VNAV mode

[edpatino 1,960]

Hi. I don't know if this have been discussed before, but it seems that neither in v1.0 nor v1.1 the A/P VNAV mode is working. When introducing altitudes on the FMS the values are not respected and you have to play with the ALT SEL and VS modes to set de desired altitudes while on route.

If that is true to everybody, could someone at Carenado confirm if VNAV will be implemented at some point in future versions.

Cheers, Ed

[barrel_owl 304]

Hi. I don't know if this have been discussed before, but it seems that neither in v1.0 nor v1.1 the A/P VNAV mode is working. When introducing altitudes on the FMS the values are not respected and you have to play with the ALT SEL and VS modes to set de desired altitudes while on route.

If that is true to everybody, could someone at Carenado confirm if VNAV will be implemented at some point in future versions.

Cheers, Ed

Do you have NAV activated on your AP?

[edpatino 1,960]

Do you have NAV activated on your AP?

 

Yes, with NAV activated it follows the lateral route.

Cheers, Ed

[barrel_owl 304]

Yes, with NAV activated it follows the lateral route.

Cheers, Ed

Well, as I explained in another thread, according to Carenado, it should also follow vertical navigation, which it does here.

VNAV is not officially implemented (the VNAV button is inoperative), however, setting altitudes in the FMS and then activating NAV on the AP makes the aircraft climb/descent in VNAV mode.

 

Another possible explanation is that you set a VS. If you did so, VS overrides VNAV. Try again. Set a target altitude, click on ALT SEL, set altitudes on the FMS and see what happens.

[edpatino 1,960]

Well, as I explained in another thread, according to Carenado, it should also follow vertical navigation, which it does here.

VNAV is not officially implemented (the VNAV button is inopertive), however, setting altitudes in the FMS and then activating NAV on the AP makes the aircraft climb/descent in VNAV mode.

 

Another possible explanation is that you set a VS. If you did so, VS overrides VNAV. Try again. Set a target altitude, click on ALT SEL, set altitudes in the FMS and see what happens.

 

Ok, as I remember I have not set the VS when experimenting with the FMS vertical mode. Anyway, I'll recheck tomorrow with NAV mode to see what happens here.

Thanks for your advise.

Cheers, Ed

[barrel_owl 304]

I will test again too. Not 100% sure, but when I tried VNAV, it seemed to work this way.
 

[edpatino 1,960]

I will test again too. Not 100% sure, but when I tried VNAV, it seemed to work this way.

 

 

I'll post my results here tomorrow.

Cheers, Ed

[lthendrix 25]

if I understand it its the nav key on the fms not the ap that needs pressing after takeoff

[edpatino 1,960]

Hi, these are my results for Vertical Control mode. Seem to me that's not working well.

 

The FP (generated by the P3D default flight planner) shows that the aircraft should be at 12,000 ft crossing SZW VOR.

 

 

AP is ON, NAV/HSI is in GPS mode (green) and NAV mode indicates that NAV is CAPTURED.

 

 

NAV/GPS switch selector in GPS position. The aircraft is following the lateral route correctly.

 

 

Supposedly the aircraft should have leveled-off at 12,000 ft, but VS is still indicating 1,200 fpm and altitude is higher than 12,000 ft and climb continues...

 

 

Any comments are welcome.

Cheers, Ed

[barrel_owl 304]

Supposedly the aircraft should have leveled-off at 12,000 ft, but VS is still indicating 1,200 fpm and altitude is higher than 12,000 ft and climb continues...

 

Hi Ed,

it seems to me that you have not ALT SEL selected on your AP.

Other question. Which is your target altitude?

 

[edpatino 1,960]

Hi Ed,

it seems to me that you have not ALT SEL selected on your AP.

Other question. Which is your target altitude?

 

 

Hi, you're right, ALT SEL is not selected (did that on purpose). The drill shown in pictures was to try leaving the FMS do all the work, as supposedly the NAV option could connect the AP to the FMS and control both the lateral and vertical profile, but it seems it is not controlling the vertical path.

The first target altitude was 12,000' as you could see in the FMS screen, but well before getting to the SZW VOR, the aircraft climbed up to 13,400' and continued the climb (as VS was still around 1,200 fpm, with no signs of leveling-off).

Please, if you have some time, try it by yourself and let me know if you find the way to have the FMS control both lateral and vertical profile of the flight plan.

Cheers, Ed

[barrel_owl 304]

The first target altitude was 12,000' as you could see in the FMS screen, but well before getting to the SZW VOR, the aircraft climbed up to 13,400' and continued the climb (as VS was still around 1,200 fpm, with no signs of leveling-off).

Yes, I can see that you set a target altitude of 12,000 for the waypoint SWZ on your FMS. But, which target altitude did you set on your altitude selector? It is just on the right of your MFD 640.

That's a key question and I can't see this information on your screenshots.

 

Sorry if (as usual) I did not make myself clear. I hope you appreciate my non-native English speaker efforts. :-)

[edpatino 1,960]

Yes, I can see that you set a target altitude of 12,000 for the waypoint SWZ on your FMS. But, which target altitude did you set on your altitude selector? It is just on the right of your MFD 640.

That's a key question and I can't see this information on your screenshots.

 

Sorry if (as usual) I did not make myself clear. I hope you appreciate my non-native English speaker efforts. :-)

 

In fact I didn't set any altitude there (right there where you said), just because I was trying to confirm that the FMS would control the vertical path. Do you suggest me to set an altitude level of, let's say 12,000 ft, and then increasing it continually as the flight develops, of just to select from the beginning a final altitude level, which in this case would be 25,000 ft?.

No problem, we both are not english native language speakers. If you're in Brazil, we can probably talk a little bit of portunol. LOL.

Thanks so much, Ed

[barrel_owl 304]

Yes, the aircraft definitely needs a target altitude to "chase". Using VNAV of VS is a pilot's option.

I suggest you to repeat the same flight and to set a target altitude this time, for example 25,000 (which I believe is your cruise altititude), without any VS. Now, if VNAV works, the aircraft should reach 25,000 exactly at LEGGT and cross the previous waypoints at the altitude you set on your FMS (following your screenshot, SZW at 12,000 and HEVVN at 18,000).

Setting a VS should overide VNAV. So do not set any VS or just set it right after the takeoff until you are cleared by the ATC, then climb with VNAV and see what happens.

[edpatino 1,960]

Yes, the aircraft definitely needs a target altitude to "chase". Using VNAV of VS is a pilot's option.

I suggest you to repeat the same flight and to set a target altitude this time, for example 25,000 (which I believe is your cruise altititude), without any VS. Now, if VNAV works, the aircraft should reach 25,000 exactly at LEGGT and cross the previous waypoints at the altitude you set on your FMS (following your screenshot, SZW at 12,000 and HEVVN at 18,000).

 

Setting a VS should overide VNAV. So do not set any VS or just set it right after the takeoff until you are cleared by the ATC, then climb with VNAV and see what happens.

 

I'll do. I'll report back here.

Thanks again.

Cheers, Ed