Hi guys!Can you "speed intervene", i.e., select a manual speed while in vnav during a vnav non prec approach?I can't seem to get the software to do it.thanks!steveups

Click the speed selecton knob.Greg

As soon as I try to speed intervene with the speed knob while in vnav it drops out of vnav!

It drops out of VNAV PATH but it is still in VNAV SPEED.Michael J.

I must have a software bug... or something...it's all wrong...If i have a non prec approach setup in the fmc with correct stepdown altitudes and speeds... and I select vnav for the approach everything is fine.. but as soon as a hit the speed knob to speed intervene, the mcp drops out of vnav and into v/s mode. In the real airplane it will stay in vnav mode and the speed window will stay open so that you can manually override the speed in vnav for the apporach. Maybe this is just UPS 757/767 specific? Or my software is screwed up!Arghh!steve

What you describe seems normal behavior!!VNAV works on managed speed, which means your plane would have the optimum speed. If you change that speed to go higher or ower, you are not in managed mode anymore, but in a more traditional A/P mode.Maybe, the function of the managed speed depends on the specs of an airline.Francois

No. VNAV speed intervention is modelled in PIC. Though I don't know what the problem might be in this case - I have never had any problems with the spped intervention.Regards,Karl

I agree. I wasn't first sure but I tried again. Speed intervention works fine for me, aircraft remains in VNAV PATH.Michael J.

see if that makes a difference.thanks for the replies guys.steve

For kicks, try changing your target speed on the DESC page of the FMC. Does that work for you?J

Hmmm, kinda tricky using VNAV in an approach environment in the first place.It is easier (and recommended) using heading select and FLCH outside the FAF, and VS/heading inside the FAF with straight speed select.Timothy

when the end of the runway is identified on our jepp approach plates and fmc database, we build vnav descents for the non-prec approaches.we also speed intervene after selecting vnav at the final approach fix inbound.steve

SteveUPS shoots VOR/Non-precision with the ND in MAP or VOR?Timothy

I re-installed the software and I still can't speed intervene in vnav and have it stay in vnav path. Oh well.steve

Very strange. Can you post screenshots? Is there any chance your joystick or throttle is noisy?Jon (KSEA)