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Michele Benedetti

PFPX Concorde Profiles - Fuel Planning Issue

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Ray Proudfoot
11 hours ago, Fraser Gale said:

I wouldn't put money on the subsonic fuel being wrong for a full supersonic flight with CPS.  It is very complicated stuff, and I'm not going to get into it but that isn't really how the Concorde fuel plans work - for real anyway.  Things are calculated in segments: take-off; climb to subsonic cruise; subsonic cruise; climb to FL430/M1.7; supersonic cruise; descent to destination.

On a supersonic flight, the percentage of fuel for subsonic calculation is small compared to climb and cruise hence has less effect on total fuel, whereas pure subsonic operation messes up the segments.  Plus, to do it properly you have to do several iterations of the formula, first with a false fuel figure (to give a total weight to work with) then with the  fuel figure you get from that, then possibly again with the fuel figure you get from the second iteration.   Plus each bit of cruise (sub and super) has to be done in 30 min sections to account for decreasing weight, which on the route out of London would only be one section. 

I don't know whether CPS or PFPX does this.  Doing it manually the crew would use a best guess figure to do the calculations. 

Fascinating stuff, never an exact science and as with everything else for Concorde, EXTREMELY COMPLICATED!!

Was the PFPX figure closer to your actual fuel use?

I just wondered, that was all. I departed 09L at EGLL which takes longer of course so that would have consumed a bit more.

I don't know how CPS-X works out the fuel required but there are warnings if you're overweight or the runway length is insufficient. I'm amazed I was able to load 83+5 yesterday. The winds must have been very favourable. That's why I can't depart EGCC for TBPB as it's only 10,000ft, not the 13,500 at EGLL.

CPS-X calculated 95,440 yesterday. This morning PFPX (G-BOAC, no bias) has calculated 95,529 with no wx but only 90,139 with its weather. I don't have the FS PC turned on to get AS weather but I suspect it would be around 95,500.

In future the simplest thing would be "fill her up" for the Barbados run. I think I'll do that adding the extra fuel in the space provided in CPS-X. I'm hardly going to land overweight. :D

Have you installed v2.03 yet?

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Fraser Gale
1 hour ago, Konstantin said:

Did you never need to divert in the real life, or in the simulator?  (In other words, did you fly the real Concorde?  I think I have heard of a pilot named Adrian Smith who flew that plane - but I may be wrong). I just wonder if we have real-world Concorde pilots who are using Concorde-X...

I think you are thinking of Adrian Thomson.

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Fraser Gale
2 hours ago, AdrianSmith said:

Weather rarely makes much difference, above FL400 there is precious little wind anyway; fortunately I have never needed to divert!

The flight planning department wouldn't agree with that statement.  I agree the wind is less significant on flight time/fuel burn compared with the aircraft speed, but the temperature has a huge effect on fuel burn on Concorde. 

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Fraser Gale
1 hour ago, Ray Proudfoot said:

I just wondered, that was all. I departed 09L at EGLL which takes longer of course so that would have consumed a bit more.

I don't know how CPS-X works out the fuel required but there are warnings if you're overweight or the runway length is insufficient. I'm amazed I was able to load 83+5 yesterday. The winds must have been very favourable. That's why I can't depart EGCC for TBPB as it's only 10,000ft, not the 13,500 at EGLL.

CPS-X calculated 95,440 yesterday. This morning PFPX (G-BOAC, no bias) has calculated 95,529 with no wx but only 90,139 with its weather. I don't have the FS PC turned on to get AS weather but I suspect it would be around 95,500.

In future the simplest thing would be "fill her up" for the Barbados run. I think I'll do that adding the extra fuel in the space provided in CPS-X. I'm hardly going to land overweight. :D

Have you installed v2.03 yet?

In real life the fuel flight planning system was not linked with the runway information. It calculated the fuel for specific routes and gave you a fuel figure which the dispatcher (or crew if away from BA  station) had to make sure didn't exceed the performance/weight/balance figures for the day.  In this respect, CPS/PFPX is more advanced than the systems available for Concorde were. 

Normally there was always enough fuel to get you to BGI but the requirement to have enough fuel for a 3-engine subsonic diversion from every point along the route could bring you above the full tank figure. 

There was a story that a flight to BGI had to slow to subsonic cruise due to hydraulic issues (probably a double system failure where there isn't enough power at the PFCU's to remain supersonic) and with four engines burning fuel but flying at M0.95 the burn was huge.  According to the stewardess relaying this story, the flight engineer elected to free-fall the gear to save remaining hydraulics for brakes after touch-down, forcing him to lift the carpet in the cabin to use the mechanisms in the floor.  They made a successful landing at BGI and the crew went off to file an incident report, but there had been a ground engineer onboard who, not being directly involved, went to the nearest beach with the cabin crew.  In discussions about the incident, the engineer said "it's the closest she's come to ditching!". 

Now, it is just a story and of course years later, but if it is accurate (and it sounds plausible) I would have been looking at the data to find out why they didn't divert at the loss of hydraulics... It could have been they were just past the point of a sensible diversion, who knows but.......  

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Ray Proudfoot
31 minutes ago, Fraser Gale said:

The flight planning department wouldn't agree with that statement.  I agree the wind is less significant on flight time/fuel burn compared with the aircraft speed, but the temperature has a huge effect on fuel burn on Concorde. 

On yesterday’s flight I only made it to 58,500. The ISA Dev maxed at -10 which indicates pretty warm air. Light winds all the way otherwise I suspect some of the 83 pax would still be sitting in the departure lounge.

Yes, CPS-X is very clever taking runway length into consideration. Unlike in the real world you can depart any airport you like. Haven’t tried Innsbruck yet though. :D

That’s a great story about the gear. Imagine that today with all the camera phones!

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Fraser Gale
42 minutes ago, Ray Proudfoot said:

On yesterday’s flight I only made it to 58,500. The ISA Dev maxed at -10 which indicates pretty warm air. Light winds all the way otherwise I suspect some of the 83 pax would still be sitting in the departure lounge.

Yes, CPS-X is very clever taking runway length into consideration. Unlike in the real world you can depart any airport you like. Haven’t tried Innsbruck yet though. :D

That’s a great story about the gear. Imagine that today with all the camera phones!

The cruise climb is not accurate in P3D/Concorde X.  With that ISA and light weight you should still have reached FL600 by end of cruise. 

CPS is great for the enthusiasts who want to get in and fly as quickly as possible with the least hassle. 

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Ray Proudfoot
39 minutes ago, Fraser Gale said:

The cruise climb is not accurate in P3D/Concorde X.  With that ISA and light weight you should still have reached FL600 by end of cruise. 

CPS is great for the enthusiasts who want to get in and fly as quickly as possible with the least hassle. 

Okay. Maybe that can be improved in any future version. Am I right in thinking it’s more accurate with P3D than FSX? I ask because I think @AdrianSmithruns FSX.

Yes, CPS-X is great for flying more routes than the relatively small number flown in the real world. I wouldn’t say least hassle because all the speed, engine settings, fuel, reheat time etc. still need doing. CPS-X calculates those for the user but doesn’t set up the aircraft.

What I do like about it is you can tell it the accel point and at which point you need to be subsonic. Presumably used for more accurate fuel calculations.

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Fraser Gale
14 minutes ago, Ray Proudfoot said:

Okay. Maybe that can be improved in any future version. Am I right in thinking it’s more accurate with P3D than FSX? I ask because I think @AdrianSmithruns FSX.

Yes, CPS-X is great for flying more routes than the relatively small number flown in the real world. I wouldn’t say least hassle because all the speed, engine settings, fuel, reheat time etc. still need doing. CPS-X calculates those for the user but doesn’t set up the aircraft.

What I do like about it is you can tell it the accel point and at which point you need to be subsonic. Presumably used for more accurate fuel calculations.

It may not be linked to Adrian Smith's data - fuel burn is accurate after all.  She seems to stick around FL500 too long before starting a climb when in fact you would be burning more fuel and the weight decreasing quite rapidly at this stage, compared with at FL600 and 110T A/C weight.  

It wasn't unknown to reach FL600 quite far out from BGI with temperatures around -80C and the AFCS would be in ALT HOLD at FL600 and the A/T holding Mach 2.04 with the throttles quite far back from the stops.  You would have to notice this early because if you didn't you could really mess up the descent, as the throttles might be near the 18 degree TLA used for initial decel.  Apparently the "record holders" went past the island of Barbados still supersonic...............:D

Sectors out of Bahrain going to Singapore were well known for the aircraft climbing rapidly to FL600 and staying there throttles back for the whole of the cruise.  This was helped by the intake lip modifications that reduced fuel use at low ISA temperatures. 

It is possible to plan routes easily without CPS, but it does require a bit of extra knowledge.  The spreadsheets I use are handy as they automatically calculate distances between Lat/Long and fuel requirements, but as previously mentioned, they are only accurate for supersonic sectors. 

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Ray Proudfoot
1 hour ago, Fraser Gale said:

It wasn't unknown to reach FL600 quite far out from BGI with temperatures around -80C and the AFCS would be in ALT HOLD at FL600 and the A/T holding Mach 2.04 with the throttles quite far back from the stops.  You would have to notice this early because if you didn't you could really mess up the descent, as the throttles might be near the 18 degree TLA used for initial decel.  Apparently the "record holders" went past the island of Barbados still supersonic...............:D

Sectors out of Bahrain going to Singapore were well known for the aircraft climbing rapidly to FL600 and staying there throttles back for the whole of the cruise.  This was helped by the intake lip modifications that reduced fuel use at low ISA temperatures. 

It is possible to plan routes easily without CPS, but it does require a bit of extra knowledge.  The spreadsheets I use are handy as they automatically calculate distances between Lat/Long and fuel requirements, but as previously mentioned, they are only accurate for supersonic sectors. 

We have to rely on our weather programs to get the upper atmosphere temps right to get a performance such as you describe. I’ve only seen an ISA DEV of around -18 and usually it’s much lower. That’s for the tropics such as LAX to PHNL or JFK down to TBPB.

I’d love to have been a fly on the wall when they went passed Barbados still supersonic. There would have been a sonic boom of course. One can only imagine the fun the tabloids made of that. Lots of leg-pulling in BA too.

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Fraser Gale
21 minutes ago, Ray Proudfoot said:

We have to rely on our weather programs to get the upper atmosphere temps right to get a performance such as you describe. I’ve only seen an ISA DEV of around -18 and usually it’s much lower. That’s for the tropics such as LAX to PHNL or JFK down to TBPB.

I’d love to have been a fly on the wall when they went passed Barbados still supersonic. There would have been a sonic boom of course. One can only imagine the fun the tabloids made of that. Lots of leg-pulling in BA too.

-18 is -74C so you weren't far off -80 as I was talking ambient temperature not ISA - 80 

I've had ISA - 21 briefly before BGI. 

I think they would have known they were going to be subsonic late and turned right a bit somehow.  Mind you, the Barbadians loved watching Concorde so a boom might have gone down well...  I love all those stories, you don't get them in aviation now, it's all very sterile.  I think that's why I like Buffalo Airways (Ice Pilots fame) - Joe McBryan operates planes the old way, the way they were designed to be flown but modern authorities don't understand it, so it's frowned upon.  Even though he's (touch wood) never had a fatality in 50 years of operation, if he has one bit of paper not in the font the authorities like, they're on his back!  I bet they still let airlines fly in and out of their country that have had loads of fatalities - anyway I digress and all my own opinion... 

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Ray Proudfoot

:DCan you imagine Tom “Top Gun” Cruise piloting Concorde? Permission for a fly-by? Negative, the pattern is full.

But he goes ahead and does it anyway just like in the film! :D

I bet the Barbadians love having her there. You’ve only got to see the hangar to appreciate that.

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Fraser Gale
1 hour ago, Ray Proudfoot said:

:DCan you imagine Tom “Top Gun” Cruise piloting Concorde? Permission for a fly-by? Negative, the pattern is full.

But he goes ahead and does it anyway just like in the film! :D

I bet the Barbadians love having her there. You’ve only got to see the hangar to appreciate that.

Err, not at the moment - the Barbados experience has been closed for over a year because of lack of money.  As much as I liked the sentiment of leaving 'AE there, I never thought it would get enough visitors - small island, generally wealthy holiday makers who return every year...turned out my logic was right.  Problem is, she's stuck there!!

I've never been a T.C. fan, and at the risk of offending any Scientologists (I'm sure many of them are genuinely nice people) I think he's with that "church" for a reason...personal opinion again as I'm sure this thread will now be scanned by said organisation... :huh:

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Fraser Gale

@Ray Proudfoot if you've never seen Ice Pilots I would recommend watching it to see how real planes were flown/used/maintained.  

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Ray Proudfoot

That's a pity the museum has closed but with a limited audience I suppose it was inevitable. But you can understand why BA offered them one (or did they apply?) as the island was such a popular destination for the well-heeled.

TC is okay in some films. Mission Impossible for example. Never thought about his CoS connection. Each to their own I suppose.

I'll look out for Ice Pilots. What channel?

It's time we heard from @Michele Benedetti and the fuel bias issue. Sorry the thread got diverted. ;)

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Fraser Gale

@Ray Proudfoot agreed, we need to hear if he got his planning fixed.

Thread didn't get diverted, we were just waiting on the next waypoint :D

Can't remember what channel it was on, I bought the downloads a couple of years ago and I've watched them as many times as the ITVV Concorde DVDs. Might be on Netflix or Amazon now...

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Ray Proudfoot

In that case I might be out of luck. Don't subscribe to either. That won't change unless Amazon gets football rights (or more of them). I give enough to Sky already.

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Michele Benedetti

Well guys, I've tried everything, still, my fuel planning gives me absurd numbers...I don't know what to do anymore :(

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Michele Benedetti

No matter weather conditions, weather program, payload, alternates. route, airframe...anything will just give me around a 50 tons of fuel (TRIP) on the EGLL/LFPG - KJFK route, and little more than 70 tons for the EGLL-TBPB route

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Ray Proudfoot

@Michele Benedetti, do me a favour. Set fuel bias on G-BOAC to 0. Load EGLL-TBPB with 83 adults, 5 children. Zero cargo. Zero Wx. You should get 95T.

Please post screenshot of the PFPX screens you did yesterday. This is bugging me.

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Michele Benedetti

Will do it right now!

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Michele Benedetti

It is now telling me that fuel required exceeds maximum fuel capacity. I seriously don't have a clue of what is it doing

Cattura.thumb.PNG.f067cd792e235835f630e5bc79c14231.PNG

  EDIT: 

Exactly the same output comes if I choose the normal CONCORDE fuel policy over the LR one...

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Fraser Gale
1 hour ago, Ray Proudfoot said:

In that case I might be out of luck. Don't subscribe to either. That won't change unless Amazon gets football rights (or more of them). I give enough to Sky already.

I don't subscribe to Amazon, I just purchase the programs I want individually!  There used to be an episode filmed in Coventry on YouTube so have a search for that. 

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Fraser Gale
33 minutes ago, Michele Benedetti said:

It is now telling me that fuel required exceeds maximum fuel capacity. I seriously don't have a clue of what is it doing

Cattura.thumb.PNG.f067cd792e235835f630e5bc79c14231.PNG

  EDIT: 

Exactly the same output comes if I choose the normal CONCORDE fuel policy over the LR one...

Quit PFPX then reload - there used to be a bug in it that caused this.  Select the "L" Concorde profile to give you more fuel capacity as well as the LR fuel policy and try again.  That fuel looks correct compared with what you were getting before......

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Michele Benedetti

Tried that, no changes, still: Fuel required exceeds maximum fuel capacity

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Ray Proudfoot
15 minutes ago, Michele Benedetti said:

Tried that, no changes, still: Fuel required exceeds maximum fuel capacity

Try reducing the pax numbers. Does it work with 1 passenger?

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Michele Benedetti

Ray, not even with 1 passenger. I think it's clear now that the problem is with my PFPX setup and not with @Fraser Gale profiles

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Ray Proudfoot
15 minutes ago, Michele Benedetti said:

Ray, not even with 1 passenger. I think it's clear now that the problem is with my PFPX setup and not with @Fraser Gale profiles

Agreed. I googled the error message. See if this helps.

https://forum.aerosoft.com/index.php?/topic/120626-pfpx-issue-fuel-required-exceeds-maximum-fuel-on-board-error/

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Fraser Gale

It is very strange that you've gone from not enough fuel to over full tanks...something weird going on.  

Maybe there is a global setting in PFPX that has been changed somewhere along the line.

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Ray Proudfoot

@Michele Benedetti, check you have all the Concorde txt files in the following folder.

C:\Users\Public\Documents\PFPX Data\Aircraft

You may also have a G-BOA#.txt file in this folder.

C:\Users\Public\Documents\PFPX Data\AircraftTemplates

You should have Concorde.txt and Concorde Olympus 593-610.txt in this folder.

C:\Users\Public\Documents\PFPX Data\AircraftTypes

You should have concorde.policy in this folder.

C:\Users\Public\Documents\PFPX Data\FuelPolicy

You're getting different results to yesterday. What have you changed?

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Ray Proudfoot

Got it!  Change Cruise Altitude/FL to Max and Step Climb to No.

If you don't you get that message.

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Fraser Gale
20 minutes ago, Ray Proudfoot said:

Got it!  Change Cruise Altitude/FL to Max and Step Climb to No.

If you don't you get that message.

That's different to v1.28 then...it makes no difference in my version!

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Ray Proudfoot
1 minute ago, Fraser Gale said:

That's different to v1.28 then...it makes no difference in my version!

All the more reason why you should update. http://www.flightsimsoft.com/downloads/

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Ray Proudfoot
1 minute ago, Fraser Gale said:

I'm going to wait to see if the issue here is fixed first!

It will be. I changed just those two settings and got the same message as Michele. Switched back to mine and it solved it.

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Michele Benedetti

Ok, tried what Ray said in the post above. It is now giving me a release of 91.8 tons without any weather and with 100 pax (using G-BOAC)! That's too little fuel for sure.

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Fraser Gale
14 hours ago, Ray Proudfoot said:

It will be. I changed just those two settings and got the same message as Michele. Switched back to mine and it solved it.

You know how you said this @Ray Proudfoot......

Well...

5 minutes ago, Michele Benedetti said:

Ok, tried what Ray said in the post above. It is now giving me a release of 91.8 tons without any weather and with 100 pax (using G-BOAC)! That's too little fuel for sure.

:huh:

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Ray Proudfoot
26 minutes ago, Michele Benedetti said:

Ok, tried what Ray said in the post above. It is now giving me a release of 91.8 tons without any weather and with 100 pax (using G-BOAC)! That's too little fuel for sure.

Not enough info. What aircraft? How many pax? EGLL-TBPB presumably. I'll try what you supply. Screenshot would help.

LATER: 89.2T with no Wx and 90T with AS weather. Presumably winds and temps are more favourable today.

PFPX_Concorde.jpg

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Ray Proudfoot
2 hours ago, Michele Benedetti said:

Ok, tried what Ray said in the post above. It is now giving me a release of 91.8 tons without any weather and with 100 pax (using G-BOAC)! That's too little fuel for sure.

I asked for info you had already provided so sorry about that. 100 pax on the Barbados run is too many. I could never get CPS-X to accept that many.

Providing you have set the fuel bias to zero and nil wx it's out of my hands. The issues are between PFPX and Frazz's data. What seems fine one day then appears odd the next.

I tried using TFFF as the alternate but too much fuel was required so it didn't generate a schedule.

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Fraser Gale
15 minutes ago, Ray Proudfoot said:

I asked for info you had already provided so sorry about that. 100 pax on the Barbados run is too many. I could never get CPS-X to accept that many.

Providing you have set the fuel bias to zero and nil wx it's out of my hands. The issues are between PFPX and Frazz's data. What seems fine one day then appears odd the next.

I tried using TFFF as the alternate but too much fuel was required so it didn't generate a schedule.

Has it ever been fine though?  

85 was maximum PAX for BGI  as a round figure. I can't really help because the profiles work in Ray's  v2.03 and in my v1.28 so I'm at a loss other than saying uninstall PFPX and reload everything.

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Ray Proudfoot
9 minutes ago, Fraser Gale said:

Has it ever been fine though?  

85 was maximum PAX for BGI  as a round figure. I can't really help because the profiles work in Ray's  v2.03 and in my v1.28 so I'm at a loss other than saying uninstall PFPX and reload everything.

It seemed okay in my post here. 95T with 83 adults and 5 sprogs.

 

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Fraser Gale
1 hour ago, Ray Proudfoot said:

It seemed okay in my post here. 95T with 83 adults and 5 sprogs.

 

Yes, it was ok for you but I meant did @Michele Benedetti ever get the right numbers? In Michele's case the numbers haven't been right at all for some reason. 

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Michele Benedetti

Exactly, I'll try to uninstall and re-install PFPX and the profiles. Thank you both for your help! :)

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Fraser Gale
15 minutes ago, Michele Benedetti said:

Exactly, I'll try to uninstall and re-install PFPX and the profiles. Thank you both for your help! :)

I don't think we've been any help.... but we're trying!

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Michele Benedetti

I'll try to unistall and re-install everything in the next few days, now I'm a bit busy with my university exams...

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