BW901

Matching Takeoff Weight is the bit that matters. The total weight of the aircraft is what drives the performance and fuel burn, irrespective of how that total weight is made up. You add bias through the Aircraft Editor. Select the relevant aircraft in the Aircraft Database and then select Edit. Type the bias into the relevant data entry box, make sure you save when you have changed the appropriate value. APM has nothing to do with what we're proposing here, simply type in the suggested values. If you are finding that the TOW in your sim and in PFPX aren't matching then my suggestion is remove any bias. Do a flight with matching weight, see what percentage the burn in climb and cruise differs and type that into the Aircraft Editor. Keep things simple. One other thing just to be sure nothing external is messing with your PFPX setup - did you use a template to create the aircraft? Using a Template to create an aircraft rather than creating straight from the performance file can sometime cause problems, personally I never use them, and I don't provide templates, only the .per files.

Ray, I've never used drag bias - that may then also affect speeds. It is very hard to understand what's happening without seeing the whole picture. Fuel burn is only one element in the whole equation. The ideal would be if we had the OFP used as it is in the real world, as a How-gozit. With actual time and fuel, and some IAS/TAS/wind checks annotated onto a printed OFP it would be much easier to see exactly what's going on. However I appreciate that's something that only a few simmers would ever do. Sorry if I'm repeating what Stephen has already asked and for doing the IT equivalent of "is it plugged in" but - 1. Does your PFPX weather match whats in the sim? 2. Does your takeoff weight match between PFPX and the sim - forget all the underlying fuel, weight, ZFW, etc, it's the TOW which is going to drive things. I just ran a 2 hour sector at a few different weights and the % increase in TOW results in a similar % increase in fuel burn. 3. PFPX and sim aircraft types match (winglet/non-winglet) Otherwise based on your typical flight examples bump up the PFPX Climb fuel bias to around 10%, increase the cruise bias slightly, to maybe 7-8%, add an extra couple of hundred pounds for ATC getting you down low early on the approach and you should be there. Jon

Ray, If you remove that bias, PFPX's calculated fuel is going to reduce - by 5.6% or typically somewhere around 100kg for the climb segment. That is only going to increase the differential between PFPX's burn and your sim burn. At the moment given the way your sim is behaving you'd be wanting to increase the climb bias to somewhere around 10%. Something is not right, because your sim burn is high in all three flight phases, even in the descent you're burning 200 (units on the bar chart?) more than PFPX's calculation. I no longer have P3D installed, I now only use X-Plane, so I can't take a look I'm afraid. Jon

At higher weights a 738 is going to consume somewhere between 1700 and 2000kg getting up to typical altitudes (and I've just been looking at a bunch of realworld OFPs to verify that). That matches the numbers in the performance file. You appear to have already added 5.6% fuel bias on the climb. If you are saying that you're burning a few hundred lbs more than that in the sim.... I'd say CI 45 or 35 is high for normal planning purposes, but I'm open to correction. Every OFP I've been looking at is between 10 and 20. Having said that Climb at CI40 vs CI10 only adds about 3% to climb fuel burn.

Forgive me if I've misread the numbers but for EBBR-EDDM it seems that PFPX calculated a trip burn of 5400lbs, vs PMDG's actual burn of 5500lbs (read to the nearest 100 lbs?). That's a 100lb (45kg) difference, or about 1.8%. To quote - "GIven the cost of PFPX and the PMDG737 it's disappointing the calculations / usage aren't more accurate" Seriously ??!! What's causing the bigger variance in point numbers is a 200 lb higher start/taxi burn before departure. Irrespective of how PMDG or FSX/P3D models burn on the ground or at low thrust BRU is a big airport, it would be normal practice to apply a higher fixed taxi fuel allowance at larger/busier airports. As for the FSX/P3D fuel burn vs temperature issue, I did post a good while ago asking for folks wanting to help with testing revised files. I had one reply for 1 aircraft type, and didn't get any feedback on the revised performance file. It would seem that 99.9% of users aren't that bothered, which seems to be borne out by how the majority of Twitch streamers use/apply both flight planning applications. Cheers Jon

Stephen, no worries, thanks for your continuing support

Hi Stephen, to avoid 'busflyer some confusion, the file on Airlinerperformance is for the Fokker 50, not the DA50 (Dassault Falcon 50)! I have produced files for the Falcon jets, but not publicly released any of them. Cheers Jon

Hi DLRK. It shouldn't. Unfortunately with no details it's impossible to try and recreate any issue.Perhaps a copy of the OFP so we can take a look might help?

Folks, to clear up any confusion PFPX DOES support CI for Climb and Descent, provided the aircraft profile used includes the appropriate CI data. If you are using a supported aircraft type enter your cruise CI and select ECON in the Climb and Descent windows and the sector will be planned at the defined CI for all three flight phases.

Gents, from the above and some private conversations it's great to see some feedback on using the files, I think we can incorporate some changes. On that note if there are any P3D users who fly PMDG and the QW787 and would like to help test some revised files drop me a PM please.

100% agree, perfect summary. "Jack of all trades, Master of none" is what happens to software which tries to do everything. The support of 3rd party aircraft is one area where the developer of flight planning software for the sim world faces a burden not present in the real world (a single standard sim-wide FMC data format would be great lads....) - revenue generating ability is the other, I'm constantly amazed by what some simmers expect; if only they knew what real world airlines actually pay for our flight planning capabilities. I'll keep helping with data as new flightsim aircraft are released, if I felt PFPX didn't have a healthy future I'd do other things with my life.

Apologies folks. As I was running numbers for the DC-10-10 I saw the DC-10-30 hold fuel flows were incorrect (the 10 has only 3 engines, not 4 . Correct file v1.10 now uploaded.

Hehe! New DC-10-30 and updated 747-400ER now uploaded. If anybody with the Aerosoft DC8 can please post the appropriate weights for the aircraft I'll finish off that profile.

Hi Phil, I've done 90% of the work on a DC8-50 profile, and if I can have all the weights for the Aerosoft model I can finish it. And I have completed a new DC10-30 profile, just haven't published it yet. Cheers Jon

Hi Philippe, hope you're keeping well. You reminded me I have some more 400ER data now so I'll expand that profile shortly. Cheers Jon