Managed Descent Behaviour

[Philippe TORNE]

Using 1.0.7. The aircraft has an incorrect behaviour during managed descent (DES).

According with the documents, the first part of the descent (from the TOD to the first constraint) should be an idle path. The FMA should display THR DES or THR IDLE | DES | NAV and the A/THR should go the IDLE (or very slightly above if necessary). This is not the case with this product. The aircraft is always descending in MACH/SPEED with a very shallow path (almost never more than -1500ft/min) resulting in a high amount of thrust. This leads to a very long descent and a very high fuel consumption. Could you please fix this as quick as possible thanks.

 

Edited Wednesday at 01:38 PM by Philippe TORNE

[jaybird]

"Managed" descent means it is calcuating a veritical path, not that it is following some fixed throttle behavior, if you initiate descent early it will follow a shallower path, the small green dot on the altitude tape shows that it is above/below/on that path. Behavior has seemed correct in my flights. 

 

[Philippe TORNE]

13 minutes ago, jaybird said:

"Managed" descent means it is calcuating a veritical path, not that it is following some fixed throttle behavior, if you initiate descent early it will follow a shallower path, the small green dot on the altitude tape shows that it is above/below/on that path. Behavior has seemed correct in my flights. 

 

May I sugest you to read my message again and carefully ?

[magret2canard]

20 hours ago, jaybird said:

"Managed" descent means it is calcuating a veritical path, not that it is following some fixed throttle behavior, if you initiate descent early it will follow a shallower path, the small green dot on the altitude tape shows that it is above/below/on that path. Behavior has seemed correct in my flights. 

 

Of course. But the path should be calculated to descend with idle thrust until the first constraint, like Philippe explained 🙈

I will be surprised if the behavior seemed to be correct on your flights because it's definitely not on mine as well

[jaybird]

Either one of you aeronautical engineers, I know I'm not, so where do you get off with dogmatic assertions about what "should" be the behavior?  I have a sim that predicts how much fuel is needed in a flight, and you know, that amount seems to work, I arrive at my destination. And I have a sim that predicts what TOD is, and when I descend there, and have the flight computer control it, you know what, I arrive at the IAF to my approach at the correct altitude.  To this amatuer that means its working pretty well.  I have no interest in further debate on the matter...

 

[ThorCoolguy]

Presumably they're reading the publicly available flight manuals for reference, not making "dogmatic assertions about what 'should' be the behavior."

 

This is a simulation of a real airplane. There is plenty of publicly available data on this real airplane and you don't have to be an aeronautical engineer to find it. If the simulator doesn't behave like the publicly available data says it should, that means our product (for which we paid a bunch of money) isn't behaving as advertised, and we have every right as customers to respectfully suggest that it be fixed.