Who uses VNAV to descend .... and who doesn't?

[Guest Erups]

I think you may be just banging your head on a not su publicized bug, i hope they fix soon.There is a bug in the vertical management of the AFDS that mainly affects flight in case of multiple contraints.In pratice, after some operations perfomed, the AFDS gets stuck in a shallow dive, and you end up with your vnav path going to hell.this has been confirmed by PMDG, but still not fixed.In this case the only available solution is to recycle vnav.Another problem may be an incorrect flight management from the pilot.In an italian ML, i had a discussion with persons believing PMDG 737 dynamics were not that good as other said.I confirmed with data that they were essentially wrong:what they were saying was tthe same you're saying, vnav is unreliable, you can't descend at a decent speed, etc etc etcUsual fuss.Now i did a very stupid flight, in a fully loaded 800, and demonstrated that it did everything on its own, without my intervention unless for the speedbrakes when it came the time to slow down from 315 to 240kias.So now what i am saying is that a RL plane is a very complex machine, full of physical limits, and crews are throughly trained to operate such a machine in a complex environment.Reproducing such a complex machine, means the user has to replicate at least some of the actions the real crew would take.So in simple words, this is not an SF260, or a c172.It's a Boeing (and that should be just enough) 737 NG.It has its demands, and you should comply.

[Guest Paragon]

I suffer from this bug also, it gets' stuck at a descent rate of 500 ft/min or so. What's the latest news from PMDG on this bug?

[Guest Erups]

>I suffer from this bug also, it gets' stuck at a descent rate>of 500 ft/min or so. What's the latest news from PMDG on this>bug?There is none.I only succeded in haveing a "we'll fix it but right now we are deep in the QOS development cycle".I asked to at least publish this in the so appreciated "Maintenance Status Board"...Not only did this not happen so far, but right now the MSB is even offline (i hope for update).

[Mats_J]

Mikkel - There's an easy work-around. Recycle VNAV. So no need to suffer. And it keeps you awake during VANV DES. ;-)Hope it helps

[Guest Erups]

Complitely OT in this thread:Mike you're really a beta geek :DBet you're also an MS betatester? :-p

[Mats_J]

Claudio,"Are you talking to me? To me!" :+If so...First. My name is Mats. Like in floor mats. :-coolNah I'm not as much beta geek as Randy! :-lolI am not a beta tester for MS. I wouldn't want to I think. For MS I think quantity goes before quality so would be a little unrewarding. I only team up with "the best of the best of the best". Actually these are the only two beta assignments I've ever had:-)Hope it helps, hahaha

[Guest Erups]

>If so...>First. My name is Mats. Like in floor mats. :-cool>Secondly. Nah I'm not as much beta geek as Randy! :-lol>>Hope it helps, hahahaSorry!Don't know why, my fingers digited Mike instead of Mats :-halo

[Guest REDBEARD]

According to TUI belgium Airlines for both NG and 400,they always use vnav as it is the best for less fuel consumption.Virgin Express pilot do use VNAV as well.A captain also told me that pilots who use FLCH are not aware of their system or are not very confident with it.Anyway,the FMC is done for something,it is not a unuseful tool.olivier sinnaeve,airport security EBBR

[Guest ba747heavy]

>I fly the majority of my flights online with VATSIM and>usually let VNAV handle the initial descent to the first or>second published altitude restriction.Thats how I do it too. Usually once I hit 10k, and slow to 250 I switch ot LVL CHG and go on with my life. This seems to work for every published procedure I have used when flying on VATSIM.

[Guest Zapper]

Hi Gents,Interesting thread we have here :)I know I shamelessly promote the use of VNAV and that is for one reason only. It is how it is done out on the line. The difference I need to point out is that the Forecast winds available online may be inaccurate, if you have a latency issue with the net then you may get a 30kt wind change in a fraction of a second or your PC may just not me able to supply the CPU and memory grunt needed to ensure smooth AFDS operation. {I am not a PC guru but understand that the AP needs some kick to make the sim fly smoothly.. ie Altitude Capture etc}As suggested in various tutorials, VNAV PTH is by far and away the most efficient and economical - and that is what a Commercial Pilot is paid for - to operate safely and efficiently in a way that maximises the Company's profit.When VNAV lets you down, for whatever reason... and it does happen IRL too for a plethora of variables in any given flight, then your job as a Pilot is to make best use of the available systems to achieve optimum flight path management.. this may be a recovery technique such as LVL CHG or VNAV SPD or even handflying but whatever you do make sure you are getting the best from your ship.. that is why they have us up the front and not just another old x86 :DAll The Best Guys and I am very glad to see people really thinking about this topic.Rgds,

[Guest Kultsound]

>According to TUI belgium Airlines for both NG and 400,they>always use vnav as it is the best for less fuel>consumption.Virgin Express pilot do use VNAV as well.>A captain also told me that pilots who use FLCH are not aware>of their system or are not very confident with it.>Anyway,the FMC is done for something,it is not a unuseful>tool.Well, as far as I understand it all depends on airline. Every airline has their own sets of rules and policies for their pilots to adhere to. VNAV makes not much sense when arriving at, say, Heathrow where things change quickly and you will most probably end up in a hold. The opposite would be trans-atlantic crossings where VNAV makes all the sense in the world. Btw, let's not forget in the midst of this discussion that there are still loads of planes out there without VNAV and mysteriously they manage perfect descends.. :)// Peter A. Mankowskihttp://www.mankowski.co.ukhttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

[crvm]

>According to TUI belgium Airlines for both NG and 400,they>always use vnav as it is the best for less fuel>consumption.Virgin Express pilot do use VNAV as well.>A captain also told me that pilots who use FLCH are not aware>of their system or are not very confident with it.>Anyway,the FMC is done for something,it is not a unuseful>tool.>>olivier sinnaeve,airport security EBBR Funny the 737 does not have a FLCH MODE ;D so much for his opinion eh?Best Wishes,[h4]Randy J. Smith[/h4]http://www.rawbw.com/~bdoolin/shinault/Animation1.gifCaution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | NEC LCD 1980SXi 19" | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro |

[Guest Kultsound]

> that is why they have us up>the front and not just another old x86 :DFunny you should say that. Actually, the Motorola 68000 and even it's relative from the old good days, the 6800 used to be the number one competitor againts Intel in the old days of the x86. Modern derivatives of the 6800 and 68000 still power many electronic subsystems and surely one or two can be found in a modern airplane... so... theoretically they actually have an old x86 in front of them! :-lol // Peter A. Mankowskihttp://www.mankowski.co.ukhttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

[Guest Erups]

> Funny the 737 does not have a FLCH MODE ;D so much for his>opinion eh?Hem...What's the difference betweenFlight Level CHangeLeVeL CHanGe?

[crvm]

The difference is FLCH is found on birds like the 767 and LVL CH is found on the 737. A 737 pilot never calls LVL CH FLCH CH since in fact it's not on the 737. As for the technical differences I am not sure but that is not my point now is it ;DBest Wishes,[h4]Randy J. Smith[/h4]http://www.rawbw.com/~bdoolin/shinault/Animation1.gifCaution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | NEC LCD 1980SXi 19" | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro |