Massive problems with cruising altitudes

[arjenfsx 0]

I really like PFPX, but for some reason I can't seem to be able to create flightplans with correct cruising altitudes. Whether I am doing something wrong, I am not sure, but I have tried an awful lot to get it working correctly. In this thread I will show you what problems keep arising when I create my flightplans.

Example #1:

I create a flightplan with the PMDG 777 from FZAA to SBGR. I have my Boeing 777-232LR GE profile selected and matched up with the weights in the actual PMDG aircraft.

I simply enter my departure and arrival airport and my flight number, and let the program auto-select my departure and arrival runway. I set the cruising altitude to OPT with the step climb to 2000 ft, and CI 50.
I select a random payload, and create my route by clicking "Find...". It creates my route and subsequently I select my alternate airport plus its route. Then I click "Compute" and open my OFP. The fuel is automatically calculated. Then I look at my ATC ROUTE and this is what I got:

N0445F240 BZ3A BZ B732 IT/N0483F380 UW118 LIKAD UT357 TETUX DCT

10S000E/N0480F400 14S010W 18S020W 20S030W/N0473F430 DCT EKALO UL340

LOBIK DCT ADA UW50 NILSA NILSA6

So for the first leg of the flight, it wants me to stay at only FL240, then climb to FL380, then FL400, and then FL430?! A 777 isn't able to climb that high, definitely not with these weights.


Example #2

Obviously I don't want to be at FL240 for the first leg of the flight, I want to climb to the optimum cruising altitude, so I re-plan the route by using the "Find..." -> "Upper Airspace"-option to make the program selecft upper airways only, and this is what I got.

N0484F380 XIVM1A XIVMA UA611 VNA UL340 ONTAR/N0460F280 UL340

ILGER/N0480F400 DCT 18S020W/N0474F430 20S030W DCT EKALO UL340 LOBIK

DCT ADA UW50 NILSA NILSA6

So it wants me to climb to FL380 for the first leg of the flight. That is not even possible because the aircraft is still to heavy at this stage to go this high. Later, it wants me to decent to FL280, then climb to FL400, then FL430 (which is too high). I am getting extremely confused here now...


Example #3

So I decided to try something similar with the 737-800WL. Again, same procedures here, the profiles match up with the NGX.

The flight is going from EHRD to LFBE, and this is what I get:

N0449F370 WODY1B WOODY UN872 MEDIL UQ237 LMG UN10 VELIN UN857 SAU DCT

At first, seems like a pretty good route, right? Well, when I actually fly this route, the optimum initial cruising altitude is FL390 and you can even step to FL410 for the most optimal fuel burn. However, even though I selected OPT in the Cruising Altitude field, it is giving me a cruising altitude lower than FL390, and doesn't even let me step to a higher altitude despite the fact I set "Last step" to 100 nm.

On a side note, PFPX has not even selected a proper STAR-connecting waypoint in this case, even though LFBE does have STARs and transitions.


I have tried a few flightplans that go through the USA, and everything was 99% fine. My cruising altitudes might have been a bit too low for what is optimal in those cases, but at least I am not getting any strange descents and climbs in the middle of my cruise leg. So by the looks of it, PFPX ceases to deal properly with non-North American airways, and this is a serious issue for me.

If I am doing something wrong, and I assume not, I'd like to know what.

Thanks in advance.

[dougsnow 50]

Have you checked the maximum allowable altitude along the airways? Europe gets insane with the min and max altitudes along the airways there.

[3TMaverick 1]

It's a navigraph database error. UL340 is a high alt with an MEA of 25,000 but in PFPX it shows Min/Max of 250/280 respectively. Before you compute you will need to review the DETAILS tab of your route to check your airways and if you find errors then you can use the AVOID checkbox in the Advanced Route Finder to avoid airways, etc.

[Ruhrpilot07 15]

Have you checked the maximum allowable altitude along the airways? Europe gets insane with the min and max altitudes along the airways there.

Hum. I have never heard of MAXimum altitudes, concerning IFR (Juliett) airways.

It depends on your destination. I know SBGR Guarulhos fsx airport from 2012, when I tried to land there during the F1 race. But due to weather, or Copacabana reasons...

I got stuck at Galeao (SBGL).

The flight from FZAA is approx 3751 nautical miles, so, if that would be a flight for me and my pmdg B747-400X, I'd request high alt, i.e. FL350 or much higher.

[arjenfsx 0]

Thank you guys, I will try and follow your tips and see what happens.


Nevertheless I think PFPX should include an option for a minimum cruising altitude, so it will avoid certain airways that create these troubles.