Hi everyone

I would like to ask about topic title. what are the differences between these two modes? when do they occur? what do they mean? they always show up on the fma ( flight mode annunciator). in addition tell the same about vnav alt, please. I think these 3 modes are only in subject to vnav. when i get this described I will see everything clearly so this very important thing to me which is related to flying 737-800 ngx, without it I am flying but I don't understand what is happening.

 

Pleaseee help me, any answer will be appreciated

Next time one post will be enough to get your answer

 

VNAV PTH means that the aircraft will follow the predicted flight path. VNAV SPD will mean that it'll follow the predicted speed (ignoring the path). Finally VNAV ALT means that the aircraft will remain at the last altitude it climed to in VNAV mode. This one will only occure when the vertical path would want you on another altitude, but you've not changed the MCP altitude. Usually you should be in VNAV PTH mode when in cruise and descend and in VNAV SPD when in climb. VNAV SPD can also become active during descend when your speed varies a lot from the one you're supposed to be at. This can be the case when the winds change during descend and you did not fill in the wind forecast page in the FMC.

sorry about duplicated posts, please someone delete them, this was caused by my internet problem

 

thank u all

 

......but I don't understand "predicted flight path". who predicts it?

could someone answer?

FMC:)

Next time one post will be enough to get your answer

 

VNAV PTH means that the aircraft will follow the predicted flight path. VNAV SPD will mean that it'll follow the predicted speed (ignoring the path). Finally VNAV ALT means that the aircraft will remain at the last altitude it climed to in VNAV mode. This one will only occure when the vertical path would want you on another altitude, but you've not changed the MCP altitude. Usually you should be in VNAV PTH mode when in cruise and descend and in VNAV SPD when in climb. VNAV SPD can also become active during descend when your speed varies a lot from the one you're supposed to be at. This can be the case when the winds change during descend and you did not fill in the wind forecast page in the FMC.

 

and it's possible to decide which VNAV config to use?

Hello Andrew, The 737NGX-800 is a very complex aircraft, in order to get it off the ground the pilot has to know and remember a great deal about the relevant data and workings of the aircraft. Without being disrespectful the wording of your Post conveys to me that you have done very little homework on this subject. I suggest you get hold of some reading matter in relation to Aviation and what the instruments refer to and maybe practice on MSFS default aircraft in the meantime. I am trying to be kind. richard welsh.

ric

Hello Andrew, The 737NGX-800 is a very complex aircraft, in order to get it off the ground the pilot has to know and remember a great deal about the relevant data and workings of the aircraft. Without being disrespectful the wording of your Post conveys to me that you have done very little homework on this subject. I suggest you get hold of some reading matter in relation to Aviation and what the instruments refer to and maybe practice on MSFS default aircraft in the meantime. I am trying to be kind. richard welsh.

 

Richard hello :) your answer is appreciated

I did the tutorial 1 and 2 from pmdg ngx, I know the basiscs but still don't understand everything because i am from Poland and my english is not my native language. i try to learn from operating manuals but as I said before my english is rather intermediate. You from USA or UK are in better situation than me I think. Unfortunately I am not an American :)

 

in addition....... I did also rod machado's ground school

could someone answer?

But Emi just did it above.

Czy przeczytales jego odpowiedz?

There is a Polish forum here on Avsim.

i try to learn from operating manuals but as I said before my english is rather intermediate. You from USA or UK are in better situation than me I think. Unfortunately I am not an American :)

 

 

Andrew,

 

I've been dealing with developers and other flight simulator enthusiasts from other countries for several years, including reading instructions that are not written in my native language, so I appreciate what you have to go through.

 

There are several excellent free translators available on the Internet, and a few pay services that will translate books and manuals (not sure what the cost would be). There are also translators that will translate PDF documents for free, and if nothing else Google Translate will help you translate sections of manuals.

 

By the way, I'm impressed that you were able to get through the Introduction and Tutorials without translating them!

 

Two translators (I'm sure there are many more) that you wish to try are:

 

http://www.translatepdf.com/

 

http://www.onlinedoctranslator.com/

 

 

Hope this helps.

When you program your route in the FMC it will not just create a horizontal path (which heading to fly), but also a vertical path. In VNAV PTH (path) mode the autopilot will keep the plane on that vertical path, even if your speed changes. In VNAV SPD (speed) mode the autopilot will change your vertical speed to keep your airspeed constant, even if that means you don't follow the created vertical path.

You from USA or UK are in better situation than me I think. Unfortunately I am not an American :)

 

Don't worry, neither I am. I'm German so not an native speaker too, but reading through all those forums and also through the OPS manuals of the aircraft is a great training in the english language.

It is a really good training to also try to think in english while flying in your sim. When you do so often enough you will somewhen reach a point where you'll have no more trouble to understand the language, even if you don't get all the words. So don't always try to understand every single word but the meaning of the sentence at all.