Missing altitiudes and VNAV doesn't work

[Abiofly]

Hello

After update to 1.21 twice time I have a problem with VNAV. First flight from LGAV to LIRN and now form LIRN ISKIA M603 PNZ M729 MEDAL M729 IDONA LIMJ. Everything was ok until a set DEPARTURE  RWY 24 ISKI5A and then some waypoints have gap/missing altitiudes including ISKIA waypoint When set manually altitiudes VNAV work.

Grettings

Krzysztof

[Abiofly]

Hello

Next Flight this same problem. LIMJ LAGEN M859 VAMTU UM984 DIVKO UN975 BISBA LEBL and I have checked all waypoints and there where all altitiudes but VNAV didn't work. I started manually and after last SID waypoint before LAGEN, LAGEN changed 250/55FL A to 250/------ why??? After set LAGEN 250/180FL VNAV work ok. It's Very frustraiting please do something with that.

Grettings

Krzysztof

[Morten]

Hi, understand your frustration, but we have not seen this from anyone else yet. We need screenshots and logs. I assume you have closed all disco's?

[Litjan]

11 hours ago, Abiofly said:

Hello

Next Flight this same problem. LIMJ LAGEN M859 VAMTU UM984 DIVKO UN975 BISBA LEBL and I have checked all waypoints and there where all altitiudes but VNAV didn't work. I started manually and after last SID waypoint before LAGEN, LAGEN changed 250/55FL A to 250/------ why??? After set LAGEN 250/180FL VNAV work ok. It's Very frustraiting please do something with that.

Grettings

Krzysztof

Hi Krzysztof,

you may not be quite up to the current status of our VNAV implementation. Unfortunately VNAV is unable to follow more complex arrival procedures, and it also fails to read some restrictions from the database (especially waypoints with both above and below).

For now you will have to fly descents like real pilots mostly do - in FL CHG or V/S modes, calculating the descent parameters in your head.

We are working on improvingh VNAV in the future, so that also less experienced pilots can fly complex arrivals.

Cheers, Jan

 

[Abiofly]

Thank you for your answer Jan. I have problems after departure not arrivals and descend. I have changed all A to specific altitiudes and works fine:) I will waiting for next update

After update 1.21 Xplane crashed and stopped during the flight about three times for five flights. Is it possible to do this because update to 1.21???

Grettings

Chris

Edited February 22, 2018 by Abiofly

[Litjan]

1 hour ago, Abiofly said:

 

After update 1.21 Xplane crashed and stopped during the flight about three times for five flights. Is it possible to do this because update to 1.21???

That is hard to say without knowing the exact nature of the crash. But if X-Plane itself crashes, it is usually due to some plugin incompatibility. The way to narrow this down is to remove all other plugins for testing, then see if it still crashes. If not, add them back in one by one until the crashes happen again...

Jan

 

[Ben Russell]

3 hours ago, Litjan said:

That is hard to say without knowing the exact nature of the crash. But if X-Plane itself crashes, it is usually due to some plugin incompatibility. The way to narrow this down is to remove all other plugins for testing, then see if it still crashes. If not, add them back in one by one until the crashes happen again...

Jan

 

in this instance it’s probably gizmo. 

personal circumstance for the last few months has been tired and stressed. we have a multitude of weird bugs going on.

under these circumstances its probably my work at fault. sim crashes are just yet another way the problems can manifest...

[sdflyer]

In 1.2 VNAV does't work. Simple approaches, complex approaches it doesn't matter - it hangs at the wrong altitude at the most easiest descend profiles.  It should be deferred, placard, and logged as inop

[Capt.Stanford]

Haven't tried VNAV yet, Jan you said that real pilots (assuming on the 737CL) use V/S & FLCH for descent? I thought they use VNAV for descent

[Cameron]

1 minute ago, Capt.Stanford said:

Jan you said that real pilots (assuming on the 737CL) use V/S & FLCH for descent?

Correct.

[Capt.Stanford]

Guess I was misinformed, I'm starting to think that VNAV on the 737 (at least for now) is somewhat like an advisory system used on CRJ aircraft, I'm about to start training for my Instrument Rating here at University & I use flight simulators (X-Plane/P3D) along with Navigraph to help me practice SID/STAR procedures, so it is important for me the FMC has somewhat full VNAV functionality.

It's still a good plane anyways even if the FMC is not fully functional, hopefully IXEG will release an update soon. Exactly when we'll find out soon enough hopefully

[Shanwick]

VNAV on the SID/climb all the way up to cruise alt works flawlessly. It also calculates top of descent correctly as long as there are waypoints that have hard altitudes. Descending correctly is pretty easy via V/S and calculating top of descent in your head with a simple formula and you will hit every waypoint at the correct alt. The green energy arc/ green banana on the nav display helps too. Once you know your top of descents you can set up the green range rings in the FMC's FIX page. I personally rarely use VNAV, even if it was working. It's just too easy for me. But I still look forward to a fully working VNAV update because the real one has it working, for the most part...

Edited February 28, 2018 by Shanwick

[Litjan]

I agree with Shanwicks assesment. We are looking to complete the FMC because we feel that it is part of the aircraft and if it is on the aircraft, it should be in our simulation and working correctly.

It is true that VNAV is not widely used in descent on the Classics - pilots use it as a "second opinion" and we like to watch the altitude deviation scale to give us an idea what the FMC "thinks" of our energy situation. It can provide a valuable "heads-up" in some situations. I used it frequently as a "socially compatible" reminder to my FO´s that he is way below profile. "Oh, the FMC thinks you are 10.000 feet low. Well, we both know it can´t calculate very well..." - Silence - FO dials in V/S -200 .

It is very rare that you get to fly an approach fully on LNAV and VNAV in real life - so you need to ad your local knowledge and guestimates to the descent calculation, something you can´t do well in the FMS. Yes, you can add an "expected" shortcut, but if you don´t pay attention and NOT get the shortcut, the plane will turn anyway - leading to a clearance violation.

The only airports I used to regularly fly VNAV into are ESGG and LHBP. They reliably use RNAV STAR and transitions. Everywhere else its FL CHG and V/S.

Jan

 

[sdflyer]

22 hours ago, Capt.Stanford said:

Guess I was misinformed, I'm starting to think that VNAV on the 737 (at least for now) is somewhat like an advisory system used on CRJ aircraft, I'm about to start training for my Instrument Rating here at University & I use flight simulators (X-Plane/P3D) along with Navigraph to help me practice SID/STAR procedures, so it is important for me the FMC has somewhat full VNAV functionality.

It's still a good plane anyways even if the FMC is not fully functional, hopefully IXEG will release an update soon. Exactly when we'll find out soon enough hopefully

When I got my IR I only had  6 pack, 1 CDI, paper charts, chronometer, stick, rudders, and throttle

[Dhruv]

9 hours ago, Litjan said:

The only airports I used to regularly fly VNAV into are ESGG and LHBP. They reliably use RNAV STAR and transitions. Everywhere else its FL CHG and V/S.

Jan

Jan, this may be the case in Europe, but the overwhelming Nextgen push in the US has been towards Optimized Profile Descent arrivals which essentially require accurate VNAV in order to fly. These procedures are VNAV-dependent to the extent that CRJ/ERJ operators often file ASAP reports due to not being able to comply with the procedures as published due to the Advisory VNAV being insufficient.

The overwhelming doctrine even at Southwest during the waning days of -300 operations was towards using VNAV on these arrivals more and more, despite Southwest being one of the more automation-resistant operators in the past due to a desire to maintain commonality with at one point a 3-family fleet.

[daemotron]

@Dhruv I think what Jan wanted to say that in the days back when he flew the B733, VNAV wasn't used a lot. As of today, there are also in Europe more and more airports trying to develop continuous idle descent profiles (I know at least we (Airbus) worked with EBBR on that). However that's far more complex than most people imagine; as you already touched the point let alone the different aircraft types & capabilities, but of course also the fact that there are some airports in Europe you hardly ever get into without holding (LFPG, EDDM in winter, ...) - there a type-specific VNAV profile would be wasted...