Still when in V/S mode the autopilot should not be able to change the vertical speed, only in the managed modes will the autopilot reduce rate of descent to adhere to MCDU speed constraints. in V/S mode the autopilot does just that, maintain the selected vertical speed without advanced functions.
250 / 10.000 ft is relatively common all over the world (maybe not in US?). Neither do you want to fly much faster during a normal approach at that point. 30 nm at 250 kts and 10.000 ft for a 3 degree descent path is a good reference from energy management perspective.
I guess it depends on what’s the priority here that the autopilot uses. I can’t think of any way that’s physically possible to set a high descent V/S while maintaining a slow airspeed. I think if it’ prioritises V/S, then the airspeed limit will have to be sacrificed, isn’t it?
This is why I never really use V/S. I prefer to do approach using Track and Flight Path Angle, especially on non-precision approach like RNAV. Otherwise, if I don’t want to control my descent angle, I just leave everything on managed mode, and let it descent on its own. I always get to my ILS intercept altitude everytime, even following the default ATC instructions.
I only need to hit the speed brakes sometimes if I want to speed up my descent.
The autopilot has no priorities, V/S or FPA are “basic” modes, when active the autopilot maintain the selected V/S or FPA and levels off at the pre-selected altitude. It disregards all else, MCDU altitude and speed constraints are disregarded. The autothrottle might still (try to) maintain the correct speed when in managed mode. When within the normal flight envelope (not over speeding / stalling) the autopilot will remain the selected VS / FPA no matter what…
This is what I meant by “priorities”. Sorry if I confuse you with my incorrect terminology. To me, when a system is activating a certain mode, while disregarding something else. That’s what I call “priority”, so in this case by my definition, basic modes such as V/S and FPA takes priority because they are active and disregards MCDU constraints. Without this priority set up in the computer. It will always be in conflict between the flight computer and the “basic” modes.
I am talking about computing terminology, hence I use the word “priority”.
I get your point, however in V/S or FPA the MCDU constraints are NEVER taken into account so in my mind there is no priority as there is only one option . Anyway, we mean the same thing. On planes I’m flying there are 3 levels, the most basic level are PITCH and ROLL modes, then there is HDG, V/S, FPA and FLCH and last there is LNAV / VNAV, for the latter the FMS needs to be properly set-up, all other “levels” have nothing to do with the FMS.
Same on the Airbus since the managed modes are basically the same as LNAV / VNAV on other aircraft types and open climb / descent is essentially FLCH mode. I guess the difference with Airbus is that when in managed climb or descent mode it is still possible to go out of managed speed? You can’t do that on every aircraft type, the speed window blanks as part of the VNAV mode. Maybe I’m wrong, I’m not that familiar with the Airbus.
A320 instructor is completely inaudible English is Aviation Standard, but a guy who narrating A320 speaking too fast and problems with understating what he was saying.
Could somebody please tell me how to jump between NAV mode and HDG mode in the A320?
I understand it in the planes with Garmin autopilot… very simple: just push the HDG or the NAV button.
But in the A320, it seems to be a little different. I can engage HDG mode… but how can I jump to NAV mode (or the other way around)?
When you push the heading button (cursor showing up arrow) it will engage Managed heading (NAV) mode. The heading will display (- - -) without any numbers. and your FMA in the PFD will show NAV.
But if you pull the heading button (cursor showing down arrow) it will engage Selected Heading (HDG) mode. The heading will be shown in the display. and your FMA in the PFD will show HDG.
Note that you need an actual flight plan with a flight path to be able to use the NAV mode.
May I ask what the problem is when the A320 autopilot neither takes the NAV nor the HDG mode?
When I preplan an IFR flight in the world map, then start on the runway and take off, the plane is in NAV mode, and all the waypoints are correctly shown in the display.
But engaging the autopilot after takeoff does not make the plane fly to the next waypoint. The plane just starts to head left or right, and the angle gets steeper and steeper, so the plane goes into a curve faster and faster until it breaks.
When this happens, I also can’t go into HDG mode. The autopilot just does not care.
Why is that?
Autopilot perfectly uses thrust, and also altitude… but it ignores HDG (or NAV) and just starts spinning left or right until the plane breaks ^^.
Why?
Oddly, this does not happen always. From one airport it worked PERFECTLY fine with NAV mode.
From another, not at all, the autopilot ignores the waypoints (NAV mode) AND the HDG mode and the plane just stars spinning.
What am I doing wrong here?
Probably nothing. Some settings affect this though.
Do these steps:
With the sim running, if you are on the start up screen, from the top heading, select “Options”, or if you are already in the sim, press “ESC” on the keyboard.
Under “General”
Set “Flight Model” to “Modern”, not “Legacy”.
Under “Assists”
Set all “Piloting” assists to “Off”
When you are in the sim, from the “winged” sim icon, Open AI Control (icon to the right of the yoke icon), and ensure that “Control Aircraft” is “Off” (button placed to the left).
Next, and quite important, is to add deadzones to each axis for all your controllers. Approximately 5% should be enough, but there have been instances where significantly more was needed.
Do not assume, even if you know how you had these already set, ensure these are this way now.
The last few updates did change some user settings.
Thank you. I think the deadzone of the controller was the problem. I did not have any deadzone applied. Now after I did that, it seems to work so far. Haven’t tested it much yet, but it looks good.
Thanks a lot!
Funny that only the A320 had a problem with this. None of the other planes did…
If I may ask something else: When I preplan an IFR flight in the worldmap and then fly that, after a few minutes, ATC often tells me that I have to reset the transponder because the transponder seems “malfunctioning” and ATC want to me enter Squawk again.
How do I do that if that happens?
Is there a keyboard button to reset it?
Because when you ignore ATC on that, it cancels the IFR flight after a while.
Seems also only happening in the A320 (and sometines the Cessna CJ4). Never happens with the Garmin planes like the TBM 930 for example.
How to solve this Squawk problem when ATC complains?
Yes ATC would do that as they can’t identify you in the sky. That number is assigned to your blip on their radar.
The transponder on the A320 is beside the throttle to the right.
You must do three things!
Punch in the code, turn the transponder to auto or on (upper left switch).
bottom right goes to TARA (Traffic Advisory and Resolution Advisory) your collision avoidance system
(It doesn’t really do much in the sim but it does IRL)
Just to add to the context, this transponder malfunction occurs when you start your flight from the runway. The reason is that when you start your flight, the squawk code is set to the default 7000. Since you’re in IFR, the squawk code needs to be unique.
You can get this squawk code entered automatically when you start the flight at the gate. Because you would go through the process of requesting IFR clearance, which the ATC will assign you the squawk code and it will be entered automatically once you acknowledge that clearance. Since you start on the runway, this IFR clearance never happened, so when you take off you took off with the wrong squawk code. Hence why the ATC always requires you to reset transponder to the assigned squawk code.
Thanks @TheSevenflyer and @Neo4316 . I will try that.
What is odd is that the MSFS2020 ATC has this problem indeed when starting from the runway like @Neo4316 said. BUT it seems not to happen with most planes. Never had it with the Longitude, or the TBM930, or others. The transponder works fine with these when starting from the runway with a preplaned IFR flight.
But it does not with the A320 and also not with the CJ4. That confused me quite a bit.
What I do if starting from a runway and not from the gate is scroll back through the ATC message log. Even though you start from the end of the runway, the IFR clearance including initial alt and transponder code is there. I take a second to set those before blasting off.
. Anyway, we mean the same thing. On planes I’m flying there are 3 levels, the most basic level are PITCH and ROLL modes, then there is HDG, V/S, FPA and FLCH and last there is LNAV / VNAV, for the latter the FMS needs to be properly set-up, all other “levels” have nothing to do with the FMS.
