Some issues or just me ?

[maniamcool 75]

Hi all, 

 

First of all I want to say congratulations PMDG, the aircraft is superb and I'm loving every second with it!

 

There are some quirks however, it might be a case of RTFM of which I have been doing since yesterday but this is really bugging me and I hope to get some insight here. 

 

1. Aerodynamic shake + sound

 

Is it supposed to sound like the aircraft is shaking violently as if it's on a takeoff roll?

 

I ask this because I had recently tried to take-off on a fully loaded -400ER from YSSY 16R. After rotating, the aircraft became to generate this extremely violent shaking sound which sounded like it was still hurtling down the runway. I guess this was due to the heavy load on the aircraft + the large elevator force during the initial climbout?

 

The same sound was also generated when I flew through some thunderstorm clouds and deliberately sent the aircraft through some severe chop. 

 

2. VNAV behaviour on descent 

 

Does the autopilot intercept VNAV PTH from VNAV SPD automatically when the glide path is intercepted on descent?

 

This used to work on the 777 when I'm off the descent path and vnav reverts to VNAV SPD. Adding some drag to increase the rate of descent in VNAV SPD would correct the path and it would go back to VNAV PTH once the path is intercepted again. This however did not happen on the 747 for me and I would like to know if it is just one of the limitations of the Queen.

 

Would appreciate any input  :smile:

 

 

[jasoncardeira 30]

I did a flight yesterday, and talking about the descent path, it looks to me that it's the same or almost the same as the NGX: if you're off of the descent path, the VNAV reverts to VNAV SPD that's correct, and when you correct it by adding drag, when you're close to your descent path, the VNAV reverts again to VNAV PTH (just like the NGX or 777).

 

If not, maybe there's another factor for that to happen (passing a waypoint that requires a steep descent for the next waypoint maybe, and the VNAV will continue in SPD mode in this conditions)

 

For me there's no problems, it behaves like the other PMDG heavies

[maniamcool 75]

I did a flight yesterday, and talking about the descent path, it looks to me that it's the same or almost the same as the NGX: if you're off of the descent path, the VNAV reverts to VNAV SPD that's correct, and when you correct it by adding drag, when you're close to your descent path, the VNAV reverts again to VNAV PTH (just like the NGX or 777).

 

If not, maybe there's another factor for that to happen (passing a waypoint that requires a steep descent for the next waypoint maybe, and the VNAV will continue in SPD mode in this conditions)

 

For me there's no problems, it behaves like the other PMDG heavies

 

Yeah that's what I would expect from the VNAV, However in my case the VNAV only reverted back to VNAV PTH when I descended to 3000 feet* (An altitude constraint on the STAR I was descending on) and leveled off before that point. 

 

It might be that I was adding considerable amount of speedbrakes as the aircraft was descending on VNAV SPD, could this have caused the aircraft to "miss" the path and continue descending below VNAV PTH until an altitude constraint?

 

I remember reading somewhere that adding too much speedbrakes might cause the VNAV calculations to go off.. Didn't experience this myself personally with the 777 though. 

[jasoncardeira 30]

The aircraft should revert to VNAV PTH when you're close to the descent path. Adding the speedbrakes in VNAV SPD increases the rate of descent based on the airspeed, so if you're below the airspeed mark, the descend rate will increase in order to maintain the airspeed (vnav speed) and you're be able to regain the descent path quicker. Even if you use speedbrakes when already on PATH, the aircraft will accelerate to maintain the vnav speed (normal behavior)

 

I only have VNAV offpath issues when flying over turbulence during certain amount of time. The aicraft continues to descending not keeping the vnav path, and i have to adjust with V/S mode until, intercept it again

[Guest happy2]

the shaking is camara efects you can turn all that stuff off in the fmc pmdg options pages

[maniamcool 75]

the shaking is camara efects you can turn all that stuff off in the fmc pmdg options pages

 

Not sure if I wasn't clear in my initial post.. I know how to turn it off but I won't do that. It's kinda cool to have an extra layer of realism.

 

Just wanna know if it the sounds im hearing are normal because it seems over exaggerated.

[Guest happy2]

ah i dont know about the sound myself will have to take their word for it i supose

[scandinavian13 5,192]

Not sure if I wasn't clear in my initial post.. I know how to turn it off but I won't do that. It's kinda cool to have an extra layer of realism.

 

Just wanna know if it the sounds im hearing are normal because it seems over exaggerated.

 

Not sure. Be sure that, if you're using some sort of camera add-on, you disable any effects/sounds it can add in as well.

[chiswick72 145]

Hi Alvin,

 

The shaking functionality and associated pool of sounds will trigger under many conditions, not just on take off and landing.

 

For example. it will trigger in turbulence, overspeed and stall conditions, and the volumes of the sounds will be proportional to the intensity of those conditions.

 

If it was shaking too much due to turbulence then you can always dial down the intensity of the weather to a more acceptable level.