I just purchased the ATR from marketplace and am exploring/trying it out in various ways. The one thing I haven’t been able to wrap my head around is how to do VNAV climb/descent. I haven’t done VNAV in any other aircraft before either so this is probably me just not knowing what I’m doing.
I’ve entered a route in the FMS. I’ve also entered arrival details (STAR + runway/ILS).
I can see all the waypoints added to the route with altitude constraints.
At this point, from looking at various youtube videos I would expect a TOD marker on the ND. There is none, just the route plotted. Cleared to descend to X ft, I select the new altitude and hit VNAV button. The plane goes into an immediate dive around 6000ft/min. Ignoring any constraints.
The PFD never really display the VNAV PATH (or any other VNAV indication) either but rather “ALT*”.
I’m probably missing one or several crucial steps setting this up, can anyone point me in the right direction or guide how to use VNAV on the ATR?
Hmmm so where to begin… first thing you want to do before touching FMS is choose your cruising alt with the knob selector. Then hit IAS and then VNAV and NAV buttons. On your PFD it should show in blue LNAV and VNAV IAS. Now on to the flight programming in the MCDU. Enter your flight plan as you normally would. Make sure there are no discontinuities and if there are any waypoints with the constraint of WINDOW… I clear those constraints, it seems to make the VNAV PATH go crazy. I also check the FAF… if it has the constraint of 3000A for example, I change it to 3000. Makes the TOD more accurate. Check the PERF INIT make sure your cruising ALT is correct… VNAV also make sure cruising ALT is already set to whatever you chose in 1st step. Make sure you long press your weights… then confirm this on the MFD perf page as well as SEL Speed TGT AUTO to the left of the PFD. I found if you don’t select the cruising altitude with the knob before messing with the MCDU, it can cause errors later (including the missing TOD marker). Now you’ve been cruising in ALT mode and ready to descend… you are approaching the TOD marker eventually the magenta box appears on the PFD alt tape… when this box turns on then you can reduce your altitude selector knob to FAF but not before. Now hover your cursor over the VNAV button and wait to reach the TOD marker. Once you get to the TOD, you will see the magenta box drop down the tape a bit… now press the vnav button and you should enter VNAV PATH mode. If instead it says ALT* on the PFD then click VNAV again and it should switch to VNAV PATH mode… Make sure to throttle back to almost but not quite flight idle and ride the path down to FAF. When you reach FAF switch over to VOR/ILS1 and it will automatically enable approach mode… check that you have captured the LOC and GS, change your alt and hdg to go around. Flaps, gear, power mgt to TO. If you seem to be losing the glideslope and are too low, hit the ALT button until you cross the diamond then hit APP again.
Also sometimes the magenta box does not appear at all until you reach TOD… and when it does, it is already showing descent… when this happens don’t panic. Just lower the altitude selector ~1000 feet and click VNAV to start the descent… make sure the VNAV PATH is ok, then reduce your selected altitude to FAF. You really got to go to th flight plan and make sure it is easy for the plane to read… A lot of sids, stars, etc can be messed up in the database.
I’m struggling to make VNAV work also.
So, you’re saying to do descent from cruise altitude to your approach fix in VNAV, not VS? It seems to me that as I approach the TOD circle, it starts to move away towards the airport? So I get to my IAF and then, what? Hit VNAV again? Dial down to the mins and then hit VNAV again?
I flew the ATRs back in the 90s with none of this stuff, but I have a Lot of 737 time and VNAV appraches that don’t quite work this way.
I meant to specify a VNAV APP, not an ILS. The equipment works well for ILS.
How do I fly a VNAV approach from cruise through the approach in LNSV/VNAV?
Ok, well I just got it to work. VS down to IAF from cruise altitude. Dial down to 100 feet abv airport elevation. Select VNAV, got VNAV PATH! A VNAV approach the virtual passengers survived.
You can do VNAV from cruising altitude… Just watch the alt tape in your PFD… don’t change your selected altitude until you see the magenta box and the TOD won’t move away from you. Then change your altitude to IAF or FAF… and when you arrive at TOD, you will see the magenta box drop down the tape… THEN you activate VNAV PATH mode. Sometimes the magenta box appears only after you’ve arrived at TOD… then what you do is lower your alt about 1000 feet, hit VNAV until it engages, then reduce the selected alt even further to IAF or FAF.
Fantastic description of these steps, exactly what I have been looking for, thank you, this has completely opened up the entire ATR Nav system for me
ShakyJake
This drives me nuts. 80% of the time I can make it work, but sometimes I just get stuck where it kicks back to Alt* right away. I can spam vnav, and it just kicks right back to alt*. I can’t figure out why. I’ve done all the steps correctly AFAIK. I even have the flight path indicator on the PFD, and I can manually follow it down using VS mode, but try and click VNAV, and nope. Just right back to Alt*.
Ten miles or less to reaching the TOD point on the PFD will appear a vertical scale (may be almost over the TOD). Then, you can set the desired altitude (can be the IAF, the runway, or any other). When the pink square go down, press the VNAV button. That’s all.
This seems to be the right answer. The problem arises if you aren’t cleared to descend before the TOD marker passes. If you pass this point it seems you simply can’t use VNAV after that, Shouldn’t the VNAV just recalculate the required descent angle and continue? I know you can dive down to get back on profile and sometimes it will work, but is this how it is intended?
I suppose you need to force it to recalculate, by doing a DIR or something. It’s the same as with lateral navigation. If you get too far from the magenta line the aircraft will not know what to do unless you update your routing. It’s the same with vertical navigation.
Edit: I don’t know anything about the ATR, this is just common sense.