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Guest Ptroinks

Yet another "Insufficient Fuel" problem...

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Guest Ptroinks

Hi, all!Yes, there are quite a few posts on this forum regarding the Insufficient Fuel FMC message. It appears that none of these posts can help me, so I have to start another thread.I'm flying the 747-400, and my flight plan takes me from LFPG (Paris) to KLAX (Los Angeles). Payload weight is 127280lbs. The route was made using FSBuild, and the total distance of the flight is 4972nm. My fuel planner gives me a total fuel load of 291573lbs (after correcting for headwind). The 747 manual tells me to put (minimum landing fuel + alternate fuel + contingency fuel) in the FMC reserves, and that gives me 53873lbs of reserve fuel. I get the Insufficient Fuel FMC message even before I start taxiing from my gate at LFPG, and I have never had this problem before with the 747, although I have flown across the pond before, using the exact same fuel planner. Am I doing something wrong? I know that the FMC message is just advisory and I am confident that I can make it from LFPG to KLAX with lots of fuel to spare, but if that message appears, something must be off, and being somewhat of a perfectionist, I'm not going to start flying this route until I have this problem sorted! I hope someone can help me with this. If not, it appears that I'm stuck in Paris ;).

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Which contingency fuel are you including in the FMC reserves?The reserve figure should comprise of your min landing fuel at alternate plus any approach fuel needed at the alternate plus the B to C fuel (from destination to alternate) plus any contingency fuel carried for B to C only.So in summmary.Reserve fuel equals:B to CB to C contingencyAlternate approach fuel (if req)Min landing fuel.You may find that the winds that FSbuild uses and what FS9 uses are different as well and this might be giving you a stronger headwind component or weaker tailwind component. If this is the case you will need more fuel. I have heard that FSbuild is not that accurate for fuel planning for the PMDG 747. On the progress page compare your arrival fuel with the reserve fuel on the PERF page. Also check that you are starting off the flight at optimum altitude and that the step climb has not been deactivated. Where did you enter the initial cruise altitude? Try changing the cost index to a lower value. Prior to departure your fuel at destination should at least equal your FMC min reserve figure plus the A to B contingency plus any overfuel. You may have to increase your fuel load so that the fuel at destination is greater than reserve.CheersSteve


Cheers

Steve Hall

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Guest D17S

This is from a previous post, but it might be fun to try here: If you want to experiment, try setting up FSB to use Active Sky 6 (AS6) weather. It's a royal pain, but once you get things all plugged in right, FSB will use the various AS6 winds aloft data presentations build your flight plan in FSB. Let FSB calculate its own step climb points, etc. I really like FSB's "convert to .PDF" option. So let FSB print you out a nice .PDF flight plan.FSB will also output the flight plan in PMDG format, so load it up into the 744s FMC. Now take your FSB flight plan in hand and manually enter the FSB/AS6 winds aloft data -way point by waypoint- into the 744's FMC's legs page/winds aloft data entry points. Let the FMC 'do it's thing' calculating step climbs, etc. The PMDG 744's FMC will get you a burn number. Check the FMC burn against the FSB burn. Remember, you're using the same flight plan and the same winds. I was getting a significant difference. The FMC ended up being right, so here's a suggestion: Use of FSB ONLY as a handy way to calculate your 'additional required' fuel (Steve gave you the drill there). Use the 'additional fuel' number from the FSB plan, plus the FMC's calculated burn. Now add those two numbers up and fuel you aircraft to that fuel load. Now fly with AS6 running, hooked-up and providing MSFS the winds you entered into the 744's FMC. This should be a totally boring and monotonous flight, but fly it just like a crew would. Note your time, winds, temp and fuel remaining at each waypoint. Continuously compare those numbers to what the FMC had projected. It should stay right on the nose.-- Note: Make sure you know if you are using real time or historical winds from AS6. Historical winds should simply be re-created in MSFS exactly like what you entered into the FMC. If this is the case, big yawn. But if you are using Real Time winds, they might shift. I think AS6 updates winds every 12 hours. If you fly through one of those cycles, you might get a whole different wind environment. Now we're having fun. "Gander radio, Gander radio, D17 declaring fuel emergency!" --Essentially, this drill is just checking how well the PMDG airplane interfaces with the AS6 generated, MSFS environment. You'll be able to tell how well things are going by watching actual vs. projected. Actually, you'll be bored silly . . . with any luck . . . just like a real pilot. You wouldn

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Guest Ptroinks

I just wrote another post to clarify things, but after posting, it doesn't show on the forum, so I have to start over :~P.Here's how I calculate my reserve fuel:Minimum landing fuel: 24000 lbs.Contingency fuel: 18000 lbs.Alternate fuel: 11695 lbs.This gives me 53695 lbs. of reserve fuel. This differs some from the figures I gave in my first post because I had to recalculate.I don't use FSB for anything except creating the route itself. I import the created route into Active Sky to get the average route winds, and I then use a fuel planner application for the... well... fuel planning ;). I just realised that I made a mistake with my fuel calculations (keep reading!). There is a checkbox in the fuel planner with the text "Enable fuel burnout correction for deviation abovebelow 475000lbs landing weight". When checked, I get 78348 lbs. more fuel in the "total fuel load" (giving me over 875000lbs GTW, so I have to throw out some of the passengers ;)). I remember checking this box in my other long haul flights, possibly explaining the "insufficient fuel" message I got yesterday, but I honestly have no idea what this does to the calculation. I've added two pictures showing the fuel calculation before and after checking this box. I hope someone can tell me what effect this checkbox has.http://forums.avsim.net/user_files/158166.jpghttp://forums.avsim.net/user_files/158167.jpg

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Guest benhoffman

In the world there are THREE, yes count em, THREE nations where the regulators regulate that the Dispatcher and Captain share joint responsibility for flight planning and execution.They are the United States, Canada and China.I take great pride in planning and executing flights so let me share some of my knowledge.I haven't the foggiest clue where PMDG plucked the 24,000lb for MLF or the 18,000lb an hour burn rate for holding out of but I'll say I'm skeptical of those numbers.Because all the different regulators (FAA/JAR/CAA/CAAC/IAA etc) have varying fuel laws (as our drivers will tell you) you are required to plan any of the following as your RESERVE FUEL, depending on which rule you use.- 10% of A to B- 5% of A to B- 45mins cruise fuel- 10% of A to B + 30mins- 5% of A to B + 45mins - 10% of Class II Nav time + 30 mins ...See? Thats a lot of varying numbers, and I'm sure unless you are going straight from point A to B and NOT redispatching, that one of them MIGHT equal 24,000lb, but not likely.I'm also not in possession of a -400 QRH but unless you're holding at about 1,000ft at MLGW I'd bet $10 you will not burn 18,000lb holding for an hour. I could be wrong tho.I am not current on French (CDG-LAX strikes me as an Air France flight so I'll use that assumption) or JAR regs but here is what, ss the Dispatcher, I am required to plan as far as fuel load goes according to the FAA rules (FARs) - BURNOUT fuel rom A to B - ALTERNATE fuel from B to C (if one is specified) - 10% of BURNOUT as CONTINGENCY - 30 min of RESERVE [holding] fuel at 10,000ft at landing weight United says you cannot plan to land with less than 1hr of fuel (on flag & supplumental flights) and that EXTRA fuel must be boarded if that's the case.Steve must always arrive at his destination with again, not less than one hour of fuel endurance, but I think that's a company thing.To calculate for headwind, I use ActiveSky's excellent NavLog feature (import the .pln file, process and look down the bottom for the AVERAGE WIND COMPONENT)Lets say your route is 3,000nm long and is planned for 11hrs but your average wind component is a headwind of 23kts. 23x11 = 253 + 3000 = 3253nm. Thats your WIND CORRECTED distance and should be used for fuel planning. You must also consider things such as temperature at cruise level, weight, weather deviation etc etc etc ... all a very fun subject but at United, the MINIMUM FUEL you can land without having to SERIOUSLY think about declaring a FUEL EMERGENCY is the FAR RESERVE fuel (30mins holding at 10,000ft) on an international flight, so I enter that number plus HALF of my 10 PCT figure into the RESERVE feild.QANTAS on the other hand does not require holding or contingency fuel so you can immagine the hair thier Dispatchers have on thier head after such detailed NOTAM/delay and weather briefings, I read this about a year ago so it might have changed. I know this is looooong and technical but I hope it helps.

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Hi,I had this problem a couple months ago when I flew from EGLL to KSFO. I received the message on the gound during taxi (strange), and yet I knew I loaded the correct amount of fuel. I use the same fuel planner as you, and I wasn't quite sure why I received the message. The even stranger thing is that after I took off, and got into CRZ, I checked the FMC, and it showed plenty of fuel at landing. So, either it was an anomoly, or I did something wrong that I couldn't see.- John>Hi, all!>Yes, there are quite a few posts on this forum regarding the>Insufficient Fuel FMC message. It appears that none of these>posts can help me, so I have to start another thread.>>I'm flying the 747-400, and my flight plan takes me from LFPG>(Paris) to KLAX (Los Angeles). Payload weight is 127280lbs.>The route was made using FSBuild, and the total distance of>the flight is 4972nm. My fuel planner gives me a total fuel>load of 291573lbs (after correcting for headwind). The 747>manual tells me to put (minimum landing fuel + alternate fuel>+ contingency fuel) in the FMC reserves, and that gives me>53873lbs of reserve fuel. I get the Insufficient Fuel FMC>message even before I start taxiing from my gate at LFPG, and>I have never had this problem before with the 747, although I>have flown across the pond before, using the exact same fuel>planner. Am I doing something wrong? I know that the FMC>message is just advisory and I am confident that I can make it>from LFPG to KLAX with lots of fuel to spare, but if that>message appears, something must be off, and being somewhat of>a perfectionist, I'm not going to start flying this route>until I have this problem sorted! I hope someone can help me>with this. If not, it appears that I'm stuck in Paris ;).


Boeing777_Banner_Pilot.jpg

 

- John Drago

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Looking at a couple of BA flight plans - planned landing fuel tends to be about 13-15 tonnes. It consists of:- approx. 4200kg holding (about 30 minutes at 1500ft I think)- approx. 4000kg contingency (I think they maybe have 10% to a maximum of 4000, but I could be thinking of somewhere else)- alternate fuel (usually around 7000 for a diversion to manchester from london)That gives you (all going perfectly) a planned landing fuel at destination of 15200kg (33,500lbs). As you can see it is a lot less than that which you are taking!As you can see, they don't take unnecessary amounts of reserve fuel. It doesn't give you a huge amount to play with.For example, to arrive at manchester with 7500kg of fuel left (not a lot, considering minimum is about 5500kg), they would need to divert from London having only burnt 700kg of fuel holding or whatever (again, all going perfectly).I am sure the info is correct, and I am pretty sure I have explained it right, but feel free to correct me anyone who knows better!!!RegardsRudy


Rudy Fidao

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Guest D17S

"Hook up AS6 to FSB?" Ahhh . . . well, here are my notes. It was a real drill to get it to work. The following is a forum exchange I found via google. Ernie is FSB's author. By some miracle, I was able to get it to work by getting the "basic idea" from this. If you can figure it out again, I bet we all'd all appreciate a perfectly working, step by step lay out. "So, Mr. Phelps, your mission, should you decide to accept . . . . of course, we will disavow any knowledge of your actions if any of your team is caught or . . ." Good luck.-- Hello I have upgraded to the latest active sky awhile back and also purchased fsbuild 2.2 some time ago.. I put FSBuild on the back burner for awhile and no I am back to it. I am trying to get it configured to take in my winds aloft data. I did have it pulling my winds aloft data with the active sky version 2004.5. I do not understand what I could be doing wrong. Here is my FSBuild Config[FSBUILD]AUTOREFRESH_DELAY=1MAGYEAR=2005SBPC_SERVER=www.vatsim.netROUTELINE=1NATRAKURL=www.natroutes.glideslope.de/html/nats.php3WEATHERPROG=ACTIVESKY[MS-FLIGHTSIMULATOR]FS_HOME=C:PROGRAM FILESMICROSOFT GAMESFLIGHT SIMULATOR 9SB3_FP=C:PROGRAM FILESMICROSOFT GAMESFLIGHT SIMULATOR 9SQUAWKBOXACTIVESKY=C:PROGRAM FILESMICROSOFT GAMESFLIGHT SIMULATOR 9MODULESASV...Could someone please educate me on this issue please.Your 'ACTIVESKY' reference is to the first WxRe version.For Activesky2004 and above, use the ...AS2004-ASV=reference in the .cfg file.The 'WEATHERPROG=' option should also readWEATHERPROG=ACTIVESKY2004-ASVIf you are reference to a version of Activesky later than the orginal WxRe version.Quote:P.S. Are there any way I could create a burn table for my cessna208 grand caravan deluxe or get ahold of something that installs my cessna208 in FSBuild?At the moment no, unless we or someone else comes up with performance data we can use to add the 208 to Fsbuild.Fsbuild reads the latest 'current_wx_snapshot.txt' file in active sky so that is the file to check to see if Fsbuild is reading the winds aloft data correctly.Also the Navlog displays the wind direction and speed at each waypoint.You can also select the 'Replace ETA column with WxSta' on the Build Options menu to see which weather station winds were used at each waypoint.Regards.Ernie.Working fsbuild2.cfg file contents:[FSBUILD]AUTOREFRESH_DELAY=1MAGYEAR=2006AIRCRAFT=B747-400 PMDGSBPC_SERVER=www.vatsim.netROUTELINE=1NATRAKURL=www.natroutes.glideslope.de/html/nats.php3WEATHERPROG=AS2004// note: As long as the "weatherprog=XYZ" and "XYZ=C:PROGRAM FILESMICROSOFT GAMESFLIGHT SIMULATOR 9MODULESASV6" XYZ entries match, it will work fine. [MS-FLIGHTSIMULATOR]FS_HOME=C:PROGRAM FILESMICROSOFT GAMESFLIGHT SIMULATOR 9AS2004=C:PROGRAM FILESMICROSOFT GAMESFLIGHT SIMULATOR 9MODULESASV6[FLY!][PS1][X-PLANE][sTARTUP]STEP_CLIMBTOC_TODINCL_CROSSING_ALTSCLEARMAP_BEFORE_BUILDDISPRTEWPTSONMAPINCL_NL_PLTINP_HDRSWINDS_ALOFTWXFORETARVSM_FLFS2000_GPSFSNAVLDS767PMDG737NGAUTOREFRESH_ONEnd notes -- I

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>fuel calculation before and after checking this box. I hope>someone can tell me what effect this checkbox has.I have no clue why the author of this program decided to leave this option to the user and provided this checkbox. This checkbox should ALWAYS be checked or you end up with unsufficient fuel - fuel consumtion depends of course on weight and if you leave the box unchecked you end up using wrong landing weight in your calculations.Michael J.


Michael J.

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Guest benhoffman

If the WX is bad at Heathrow then the BA Dispatcher would add more fuel for the SPECIFIC purpose of weather holding.If the weather in LHR is perfect but they're having a massive traffic problem, you can quite possibly delete the alternate of Manchester and use that fuel to hold; I know that's legal at least at United.For some reason if we had to do a missed approach in bad weather the crew would get on the horn to thier Dispatcher and have a talk about what to do. We could do something like conduct a second approach and if you still can't land, go to Manchester.If the WX was good, then maybe do the above of delete Manchester and use that fuel for holding until we can get back on the ILS again.Its amazing what Dispatcher and Captain can work out :)

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Guest Jock in a Frock

> so I have to throw out some of the>passengers ;)LMAO, I've got this image of you walking through the cabin shouting "Hey, Fatty, get the f*** off my plane or the rest of us ain't gonna make LAX!":)Andy Scholes.

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We always carry an alternate (B to C fuel). If the weather at destination is below alt minima then the alternate has to be one where the company would like the aircraft to be should it divert. If the destination weather is fine then we can use a "technical alternate". These are closer to destination but have lesser pax handling facilities. We still have to arrive at destination with 60 min of fuel if using a close tech alt.We carry the following:A to B A to B Contingency 2%Approach fuelB to C fuel (to alt airfield)B to C contingency 2%Vis app fuel (or Instru. if weather requires)30 min holding at 1500 ftPDA on all the above (performance deviation allowance) Each aircraft is monitored for conformance to book figures and an adjustment made to correct to book figures.In addition to the above we have to ensure we cover the 3 eng, 2 eng and 4 eng depressurised scenarios. Additional fuel may be required to cover this. Usually only when the distance between the last airfields is large or the dest alt close to the arrival airfield.The capt can carry extra as he sees fit (ie. weather deviation or anti ice fuel, extra holding extra)In flight the weather at destination is monitored and if the fuel useage inflight is greater than planned then either a closer alternate is looked at or you can use the B to C fuel component to get to destination. Naturally there are airmanship considerations here ie. weather trends and forecasts and single runway use and traffic volumes etc.For flights into LHR we may nominate Stanstead or Gatwick as ATC alternates but carry Manchester as the fuel alternate. This gives a good degree of flexibility.This system works very well. The met info now is usually very accurate (lots of datalink capable aircraft pumping out lots of met data).CheersSteve


Cheers

Steve Hall

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Guest benhoffman

Steve, thats a very interesting fuel policy.I note you say a contingency of 2% on both burnout and alernate fuel, a contingency on the alternate fuel I've never seen before.I will be on NZ8 to SFO in a few weeks (ah, the -400 awaits!) so I'm curious, what do you nominate as the alternates? Personally I use OAK/SMF or if things were really crappy I'd maybe use LAX PDX or LAS.Any luck in finding out what the ANZ OpSpecs says re the FAR requirements for the US flights? I know FAR 121.627 says 10% of burn as cont'y unless OpSpec says lower, assuming you have lower.I'd also love to know what NZ uses as its ETOPS alternates on the AKL-LAX, AKL-SFO, LAX-LHR flights as AKL-SFO on a 777 sounda like you'd have to either use ETOPS207 or some pretty far out places as your RALT's.I also take it these numbers are only for international flights and the domestic flights are not subject to them?Thanks, I'll be looking for you on NZ8 :)

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Guest Ray51

I fly mostly as a frieght dawg so I am almost always near max weight.I plan fuel by first calculating my fuel to destination corrected for weather. Next I calculate fuel from destination to my alternate (I try to use a company airfield as the alternate when possible, have to watch the RWY length here.)I then add in holding fuel for both my destination and my alternate figuring 30 min at best holding speed using cruse altitude for destination holding and an intermediate altitude for alternate holding. I next add in approach fuel for both destination and alternate. Finally I add taxi and 30 min if landing in daylight and 45 mins if landing at night required extra fuel.This allows me to hold enroute, make my approach into my destination and be diverted by the tower, hold or be vectored for weather/ traffic at my alternate and still have enough fuel to approach and land. Being heavy I can burn alot of fuel when being vectored in the class B airspace.Ray

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