March 8Mar 8 I've noticed some circumstances where if I'm on a STAR and I have a waypoint with a upper and lower altitude limit (like 12,000 / 10,000), the VNAV will descend a a pretty high rate to the lower limit and then level off and fly at 10,000' to the waypoint. This doesn't seem to be correct (or is it?), I figured the VNAV would compute a descent rate to avoid leveling off. Is this accurate in RL?
March 8Mar 8 1 hour ago, 11bee said: I've noticed some circumstances where if I'm on a STAR and I have a waypoint with a upper and lower altitude limit (like 12,000 / 10,000), the VNAV will descend a a pretty high rate to the lower limit and then level off and fly at 10,000' to the waypoint. That could make sense if the aircraft was decelerating during the level segment (was it?). Otherwise, that does sound suboptimal. Fenix have said on the Discord that some improvements to the VNAV are in the pipeline, so that implies they're aware of areas where the current behavior isn't optimal.
March 8Mar 8 Author 21 minutes ago, weaklink said: That could make sense if the aircraft was decelerating during the level segment (was it?). Otherwise, that does sound suboptimal. Fenix have said on the Discord that some improvements to the VNAV are in the pipeline, so that implies they're aware of areas where the current behavior isn't optimal. No, I was on speed and there was no deceleration required for that segment. 1000' FPM descent to 10,000' and then 8 miles to fly to the waypoint, where it then started a decent to the next altitude constraint.
March 8Mar 8 6 hours ago, 11bee said: I've noticed some circumstances where if I'm on a STAR and I have a waypoint with a upper and lower altitude limit (like 12,000 / 10,000), the VNAV will descend a a pretty high rate to the lower limit and then level off and fly at 10,000' to the waypoint. This doesn't seem to be correct (or is it?), I figured the VNAV would compute a descent rate to avoid leveling off. Is this accurate in RL? It should not do that in VNAV. The airplane should arrive at the WPT on altitude and speed unless it has deviated from the path/profile and is compensating for that deviation. If you were on profile in managed descent, this should not have happened. If you switched momentarily to open descent for a while and got significantly below the path, and returned to managed descent before 10K, it will level off to cross that WPT restriction and then continue on schedule again. Edited March 8Mar 8 by LRBS 747 Captain for the last 39 years, and still learning.
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