A320 Just Committed a Sin

So I’m cruising along to KLAX on the HLWD1 STAR. I prep the MCDU with approach data and dial in a lower altitude on the FCU for the first descent restriction of 17,000. I don’t touch the altitude knob. Moments later the A320, on it’s own, starts a descent and goes into DES mode.

Wrong. This is an Airbus, not a Boeing. That is a HUGE fundamental error. You have to PUSH or PULL the altitude knob to get the Airbus to descend. It does not do it on its own like a Boeing.

Honestly though, the VNAV has gotten MUCH better from Alpha. Arrivals into KLAX from the East are pretty complex with restrictions in altitudes all the way down. So far, the A320 is hitting them all very well.

Still some work to do but good progress.

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Have you seen a ToD marker, so how would you know when to push? (Altitude/ Distance, manual math yes…). Were you able to manually enter Alt restrictions for waypoints on the STAR?

Thanks!

No T/D marker. 0.3xFL to lose is the formula to approximate your T/D. For me, this was 26 miles so that’s when I would have started the descent. Didn’t have to manually enter the restrictions. They were already present from the STAR and showed up on the ND as well. That was a huge step forward.

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Are you absolutely sure that you could not have inadvertently engaged an altitude mode when you changed the FCU altitude? I haven’t seen this happen in the release version. Guess I will have to do some more testing. In one of the later alpha and maybe the beta version I had it climb above the FCU altitude in managed altitude mode with a higher altitude specified in the FMGC flight plan, but I haven’t had that occur in the release version, so I thought they had these things fixed.

You know, thanks for flagging that. It is certainly possible. I will have to test this again as I found it very odd. The timing was very close from me dialing in the altitude and the aircraft initiating the descent. I’ll correct if so!

Well, you know, I just had an occurrence where it shot right through my FCU altitude during a climb in managed altitude mode. Looked at the PFD and saw it had a higher altitude in red than I had set in the FCU. Went to the FMGC and saw that altitude in the flight plan as an altitude constraint. But the airplane should never go above the FCU altitude in a climb, just like it should not go below it in a descent. I guess that hasn’t been fixed. My bad.

Hey, we’re all here to share insights so all good! Worth me checking again. Once I was on the descent, the STAR I was flying had multiple altitude restrictions. I had my FCU altitude set at the lowest restriction. Several times I noticed the airplane doing the right thing and leveling off at an intermediate restriction, then continuing the descent on the other side. I’m going to fly this route again to see what happens.

@AwarePlot117729, following up on the unintended descent in the A320. I can confirm this has occurred. I flew the same STAR and dialed in 17,000’ well before TOD would have been. 10 or so minutes later the aircraft went into managed DES mode and started the descent on its own. Not good.

Not only that, I was cruising at FL260. It started the descent to 17,000’ more than 80 miles from the waypoint with the altitude restriction.

So the concepts of managed descent is there but the implementation is still pretty far off.

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Can you put a report, including all the specifics, in to Zendesk? I’ve done it for my example, but the more there are the more attention it will get. Thanks.

yes, I was planning to do the same

Submitted bug with Zendesk and posted to forum here: [SENT BUG] A320 Initiates DES mode automatically

Maybe the in game Neo hasn’t received the 2020 Airbus update software to fix its pitching and alt issues the restricted passengers in the back sections.

Both have to be patched clearly.

IT will get there, but right now they have soem base lien tweaks to adjust.

Like worthless co pilots
Optimizations
Lack of direct X 12
Low alt left to right shifting on autopilot not compensating for ridges.

Insert long list here.

It will get there yes. I’m more concerned about the critical functions of the MCDU, FMGS and MCP than other frills at the moment. It is a very solid start. I’ve paid for payware on other platforms that wasn’t as good as what we have now. For an A320, that is the baseline and an absolute necessity to be true to the fidelity of the aircraft.

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The nav data needs some work also. My last flight in the A320, it was able to load the STAR, but didn’t have any of the restrictions and I couldn’t enter them in the MCDU. Math it is!

The A320 will be a “selected mod only” VNAV aircraft until the especially critical descent phase is fully replicated in the MCDU, and able to be executed by the FMGS. I’ve seen this before however with other payware add-ons that take a while to get the managed modes of the A3xx aircraft dialed in. For the A320, I’m only aware of two vendors with exemplary versions of this for P3D and X-Plane.

The good news on Nav data, perhaps, is the fact that navigraph will provide FMS data to MSFS. Not sure how that will be implemented but could help with SID/STAR speed and altitude restrictions. It’s there now for some approaches, just not all.

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Yep…I’m in the Navigraph beta…will be testing tonight. If that includes the alt and speed restrictions, it will be awesome! If not, I’ll be sticking with math…lol.

Just seen this post. Bit late at the party but I am horrified!

Was trying to figure out des/decel so saw a Youtube vid of a real 320 pilot flying the sim. He worked out with pencil and paper what you needed to do to descend! He said that is what you do in the REAL LIFE aAirbus. REALLY?

This is the most modern , biggest selling airliner and you have to manually work it out? Unbelievable!

Was flying the 737 (Zibo mod) in XPlane before MSFS. No problem there. TOD/BOD clearly marked and it does as it says on the tin.

Doesn’t it seem strange that clm/cruz phases are followed but des is not?

I believe there may be some A320 pilots lurking here. I’m going to say, no, real A320 pilots don’t use pen and paper to plan a descent. That’s what the automation is for. What we have now does not match up well to the real airplane. I fly other A320 simulators and have never needed manual calculations as we do here. That is because it does not fully model the MCDU and FMGS so impossible to really provide accurate VNAV guidance.