Strange crusing altitudes from PFPX

[ArjenVdv 190]

I have another question about PFPX regarding the NGX and the average wind component. PFPX always uses the HD/TL[wind speed] format, but the NGX asks for [speed]/[direction]. In the PMDG MD-11 you're left with a similar problem, but vice versa. For take-off, you need to convert [speed]/[direction] to HD/TL[wind speed] format. But this is not a problem: you just draw an imaginary triangle and use some maths (sin/cos/tan) to figure out your headwind component. In case of the NGX, there is litterally no way of using this method to convert HD/TL[wind speed] to [wind speed]/[direction] simply because you need to know either the actual average wind speed, or the actual average wind direction, and as you don't know any of those, there is no way to figure out what to enter into the CRZ WIND field. An option is of course to enter all the winds for all the waypoints, but that takes way too long for me. Does anybody know a way of figuring out the average wind and direction from a wind component?


Secondly, I have got something to update about the initial cruising altitude problem with PFPX. I haven't found a solution to stop the program from doing this, but I have found a way of easily modying the route to bypass these problems. Here's what you gotta do:

1. Leave your cruising altitude on OPT and create your route by clicking the "Find" button found on the upper toolbar, then click "Upper Airspace", now PFPX will choose the highest altitudes it can use.
2. Under the route tab you use when normally creating your route, there is a dropdown menu that should currently be set to "(Auto)". Click it and choose "Edit..."
3. In the window that now comes up, you can see two tabs: a Route tab, and a Details tab. If you go to the details tab, you can see all the waypoints and airways of your route, and on the right you can see two columns that display the minimum and maximum altitude of an airway. If the route has an airway with a maximum allowable altitude that is below your desired cruising altitude, then this is the culprit of the problem.
4. To get around it, click the "Find..." button on the upper toolbar of the window you are currently viewing. Click it and then click "Advanced...". In the window that has come up, you should see an "Avoid airways, etc." option. Check this option and in the box right under it, enter the name of the airway that you want to avoid. So in my case with my FZAA - SBGR flightplan, I enter UL340. After this, just click "Find..." and then click "Apply".

The route should now consist of slightly different airways or waypoints without any cruising altitude problems. This is all you can do for now.

[g_precentralis 191]

You can simply summarize wind speeds at every waypoint and divide by number of waypoints. The same for direction and temperature.

 

You can calculate wind direction and speed only from both components, or if you know TAS, GS, HDG and TRK (but you cannot find average wind).

[scandinavian13 5,192]

I liken the route commentary to getting an expensive add on and expecting it to do everything for you, while saving your [rear] if you mess up.  It's not going to happen.  There's a reason there's still a person up front - it's still better than a computer at decision making a good portion of the time, and it's still better in non-standard situations most, if not all of the time.

 

Likewise, there's a reason the dispatch position exists, is staffed by a person, and is (in the 121 environment) normally not the pilot - it's a lot of work, and a computer can't do it very well.  If you're thinking PFPX is going to just automatically look at every single restriction out there and just dump out some route, it will, but it's not going to be a good one.

 

Trash in - trash out.

 

As mentioned earlier, in cases with varying max alts, the lowest max alt will be set as the cruise altitude for the flight.  Simple.

All of these suggestions as "workarounds" are really just sidestepping the real issue.  There's a constraint.  How you handle that constraint is up to you, and how efficient that handling is determines your edge (or losing your edge) to the competition who handles that constraint differently.

 

While the above makes it seem like I'm pushing real world emulation on people, I'm really just trying to illustrate the point that - just like in flying - there's often vast grey areas.  Whether you like it or not, PFPX is a dispatch software, and a dispatcher's job is to work in a lot of that greyviation.

• Should the lowest max alt be used as a cruising altitude?
• Should a different route be used?
• What cost index is best for a route like this?

Is there a verifiable right answer for that?  No.

 

If you're expecting a computer to cough up a perfect flight plan with little to no valuable input, you're going to be sorely disappointed no matter where you go.

[g_precentralis 191]

Imo, it's unacceptable for dispatch software to build you roller coaster route (we go up we go down... weeeeeee). It should at least inform you why it built such a route, with list of constraints took into account (it doesn't really help when I have to open AIP of every country I'm flying above). Or simply to show you a message "I cannot find a reasonable route, do it yourself".

[voske 34]

I have another question about PFPX regarding the NGX and the average wind component. PFPX always uses the HD/TL[wind speed] format, but the NGX asks for [speed]/[direction].

IIRC (not near my computer right now) there are also OFPs available that provide average wind direction and average wind speed.

[ctstech25 5]

I use ActiveSky 2012 or now AS Next for wind components.  After importing my flight plan from PFPX into ActiveSky, it gives me the average wind components.  I fly almost exclusively in US and get PFPX behaving nicely most times. I have had PFPX send me up and then down, but only a couple of thousand feet diff. , and I was wondering if the predicted winds aloft factored into the PFPX plan.  However, I am way too lazy to actually go do the research on that question, so ignore any descents in the PFPX plan.  Since gas for sim is free, I don't worry too much... :lol:

[hopskip 253]

I have been flying the Emirates flight from Dubai to Tokyo Haneda a few times and PFPX puts you on a very southerly route compared to the real one.

 

I have been creating my own flight route based on the FlightAware track (You can't see the route in text form, but you can see where the green track (where the real plane went) is).

 

After spending several minutes (maybe 30+ minutes) Building my route, I let it build the route and then use the fuel plan it gives me.

 

I'm arriving in Japan within 0.5 tonnes of fuel of the predicted fuel burn all the time.

Even if you make your own route, the fuel plan will be very very accurate, assuming the weather injection is correct and you departed roughly at the same time you told PFPX you would be departing (and obviously if you are carrying the same weight and using the same Cost Index or Cruise selection you set in PFPX ie: no planning LRC mode and then flying for 9 hours in Cost Index 85 at a different flight level).

[scandinavian13 5,192]

Imo, it's unacceptable for dispatch software to build you roller coaster route (we go up we go down... weeeeeee). It should at least inform you why it built such a route, with list of constraints took into account (it doesn't really help when I have to open AIP of every country I'm flying above). Or simply to show you a message "I cannot find a reasonable route, do it yourself".

 

...then go tell them.

 

I don't see a problem with it.  If you give it the flexibility, then there's no problem with it in my eyes.  If you don't want that as a result, re-run the flight build with more restrictions (like the aforementioned max alt at the lowest restriction).