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ksfo-vhhh Range for 747-400

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I was flying this route the other day with a fuly loaded 747 and found that I was unable to make it with the fuel on board. That can't be right, can it? I was using Active Sky, with a FSBuild route that was (as far as I know) fairly true to life. There was a strong headwind for an average of 76 kts, which a fuel planner told me made the 6300nm range essentially into a 7200nm route(or something like that).I know United flies this route with a 747. Are there times where they are unable to make it? I suppose, more likely, the have better route planners that I have and manage to avoid this much headwind. Has anyone had a similar problem? And what should the fuel flow be for a fully loaded 747 in lbs/hr?- daniel

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Guest neerajpendse

I would ask the following:1. How much fuel? 100%? 2. Did you use FMC Cost Index at all?3. What flight level?4. Did you monitor FF, distance to go and fuel remaining? etc calculations?5. Where did you end up landing, anyway?Regards,- Neeraj.

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100% Fuel, Cost Index was 100, I believe. FL280 until I could reach FL360. I did monitor fuel, etc.I did not land at an alternate, actually, just added fuel, and then landed at VHHH.- daniel

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You said you flew a fully loaded 744. Does this mean full passengers and cargo? If so, you need to reduce at least the amount of cargo you are carrying. For very long flights, airlines don't carry a full load of cargo. Just the passenger's luggage and whatever else will fit without going over the MTOW. Remember, the more weight you add, the less range you'll have despite fuel. Also remember that fuel is weight too.Ryan GamurotLucky to live Hawai'ihttp://www.precisionmanuals.com/images/forum/supporter.jpg


Ryan Gamurot
 

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Oh yes, of course... I should have mentioned this. I was not above MTOW, but at around about 99% MTOW, which is what I meant by fully loaded. I always follow SOPs quite thoroughly. I also download NAT and PACOTS tracks, fly SIDs, fuel plan, follow the most economic altitudes, etc. I'm fairly sure that otherwise I'm proceding as I should. So I suppose that other than heavy headwinds, I should be able to make this route within maximum range, correct? And an average (total) fuel burn of around 27000lbs/hr (that's all 4 engines, mind you) is about normal?- daniel

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You may also want to lower the Cost Index to around 50% or less.Scott


Kendall S Mann

Still Telling Pilots Where To Go!!

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>Oh yes, of course... I should have mentioned this. I was not>above MTOW, but at around about 99% MTOW, which is what I>meant by fully loaded. Good. Now, I'm assuming that by not having enough fuel, you meant that the FMC said you would have 0.0 pounds upon touch down. Looking in your LEGS page, where do you run out of fuel. NOTE: You have to press RTE DATA at the bottom right of the LEGS page first.> I also download NAT and PACOTS tracks, fly SIDs, fuel plan,>follow the most economic altitudes, etc.Do you allow FSBuild to self-generate a flight plan, or do you import it from another source and have FSBuild put it all together in PMDG/FS9 format? Also, by, "follow the most economic altitudes," you did mean the ones in the FMC, right? I mean, when it said step climb NOW, or a little before, you step climbed to that ALT right?>So I suppose that other>than heavy headwinds, I should be able to make this route>within maximum range, correct? And an average (total) fuel>burn of around 27000lbs/hr (that's all 4 engines, mind you) is>about normal?This may sound tedious, but you use AS6 right? Print out the Navlog and enter the winds into the FMC. This will give you a more accurate fuel reading in the FMC. Unfortunatly you can't automatically load the winds, it must be done manually. But if you do have the same wind direction/speed for multiple waypoints one after the other, you can leave the W in place. Also, did you use FSBuild for fuel information? If so, start AS6 first and make sure it's feeding WX to FSBuild. Under OPTIONS, look for ActiveSky 6 and make sure next to it, the AS6 path is listed. If not, hit browse and go to your modules folder and select AS6. Under AIRCRAFT, make sure you entered the correct weight information. Also, did you download the PMDG 744 performance data from the website? This will tell you if you need more fuel. Some times it tells me I need more fuel I can hold. I looked up the distance and although you have 100% fuel onboard, with a range of ~6300nm, you may still need to cut back on cargo. Although the listed range is >7000nm, that's only with a very light load. Finally, different people use different COST INDEX numbers. I personally use 70 units for my long haul flights. For regular flights with a range of around 1500 to 3000 or 4000 I use between 70 and 90. If it's really sort, like less than 1500nm, I use anywhere between 150 and 220.I hope this all helps.Ryan GamurotLucky to live Hawai'ihttp://www.precisionmanuals.com/images/forum/supporter.jpg


Ryan Gamurot
 

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Okay, will try all this, thanks. The only thing I can think is that I had too much cargo aboard. I will try and enter all the winds (I've never done this before, probably because it was a little tedious). But I suppose I have my answer; that a lot of people are flying this route without trouble.Thanks to all.- daniel

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Hello Daniel,Just thought I'd add a bit based on my experience with the PMDG744, having flown the route in question, as well as ORD-HKG, LAX-HKG, etc., more times than I'd care to admit :)First, these routes absolutely push the limit of the 744, with any useful payload, and quite obviously require careful planning, and a little cooperation from the weather, to even have a shot at making it non-stop. To answer one of your questions, UA, CX, et al will often have to make a tech stop for fuel when conditions are less than favorable. There will be times when you will have to either reduce the payload to such an extent as to make flying the route pointless, decide to tech stop, or simply fly another route and wait for better weather.I also use FSBuild and AS, together a powerful combination, that will yield successful results about 90% of the time. Last year, I spent quite awhile recording performance info, etc, from my trips US-Asia (though I haven't done UA895 in a while now, the planets only seem to align about twice a year for that one). I really wanted to nail down a good profile for the Queen to use with FSBuild. After all, it's all data-driven, right ? Get good data from the sim and plug it into FSBuild, should be good to go.Towards the end of my testing, I was really banging my head against the wall, as I had a profile that would work really, really well about half of the time, but leave me a good 8-10K lbs short the other half. Finally, after pulling my head out of my nether regions, I realized one important limitation of FSBuild that will only show itself, in any meaningful way, when pushing the margins like I was.Temperature.There is no way to have FSBuild consider temperature when planning, and above ISA mid-to-high level temperatures will wreak havoc on your fuel margins. Spend a few hours at FL300 at ISA+10 or +15 and look at your FF, not to mention, it takes a good deal longer to get up there.When I was testing, I setup the profile, initially, in ISA conditions, and then took that data and tweaked with actual flight data. I had to compromise, eventually settling on data that left me very close on those hot days, and a bit over on fuel when temps were ISA or below.Also, the profile from the FSBuild website has some bad data for altitude/climb capability, (which is actually what started me down this road in the first place)and will plan fuel with you lower than whatever your optimum FL would be, throwing things off even more.I also went a bit opposite of other posters here, and optimized my profile for a CI of 160/~M.860.I'm very, very happy with the results, and have complete confidence now in the numbers it generates. It is ver close on TOC and step climb predictions as well, whichis nice. In fact, the only time it's ever "off" for me anymore is when I nap through my step climbs :)I'm more than happy to share, drop me an e-mail if you're interested.


Regards,

Brian Doney

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Hi Brian,Yes, I would be very interested, thanks. I'll send you an email.You might have to explain it how to apply it all to FSBuild, as I don't use (or trust) the airliner profiles that comes with it. When you speak of ISA I assume you mean 15C at sea level, with an ELR of 1.98C per 1000 ft. Is that correct? Colder air is denser, and therefore easier to climb in, but heavier to fly at altitude in. That makes sense to me, and something I had not really considered before.I'm taking a commercial aviation course/licence, with many of the instructors that fly for Air Canada and their feeders. We're just getting in to weather in flight planning, although I'm sure it will mostly pertain to the Cessnas we fly for training. I know that all the flight plans generated for them are done by dispatchers use some crazy software, and I've been given some flight plan dispatches for this course. The one I'm holding right now is a Dash 8-100 plan from Toronto to Baltimore, and it's about 20 pages long. Absolutely amazing stuff!! It's so complicated (and so in-depth) that I can't imagine how you'd be able to reproduce it without such software. Their focus is obviously down to the closest pound of fuel they can get to... Which seems like the issue with these ultra-long routes. At any rate, I will email you and see if I can wrap my head around the data you have. Thanks again...- daniel

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Ryan,Well, Ive offered a few times before, and gotten very little response(one person :) )RE: an OPS article, well, not entirely sure what that would entail, and I've gotta believe there's someone more qualified than me on the subject ?


Regards,

Brian Doney

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