CRJ v2 VNAV + LNAN (1000)

[aletri 0]

Without a doubt a big work has been done to overhaul the CRJ and bring that regional jet to a new life which I very appreciate.

Nevertheless there is some VNAV logic not working like it should:

 

- VNAV in cruise at TOD should not leave altitude until a lower altitude is selected !..once in VNAV descent must level off at any preselected altitude !

- VNAV "above constraints " in descent should be respected even if altitude preselector is set to lower altitude and continue after to the the preselected altitude.

- VNAV "below constraints" in climb should be respected even if altitude preselector is set to higher altitude and continue after to the preselected altitude.

 

- LNAV (white needles) during approach when ILS is captured should change automatically to NAV mode (green needles)

  

[michael-t 5]

Afaik, the VNAV pages of the FMS contain only advisory speeds for TOD calculation. Once the white asterisk shows up on the PFD, you have to manually descend by setting vertical speed. Automatic descent does not exist in the CRJ because it has no autothrottle.

 

See here:

Chucks CRJ700ER guide

 

Michael

[CRJay 483]

Coupled VNAV is available as an option. I believe it was standard on the 1000 and maybe some late 900s. These aircraft will have a VNAV button, and it practically functions like VNAV you might know from Boeing or Airbus, but you have to manage thrust yourself.

[Jack Vogel 2]

Descent is not a matter of the throttle, its a matter of the elevator   So this repetition about "advistory" doesn't apply, yes we need to control the throttle, but there's NO reason to justify it breaking altitude restrictions either going up or down IMHO.