T7 fuel planner

[Richard McDonald Woods 168]

For those of us who love to get as close as possible to the real world, PFPX will be THE tool to give exactly real world accurate OFPs. That's the decared aim of PFPX, and my main interest in flying PMDG aircraft.

 

So I shall then be able to match my actual flight to the planned flight. This and radio work is what keeps the real crews busy on long sectors. I expect the PMDG777 actuals to meet the PFPX plans to a great extent. Where there are discrepancies, it will be interesting to determine where the errors lie.

 

I know it will be fun, and keep me busy. If it's not your idea of fun, then so be it.

 

Cheers, Richard

[Airbusman330 300]

I usually have a friend who dispatches my flights (I really, really, really hate flight planning) so they may enjoy this program a lot. 

[Heffron 29]

Yes -- so can't I.

 

I only hope that the aircraft's performance data used by PFPX for the calculations fits the peformance data PMDG (and others) uses for their simulation... anyone? Ryan?

 

What I've read is that both PMDG and PFPX used data from Boeing itself. So they should be quite the same?

[Richard McDonald Woods 168]

I do hope so ^_^

[Heffron 29]

scandinavian13, on 18 Jul 2013 - 05:40 AM, said:

 

Realism in the sense of...?

 

You're right that fuel calculation is a crucial part of any flight operation (not just commercial.) The FMC is going to be the most accurate tool out there, so why waste time (and spend money on) tools that aren't as accurate?

 

Sure, it's somewhat neat when numbers work out closely, but there's nothing truly more realistic about using a separate program. In reality, the dispatcher is using the same code as is written into the FMC anyway...

Realism in the sense of how it's done in the real world. It might be that the dispatcher does use the same code as in the FMC but he is not sitting there in the cockpit just put in some fuel, look in the FMC if it is sufficient and if not he adds some more. He is calculating fuel through a separate program in the dispatch office, isn't he.

 

And how do you know PFPX won't be as accurate? It uses Boeing data.

[tcas_climb 45]

I have to agree with, Mr Swinkels here, i like the realism of planning a flight properly and keeping track of the fuel burn as you go along, I have to say that i sometimes enjoy the planning stages more than the actual flying especially when its a long haul flight, checking notams, enroute alternate weather etc. and things do get even more interesting when takeoff weight and field length becomes an issue, you have to tinker with the fuel a bit, or even think about the option of doing Re-dispatch planning which is one of the features im most anxious to check out in PFPX, or simply kick some bags and pax out the door. And since PFPX uses real world aircraft data, when combined with the 777 i expect to see numbers which are pretty acceptably close.

[thepilot 581]

Realism in the sense of...?

Realism in the sense of how it's done in the real world.

Indeed! I see it's possible to do it with the FMC, but I imagine you'd have to fiddle around with it quite a bit. I.e. start with an estimate, see what your trip fuel is, calculate the contigency, then see how much you need to get to your alternate (if the CDU is even capable of showing that), and throw in some taxi fuel, final reserve, and possibly some additional fuel at the Captain's discretion. Not really how it's done in the real world...

Also, keep in mind the FMC will adjust its fuel and time figures as the flight progresses. Printed numbers on a nav log obviously do not. That way, you can spot any possible discrepancies along the flight and analyze their cause... it might just be a stronger headwind than anticipated... or a fuel leak. :ph34r: Interesting times ahead for sure.

What I've read is that both PMDG and PFPX used data from Boeing itself. So they should be quite the same?

I took it that since PMDG has close relationship with Boeing ("officially licensed product"), they have access to privileged amplified data that isn't available to the general public. I am not completely sure if that is the case with PFPX as well.

[Richard McDonald Woods 168]

Marius,

 

Doug Snow, a professional dispatcher, and Christian Grill have been going to extreme lengths to ensure that they only use officially published data for PFPX. This is probably why they have been constantly criticised for not publishing the base data for additional aircraft.

 

I feel that, after years of making-do with software that wouldn't be tolerated in the real world, we are now getting quite close to reality. Perhaps it will take some extended period of use with these new products to forget our less-than-real pasts. It will be shown by fewer people saying that PFPX does not accurately support the PMDGxxx, rather than saying that PFPX and/or PMDGxxx may not accurately mirror the real world.

 

Cheers, Richard

[scandinavian13 5,192]

Realism in the sense of how it's done in the real world. It might be that the dispatcher does use the same code as in the FMC but he is not sitting there in the cockpit just put in some fuel, look in the FMC if it is sufficient and if not he adds some more. He is calculating fuel through a separate program in the dispatch office, isn't he.

 

And how do you know PFPX won't be as accurate? It uses Boeing data.

 

First, I suggest you go back through my posts to see where i mentioned PFPX anywhere.  To save you the reading, nowhere did I mention PFPX, and more specifically, nowhere did I cast doubts on its accuracy.

 

What I did say, however, was that by and large these planners are nowhere near as accurate as what the FMC will give you.  Heck, even TOPCAT will get you close enough, but close enough may not cut it on a flight with high winds, with a giant ground delay in EWR, and so on.

 

...and yes, the dispatcher may well be sitting at a terminal somewhere other than the aircraft, but the issue remains: he or she is calculating with the tool that will give them the highest confidence in the resulting number.  If you're using any tool currently out in the sim realm, you are not.  Even if it feels more realistic, you're getting a less accurate number.

 

Yes, this is Flight Sim, and the extra fuel doesn't cost money.  I get that.  What I'm trying to pick at is this idea that you have to use external programs to be more realistic.  Sure, the process feels more realistic, but you're sacrificing your data integrity in the process.

 

It's like those kids who put giant wings on Honda Civics:

Yes, it certainly makes them think they look so much cooler.

The reality, however, is that they just reduced their power both by adding downforce to the rear of a front wheel drive car, and by adding a ton of drag.

 

...but man it certainly looks fast!!!

 

Indeed! I see it's possible to do it with the FMC, but I imagine you'd have to fiddle around with it quite a bit. I.e. start with an estimate, see what your trip fuel is, calculate the contigency, then see how much you need to get to your alternate (if the CDU is even capable of showing that), and throw in some taxi fuel, final reserve, and possibly some additional fuel at the Captain's discretion. Not really how it's done in the real world...

Also, keep in mind the FMC will adjust its fuel and time figures as the flight progresses. Printed numbers on a nav log obviously do not. That way, you can spot any possible discrepancies along the flight and analyze their cause... it might just be a stronger headwind than anticipated... or a fuel leak. :ph34r: Interesting times ahead for sure.

 

I took it that since PMDG has close relationship with Boeing ("officially licensed product"), they have access to privileged amplified data that isn't available to the general public. I am not completely sure if that is the case with PFPX as well.

 

I'm guessing you haven't looked at tutorial 2...

It's really not that difficult, and you're doing just about as much work as you would be with some external program.

 

I really wouldn't drag the "that's not how it's done in the real world" into this discussion because neither side is how it's done in the real world.  In the real world you wouldn't be dispatching yourself through a program or banging on the FMC to give you a number.  Note that I just discredited my own argument there, too.

 

My argument is not that it is more realistic to use the FMC; rather, it's more accurate.  In fact, nowhere did I state that it was at all more realistic, simply because neither are particularly real avenues to get you your numbers.  

 

I do know that one method is currently more accurate, however, and I'm not going to go tossing out accuracy for a mere feeling of realism.

[Heffron 29]

First, I suggest you go back through my posts to see where i mentioned PFPX anywhere. To save you the reading, nowhere did I mention PFPX, and more specifically, nowhere did I cast doubts on its accuracy.

 

What I did say, however, was that by and large these planners are nowhere near as accurate as what the FMC will give you. Heck, even TOPCAT will get you close enough, but close enough may not cut it on a flight with high winds, with a giant ground delay in EWR, and so on.

 

...and yes, the dispatcher may well be sitting at a terminal somewhere other than the aircraft, but the issue remains: he or she is calculating with the tool that will give them the highest confidence in the resulting number. If you're using any tool currently out in the sim realm, you are not. Even if it feels more realistic, you're getting a less accurate number.

 

Yes, this is Flight Sim, and the extra fuel doesn't cost money. I get that. What I'm trying to pick at is this idea that you have to use external programs to be more realistic. Sure, the process feels more realistic, but you're sacrificing your data integrity in the process.

 

It's like those kids who put giant wings on Honda Civics:

Yes, it certainly makes them think they look so much cooler.

The reality, however, is that they just reduced their power both by adding downforce to the rear of a front wheel drive car, and by adding a ton of drag.

 

...but man it certainly looks fast!!!

 

I am not a fan of Honda Civics with huge spoilers and I think it makes them look dumber than faster.

Of course the FMC will be the most accurate device when it comes to fuel calculations, especially when fed with wind data during flight. However if you don't like to sacrifice accuracy for more realism in terms of flight planning, that's entirely your choice. It might be that PFPX is less accurate, after all it's an estimation of required fuel but enroute conditions like winds and temperatures are taken into account so i reckon it will be accurate enough, for me at least. Realworld flightplans aren't 100% accurate as well, are they? Otherwise those gaps for actual FOB and/or fuel burn-off wouldn't have been necessary. On the other hand PFPX is so much more than fuel planning. It's about the whole package. Routing, ETOPS, Re-Dispatch Planning, NOTAMs and so on. You can do this without PFPX but PFPX just puts it in a nice package, looking like realworld OFPs and i know lots of virtual pilots who like it this way, who like to have those papers in the cockpit just like me.

 

I don't necessarily think external programs are more accurate, my point is that dispatcher for instance use Lido, which is not the FMC. Dispatchers use external programs, not the FMC in the cockpit itself. And again, realworld OFPs are also not 100% accurate. Most probably more accurate than PFPX but that margin is understandable for flightsim software. But PFPX might give me outside the PMDG FMC itself, the highest confidence in the resulting number.

 

Just the way I see it.

[scandinavian13 5,192]

 

 

On the other hand PFPX is so much more than fuel planning. It's about the whole package. Routing, ETOPS, Re-Dispatch Planning, NOTAMs and so on. You can do this without PFPX but PFPX just puts it in a nice package, looking like realworld OFPs and i know lots of virtual pilots who like it this way, who like to have those papers in the cockpit just like me.

 

Again, nowhere in my posts did I mention or bring up the accuracy, or validity of PFPX...ever.

 

Why?  Because the topic at hand is simply fuel planners (despite the allusion to PFPX by the OP).  I'm simply providing an argument on the base level that you're not going to get any more accurate than the data from the FMC itself.  That's it.

 

 

 

I don't necessarily think external programs are more accurate, my point is that dispatcher for instance use Lido, which is not the FMC. Dispatchers use external programs, not the FMC in the cockpit itself. And again, realworld OFPs are also not 100% accurate.

 

While Lido is not the FMC, it uses the FMC calculations as a base and then applies a correction factor through learning technologies.  They basically took the manufacturer's process and made it better.  They didn't just take basic numbers of climb burn is this, cruise burn is this, descent burn is this (plus adjustments for wind, weight, temp and altitude - like you see on most charts of processed data).  Rather, they are using the same algorithms the FMC uses, and are adjusting those calculations with correction factors.  These correction factors come from using the program and evaluating its accuracy.

 

...and you're right.  Nothing is going to be 100% accurate, ever.  The issue of life is that it isn't black and white, but for some reason people still try and force it to be.  It doesn't matter if nothing is 100%.  If something is closer to 100% than something else, then it's still the safer bet.

 

 

 

Again, all I'm trying to do here is dispel the idea that it is more realistic to get your numbers from an external planner.  That's it.  Nothing more.

I'm not trying to tell people they have to do it my way.

I'm not telling people that PFPX isn't worth it.

I'm not telling people that not using the FMC means they're going to run their tanks dry.

 

Feelings of realism don't always mean more realistic, especially when most of the people asserting realism have never been involved with airplanes to the level where they'd actually have an accurate basis for the assertion.

[LRW 42]

 

 

I am going to have to restock on paper

Isn't there an airline joke about a tree dying for every long haul flight plan?

 

I'm looking forward to using PFPX for long haul planning and recording actuals against planned as I've seen them do in the JustPlanes T7 videos.  Rather the print it all out, though, I could annotate the PDF's with the actuals and not waste the paper or toner.  Although I'll probably print it all out the first time and do it by hand, anyway.

[thepilot 581]

 

 

In the real world you wouldn't be dispatching yourself through a program or banging on the FMC to give you a number.

 

I possess quite a few videos from the justplanes Air Canada series and I can tell you each one of them starts in the crew room rather than on the aircraft itself. Reason being simply that they "essentially self-brief" as one Captain put it. That means they go through the whole OFP, including fuel planning, weather forecasts and even aircraft performance figures before they jump on board. I would like to recreate that using PFPX as it gives me a feeling of doing it like in real-world aviation, and I am definitely better prepared for the flight.

 

 

 

My argument is not that it is more realistic to use the FMC; rather, it's more accurate.

 

If the performance data PFPX uses for its calculation matches the performance data PMDG uses for their simulation (which is apparently the case, see above) - the accuracy level is simply the same. However, there is one big advantage: you have two independent calculations that you can check against each other. If the numbers don't add up, you know something is off, and you can start to investigate. It will be great to have a nav log at hand and see how the calculations compare to the actual figures along the route, when passing waypoints, VORs etc..

[Jeff_B 8]

What is the average fule burn per hour in kg's on the T7?

[CaptCraig 226]

 

 

For those of us who love to get as close as possible to the real world, PFPX will be THE tool to give exactly real world accurate OFPs

 

You should check out vacanada.org virtual airline.  they produce OFPs that are identical (up to 95%) to the real ACA printouts from their Lido software.