T/D Displayed but aircraft doesn't engage VNAV Desc

[sgreen91 182]

I've been trying this flight KDSM - KDFW.  Here is the route:  KDSM DSM J25 DOSOA COODY HITUG BRDJE3.HITUG KDFW

A couple of issues.  The waypoint ROCKZ that is part of the BRDJE3 star looks like noodles all over the place.  So I delete the waypoint and the plan looks ok.

The second issue is there is a crossing restriciton of 11,000 at STONZ so the FMC has a TOD some miles out.  It reaches TOD and then says TOD is another 86 miles out which puts me way past the airport missing all restrictions on the star.

Could somebody test this to let me know where I'm doing this incorrectly.

[sgreen91 182]

Well I did the flight along the star again but this time deleted the VECTOR leg and left a discontinuity between the end of the STAR and RWY Approach.  I would guess it reaches TOD but must see the long line for VECTOR and decides not to descend.

 

[Meekg 86]

You need to fly this airplane, please do not rely on the VNAV.
There are definitely some issues with VNAV, which we will try to address but if you talk to any MD80 pilot they'll tell you the real VNAV is equally nearly unusable.

[Ugo 4]

Hello Folks

after v 1.0.4 setup I've noted (three flights) that I'm not able to engage VNAV Descent. T/D is correctly displayed on the Route. I armed clicking (on the descend altitude i want to reach) with sx button of the mouse, but once reached the T/D the aircraft remains at Cruise altitude without descending. The T/D green point disappears without descent. The magenta indicator of vertical profile doesn't appears at all. I must descent in V/S.

Before the new version everything was ok any suggestions to quickly solve it?

[Patco Lch 1,465]

Wonder about this myself. Seems it takes the VS wheel to start the decent. Sometimes clicking the VNAV button twice at TOD works.

[Nightliner76 1]

Same here.

[DaveCT2003 1,820]

Which version of flight sim software are you using (each of you please).  Works fine for me in P3DV4.2.

Many thanks.

 

[riftin11 2]

Good morning,

I've had an issue where the Maddog doesn't calculate a T/D if the route has any discontinuities in the STAR. For example, yesterday I flew KATL-MBPV using the RNAV28 arrival in MBPV. I loaded the flightplan from PFPX, there was a discontinuity in the route symbolizing vectors- which I cleared, however the FMC didnt calculate a T/D, just listed an end of decent which was the airport itself. I had to descent with the DES DIR feature. Is this a bug or am I doing something wrong?

[Patco Lch 1,465]

P3DV4.2

Edited March 5, 2018 by PATCO LCH

[Senchai 24]

I dont want to highjack this topic. I expereinced something like this too, but im still on 4.1... Would have a vid abou about it it helps.The thing is, im not sure i did something wrong maybe. I had this happen twice now. Maybe something else though, if so i can make extra topic if needed.

I had the T/D marker too, and i had a lower alt selected as well. When near tod i went into the FMS to insert the winds. I saw the yellow EXEC light light up and hit it. Both times i did this near tod the descent didnt automatically start.

Related/unrelated? User error?

Why i think about user error is that i think ive read something in the manual about this happening. That one should doublecheck eventual done changes in the route while inside FMS pages (wich can be seen when the EXEC light lits up without apparent reason)Also, both tims when this happened i could not get on the VNAV path anymore. It as basically heading  mode / v/s after this point bec nothing seemed to work anymore as i expected it. Vnav started descent even below an altitude, and didnt stop anymore even a higher alt is dialed in etcetcetc.

Edited March 6, 2018 by SaenchaySor

[Mad_X 12]

According to the devs it is a known topic with certain STAR layouts. They are working on it. 

[Wothan 173]

I have seen this twice now.

I got withing 10 nm from TOD, but did not get an FMS message to reset my altitude. Instead the TOD moved 93 nm further out and I had to revert to Vertical speed descend mode.

 

FinnJ

[Irishcurse 234]

1 hour ago, Wothan said:

I have seen this twice now.

I got withing 10 nm from TOD, but did not get an FMS message to reset my altitude. Instead the TOD moved 93 nm further out and I had to revert to Vertical speed descend mode.

 

FinnJ

I had similar but only when importing  a flight plan including the STARS. If I enter the flight plan by hand I have no issues. If what you are describing is you have a TOD and just as you approach the TOD the FMC gives a new one. That was my issue

[Wink207 78]

On 2/22/2018 at 1:49 PM, Meekg said:

You need to fly this airplane, please do not rely on the VNAV.
There are definitely some issues with VNAV, which we will try to address but if you talk to any MD80 pilot they'll tell you the real VNAV is equally nearly unusable.

+1

[DaveCT2003 1,820]

4 hours ago, Wothan said:

I got withing 10 nm from TOD, but did not get an FMS message to reset my altitude.

I've actually never seen this message as I have the new altitude in and armed well before then - depending on ATC coverage that is.

Best wishes.