FMC Climb DIR/Des DIR

[Guest Bjorn Ghezzi]

Hello all,I would like just a clarification. It's a pure curiosity of mine.I noticed that these two functions although active on the FMC, do not seem to accomplish what they are supposed to as I have understood from the manual. I had a climb costraint on a SID of FL150B. I was climbing thru FL100 and had FL350 set in the MCP altitude window since I was cleared to climb directly to my cruise altitude by ATC. So I pressed the climb DIR LSK on the FMC climb page and executed it when prompted, but the altitude costraint was not deleted and the aircraft attempted to level off at FL150 by that specific fix. I just wanted to know to what extent these 2 functions are simulated int the current FMC setup. I gathered from reading the manual that these functions were implemented and worked.I tried the same on descent also, lower alt in MCP, costraint "at or above" between my current altitude and MCP selected, but the costraint was not deleted. I also pressed the MCP alt knob to delete the costraint but the plane still attempted to respect the costraint.Any info much appreciated. :-)Regards,Bjorn

[Guest Bjorn Ghezzi]

Ok, I went thru TRC lesson 4, and then tried again in the sim and figured that it works, but with "soft" costraints only, not those with the "at or above/at or below" restriction. I guess from the manual I didn't clearly understand this.Hope this might help somebody anyway. :-)Regards,Bjorn

[downscc 1,327]

The FMC doesn't model dual constraints, yet.

[Epikk 62]

Yup... already noticed this problem and already posted here about this, but got no response. Finally somebody else also noticed this...

[Tabs 2,790]

>The FMC doesn't model dual constraints, yet.I'll have to ask Vangelis, but I think you may be wrong there Dan... I'm pretty sure I remember us doing that in the 400F development.