Dear Simmers,
I have a problem with my top of descent. I came to fast and to high on the runway ILS approach.
I can see that some pilots have top of descent marker on the primary display in airplane. Why I do not see it?
I configer flight plan in the simbrief and import it to the MSDU but there is no marker. I use FBY A32NX.
I have tried with calculator on the tablet but it gave me wrong top of descent. I came to high and to fast.
How do I know what is the best time to descent?
My question is also what is the right Flight level for your flight?
When you use the FBW you should have an T/D marker on your ND as well as in your Flightplan. Maybe you didn’t fill out everything. There is a little work to do after importing the Flightplan.
There is a rule of thumb to calculate your TOD.
Altitude/3=NM
E.g., FL300, Altitude where you wanna go, let’s say 3000ft-> 30000-3000=27000/3=90NM TOD Would add a little more, so let’s say 100nm. That’s how the calculator in the EFB works.
You will find your Cruise Altitude in your Flightplan. It depends on your route and weight. Inflight, you can find your max. recorded and optimum Altitude in the MCDU under the Button PROG.
Do you mybe know what instruction is in msdu to activate this marker?
Are there any youtube instructions for this?
Well, you have to go through the MCDU with the DIFRIPPS Departure seutup. With that you went through all neccesary parts, don’t forget something, and everything will be fine.
There are many YT Videos outta there. Just google a little and then you’ll find a lot.
Anyway, don’t know if that would fix it, because i neverfaced that problem since a while. I flown the fbw yesterday and as usual, i had my TOC/TOD
Times 3, not devided by.
Cut off three zeros and take it times 3. 100 miles for 27000 ft is excessive. 27*3 is what you want. And even those 80 miles is quite far out for an A320.
Guess there are more than one thumb rule. I found the other one, anyway it’s just a rule of thumb. Calculated by the FMS is far easier.
Well…yes….sure not divide……need some coffee 
I think the TOC/TOD marker is not present in Stable Version (the one I use). As far as I know, Experimental and Develope versions of the FBW, have such marker.
I am using latest stable version yes. I guess that is the problem.
The TOD marker is not displayed on the navigation display, nor is TOD in the MCDU at the moment for stable and also in the current developer version, it’s not there.
I think only the experimental has it at the moment.
Not even in the dev? Oh….ok……I use the exp since month, so never thought that
ATC has had issues with TOD and getting too correct RW, since release. The rule stated in the second post is correct and is excellent rule of thumb. If I am using the Navigraph FP, and import into 737 FMS, and then put in Star/sids correctly, it will show my TOD on the route if I zoom in enough. to see it clearly. I normally just start descent at 100 miles away from my final destination, if ATC is off, if on, I usually start at 90 miles regardless of what they say as it bogus in sim. Once I am within 10 miles of TOD, I change altimeter setting to the 1st point of the STAR altitude and keep changing it until I am on approach altitude, so plane get down to it. If short route to test something (RNAV Approach) I keep it set to the altitude on the chart for that route. If I fly higher, it gives me error in FMS when putting in altitude and waypoints. I am most likely doing it wrong, not RL pilot, but you cannot count on ATC in any of the sim I am aware of. Vatsim might be correct, but do not use them.