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*Update 15 Mar 22* PFPX Files & Aircraft Model Files for PSX NG FMC Upgrade

Started by G-CIVA, Thu, 26 Jul 2018 12:32

G-CIVA

New updates as of 02 Nov 21....see the original post for further details.
Steve Bell
aka The CC

Ton van Bochove

Thanks Stephen for your continuing job to give us  a touch of the real world!
Ton

G-CIVA

New 'Mega' update as of 04 Nov 21.

See original post for details.
Steve Bell
aka The CC

G-CIVA

New updates as of 01 Feb 22....see the original post for further details...new OFP template available.
Steve Bell
aka The CC

Will

Steve, I have two quick questions for you.

First, I had the pleasure of flying some full long-haul flights in PSX recently. Normally I can't finish a full 15-hour flight but I was able to do this a time or two in the last few weeks, and I noticed that PSX and PFPX were basically in full agreement about the fuel consumption enroute. I'm using the latest version of your 747-400 passenger GE performance file for PFPX, and the agreement was really excellent throughout the whole cruise portion.

However, in each case, the approach (starting at TOD and going until landing) took about 6000 more lbs of fuel than predicted by PFPX. Could be any number of factors here -- weather, primarily, or unpredicted time spent at intermediate altitudes, the speed schedule in the descent, etc. So my question is this: given what you know about PFPX, should I expect that the fuel burn would be as predicted under ideal circumstances? Or are there any known issues with fuel predictions in the final phase of the flight?

My second question has to do with TOPCAT and I understand that you may not have any idea here. But just in case you or someone else does... I note that the N1 predictions for the GE engines are off by a percent or two when compared to the N1 commanded by the FMC. In other words, feeding the PSX weather into TOPCAT, with the same derate, and same runway, calculating N1 for takeoff might give 102.3% in TOPCAT, whereas the FMC commands 104.1%. In this case, should I just assume that TOPCAT isn't perfect and that PSX has the better numbers? Or should I trust TOPCAT in the same way that one would trust the OFP's number for V2 over the FMC value (since the dispatch office has more data to feed into the equation than the FMC does)?

Thanks.
Will /Chicago /USA

G-CIVA

Will,

Will,

With regard to your first Q ... a couple for you to clarify things:

1. When you were conducting your flight planning process did you take into account the extra tack mileage for SID/STAR WPTs added to the RTE?

2. At Release did you copy the WPT Wind data from your PFPX FP & insert it into a PSX 'Wind Corridor' using the PSX Weather Menu Tab?

3. Did you uplink the WPTs WINDS into the RTE in the PSX FMS?

4. Did you fly the planned profile?

TOPCAT - I dont use it.

Best

Steve
Steve Bell
aka The CC

Will

Hi Steve,

1. Yes, the expected STAR waypoints were in the OFP and in the FMC.
2. Yes, I set up a wind corridor. (Hardy: Very powerful feature, by the way, thanks for it.)
3. Yes, winds were uplinked for both cruise and descent.
4. Did I fly the planned profile? Errr...... mostly.

There were three variables that changed, for sure. One was the vertical profile: I couldn't maintain M0.84/340 in a constant descent the whole way from FL390 to the ground without intermediate level-offs. Another was the weather, as the local conditions begin to become more determinative than the wind corridor. And the third variable was the route: there were certainly some deviations from the flight plan as the aircraft got closer to the terminal area.

I'm not complaining about any of this, and I know that operational factors lead to differences from the planned performance. I'm just curious about how PFPX matches in the descent under ideal conditions. Of course I could test this myself with some controlled experiments, but I thought you'd know.

If PFPX matches PSX in the descent and landing to the same degree that PFPX matches PSX in cruise, then I can deduce that the combination of weather and profile alterations simply added 6000 lbs of fuel burn to the trip. This would be good to know.
Will /Chicago /USA

evaamo

Quote from: G-CIVA on Thu,  3 Feb 2022 09:09

TOPCAT - I dont use it.


Out of curiosity, Steve. What are you using for calculating Takeoff/Landing performance?
Thanks!
-E
Enrique Vaamonde

G-CIVA

I have on file copies of old school Paper Take Off Data Cards & quite a lot of legacy FPPM/company specific PERF Charts info for all 3 engine variants

So it's a pencil, paper, chart(s) & calculator effort. As with the landing data calculations.
Steve Bell
aka The CC

simonijs

Quote from: Will on Wed,  2 Feb 2022 16:33
In this case, should I just assume that TOPCAT isn't perfect and that PSX has the better numbers? Or should I trust TOPCAT in the same way that one would trust the OFP's number for V2 over the FMC value (since the dispatch office has more data to feed into the equation than the FMC does)?

Hi Will,

Sorry for this late reply, but I was away from home (and my computers) for several days. About TOPCAT...:

I haven't really looked at N1 percentages but I did look extensively at take-off V-speeds and AutoBrake landing distances as calculated by TOPCAT, while comparing the results to numbers taken from KLM's (obsolete) AOM and/or FCOM.
- TOPCAT V-speeds are usually within 1 or 2 knots from what can be found in the KLM manuals.
- AutoBrake landing distances by TOPCAT, however, are not correct and sometimes off by up to 50 %.

Some examples of this:

Landing in Bogotá (SKBO) RWY 13R, LAW 249779 kg, W/V 040/07, OAT +12C, Flaps 30
AUTO 1   AUTO 2   AUTO 3   AUTO 4   AUTO MAX
2659       2249       1939      1640       1354            TOPCAT
3954       3557       3142      2702       2179            KLM

Landing in Nairobi (HKJK) RWY06, LAW 243694 kg, W/V 080/13, OAT +25C, Flaps 30
AUTO 1   AUTO 2   AUTO 3   AUTO 4   AUTO MAX
3512       2930      2520       2117      1730             TOPCAT
3487       3151      2822       2421      1975             KLM

Landing in Amsterdam (EHAM) RWY27, LAW 251984 kg, W/V 240/18, OAT +11C, Flaps 30
AUTO 1   AUTO 2   AUTO 3   AUTO 4   AUTO MAX
3340       2804      2400       2025      1651             TOPCAT
2669       2491      2328       1998      1676             KLM

Predicted distances by KLM closely match the performance in PSX: if you plan to exit at a certain rapid-exit taxiway and set the autobrake selector accordingly, that is where you will be able to exit.
TOPCAT doesn't recognize FAOR (Johannesburg), you need to enter the former ICAO code (FAJS); nor does it have details for SEQM (Quito), to name just a few.

I trust my numbers over those, as calculated by TOPCAT.

Regards,
Simon (hoping the lay-out remains as I see it in the preview)






Will

Okay, that's good to know. It's too bad that TOPCAT's performance files can't be updated.
Will /Chicago /USA

DougSnow

You know you can download the most current Runway DB from Navigraph correct?

For example I have the Navigraph 2201 Rev 1 Runway DB, and lo and behold, there is FAOR...

Granted, I dont know what EODPs they are using, sometimes they appear as the missed approach and not a true EODP. The only time I enter EODPs is for Worldflight,

evaamo

The thing is, TOPCAT's data for the 744 is derived from/made for the PMDG 747 for FSX. I have no idea which source for landing performance information they used, but I doubt it's close to the actual numbers due to FSX's flawed ground friction. This could explain the differences Simon is talking about.

I wish there were a good alternative to TOPCAT for PSX (both for takeoff and landing), as tables from FCOMs and FPPMs for each engine model are almost impossible to find online, sadly.






Enrique Vaamonde

Hardy Heinlin

The realism of the default autobrake deceleration settings (PSX manual page 486) can be checked pretty easily: Just measure the green airspeed trend vector on the PFD speed tape. Of course, the vector too must work correctly; that can be checked with a clock (how many knot tape marks are passed in ten seconds?). In PSX, the deceleration model and the related indication too are mathematically 100% correct. Minor random variations may appear like in real life due to variable wind or ground friction which the IRS and the brake pressure have to react to like an autopilot does with the flight controls. When the ground friction decreases, the brake pressure should increase, and vice versa -- to maintain the set default deceleration.


Regards,

|-|ardy

G-CIVA

New update as of 01 Feb 22....see the original post for further details.
Steve Bell
aka The CC

Kaido


Mandjare

Hello Steve,

any little chance to have a OASIS HONGKONG 744 template & model file ?

Best wishes,

André

G-CIVA

Hi,

If anybody can supply an original genuine OHK OFP I can probably parse a decent facsimile through PFPX & create a template, but I have no idea what the OFP looks like.

With regards to the fleet ....

B-LFA B747-412 PW4056 Built Jul 1989 Ex SIA 9V-SMC, Ex ABD TF-AMA, Ex LNI PK-LHF - Stored CGK Nov 15

B-LFB B747-412 PW4056 Built Jul 1989 Ex SIA 9V-SME, Ex ABD TF-AMB, Ex LNI PK-LHG - Stored CGK Dec 18

B-LFC B747-481 GE CF6  Built Mar 1999 Ex ANA JA404A, Now with GTI as N263SG (F10C143Y36) Apr 10

B-LFD B747-481 GE CF6  Built Mar 1999 Ex ANA JA405A, Ex GTI N322SG - Stored MZJ Jan 19
Steve Bell
aka The CC

Bluestar

Quote from: G-CIVA on Mon,  1 Aug 2022 00:47
Hi,

With regards to the fleet ....


Steve,

I sent you an email about a week ago, just checking to see if you got it?

Bode
Grace and Peace,

Bode

G-CIVA

Bode,

You should have a reply email & a separate email which links you to the Dropbox files.

Sorry for the delay.
Steve Bell
aka The CC