thought as much. On 1/14/2022 at 4:09 PM, KuntaKinte said: And your case in particular would scare air traffic control Yes the controller on VATSIM was a little confused, let's say! Link to comment Share on other sites More sharing options...
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