LatinVFR forums

Hello, when do I know when I have to initiate descent? So if the constraints are in the waypoints I can go into Managed Descent for the Descent Marker. It should work thanks to VNAV. However, if the constraints are not included, I have no way of adding the constraints manually. So I then have to calculate the ToD myself. The problem with that is that I can't use any fix info in the MCDU to see the distance. Could someone please explain to me how I can easily determine the ToD? So it's not the calculation but how I see on the plane when the right time is?

We are going to release an avionics update on the A32x family in the coming months, after its been implemented and tested on the A330neo. The CDU side will also be overhauled. that's coming. Our apologies in the meantime

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 2:55 pm

We are going to release an avionics update on the A32x family in the coming months, after its been implemented and tested on the A330neo. The CDU side will also be overhauled. that's coming. Our apologies in the meantime

Ok, thank you very much for this information. But how can I determine the ToD until then if I calculate it myself? I would then have to calculate backwards in the flight plan to get the correct distance to the ToD or is there an easier way?

AviationLife wrote: ↑

Sun Oct 22, 2023 3:09 pm

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 2:55 pm

We are going to release an avionics update on the A32x family in the coming months, after its been implemented and tested on the A330neo. The CDU side will also be overhauled. that's coming. Our apologies in the meantime

Ok, thank you very much for this information. But how can I determine the ToD until then if I calculate it myself? I would then have to calculate backwards in the flight plan to get the correct distance to the ToD or is there an easier way?

TOD depends largely on the constraints in the STAR, and other airport environment situations.

I just pulled it from google if you want a rule of the thumb: " The correct calculation is to MULTIPLY the difference in thousands of feet between cruise altitude and pattern altitude by 3. Thus, if you are at FL350 and your destination airport's pattern altitude for your aircraft is 2,000 feet, the calculation would be as follows: (35 - 2) X 3 = 99 miles from the airport to TOD"

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 3:22 pm

AviationLife wrote: ↑

Sun Oct 22, 2023 3:09 pm

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 2:55 pm

We are going to release an avionics update on the A32x family in the coming months, after its been implemented and tested on the A330neo. The CDU side will also be overhauled. that's coming. Our apologies in the meantime

Ok, thank you very much for this information. But how can I determine the ToD until then if I calculate it myself? I would then have to calculate backwards in the flight plan to get the correct distance to the ToD or is there an easier way?

TOD depends largely on the constraints in the STAR, and other airport environment situations.

I just pulled it from google if you want a rule of the thumb: " The correct calculation is to MULTIPLY the difference in thousands of feet between cruise altitude and pattern altitude by 3. Thus, if you are at FL350 and your destination airport's pattern altitude for your aircraft is 2,000 feet, the calculation would be as follows: (35 - 2) X 3 = 99 miles from the airport to TOD"

I understand that calculation. My problem is that I can't see the distance to my calculated ToD in the MCDU because I can't use Fix Info yet. I would have to add up the distances between the waypoints or roughly estimate it on the navigation display. I wanted to know if there was an easier way.

There is supposed to be a TOD currently, you don't see it?

AviationLife wrote: ↑

Sun Oct 22, 2023 3:28 pm

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 3:22 pm

AviationLife wrote: ↑

Sun Oct 22, 2023 3:09 pm

Ok, thank you very much for this information. But how can I determine the ToD until then if I calculate it myself? I would then have to calculate backwards in the flight plan to get the correct distance to the ToD or is there an easier way?

TOD depends largely on the constraints in the STAR, and other airport environment situations.

I just pulled it from google if you want a rule of the thumb: " The correct calculation is to MULTIPLY the difference in thousands of feet between cruise altitude and pattern altitude by 3. Thus, if you are at FL350 and your destination airport's pattern altitude for your aircraft is 2,000 feet, the calculation would be as follows: (35 - 2) X 3 = 99 miles from the airport to TOD"

I understand that calculation. My problem is that I can't see the distance to my calculated ToD in the MCDU because I can't use Fix Info yet. I would have to add up the distances between the waypoints or roughly estimate it on the navigation display. I wanted to know if there was an easier way.

Hi,

firstly I would like to say that ToD should be shown even without constraints because 50 feet above runway threshold should be used instead. I will check this behavior in the a321.

About the "workaround" if you calculate the ToD yourself then you can use distance to DEST value on LEGs page, last line

Kind regards
Sink-rate

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 3:30 pm

There is supposed to be a TOD currently, you don't see it?

I see that. But if I have a constraint beforehand that is not in the waypoint, the ToD marker won't fit because I have to sink first. With Fix Info I could just draw a circle with the corresponding radius, but that's not possible yet. And that's exactly what it's all about for me. So I have no choice but to add up the distances between the waypoints to figure out when I need to sink.

Sink-rate wrote: ↑

Sun Oct 22, 2023 4:08 pm

AviationLife wrote: ↑

Sun Oct 22, 2023 3:28 pm

RicardoLVFR wrote: ↑

Sun Oct 22, 2023 3:22 pm

TOD depends largely on the constraints in the STAR, and other airport environment situations.

I just pulled it from google if you want a rule of the thumb: " The correct calculation is to MULTIPLY the difference in thousands of feet between cruise altitude and pattern altitude by 3. Thus, if you are at FL350 and your destination airport's pattern altitude for your aircraft is 2,000 feet, the calculation would be as follows: (35 - 2) X 3 = 99 miles from the airport to TOD"

I understand that calculation. My problem is that I can't see the distance to my calculated ToD in the MCDU because I can't use Fix Info yet. I would have to add up the distances between the waypoints or roughly estimate it on the navigation display. I wanted to know if there was an easier way.

Hi,

firstly I would like to say that ToD should be shown even without constraints because 50 feet above runway threshold should be used instead. I will check this behavior in the a321.

About the "workaround" if you calculate the ToD yourself then you can use distance to DEST value on LEGs page, last line

Kind regards
Sink-rate

All right, then I'll do it that way in the future and hope that the Avionic update comes and works in the 330-900 so that you can also implement it in the a321.

@Sink rate, by the way, I answered you in the topic about the A330-900 about the engine off and trim tank

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