Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Technology Science

Fuel Loss May Cut Short GlobalFlyer's Journey 317

Posted by timothy from the knock-on-wood dept.
chris mazuc writes "Apparently the Virgin Atlantic GlobalFlyer has lost 2,600 lbs of fuel and might be forced to abort the attempt." According to the article, "Jon Karkow from Scaled Composites was unable to say whether it was due to leakage or evaporation. "We really don't know what it is... It's more than likely a system issue, such as a fuel venting line. It's been very puzzling for us, and we saw it quite early on.".
This discussion has been archived. No new comments can be posted.

Fuel Loss May Cut Short GlobalFlyer's Journey More

Fuel Loss May Cut Short GlobalFlyer's Journey

Comments Filter:

  • Rigorous Testing? (Score:5, Interesting)

    by ackthpt ( 218170 ) * on Wednesday March 02, 2005 @03:19PM (#11826063) Homepage Journal
    "We really don't know what it is... It's more than likely a system issue, such as a fuel venting line. It's been very puzzling for us, and we saw it quite early on.".

    An amount of fuel was predicted to be lost due to evaporation, but as the aircraft's tanks had not been tested at full capacity , Mission Control were unable to predict the exact amount that would be lost.

    Uh .. I don't think I'm quite as eager as I once was to go up on Virgin Galactic* The Global Flyer would more appropriately be named The Bleeding Edge.

    *The joint venture between Rutan's Scaled Composites and Branson's Virgin.

    • Bit of a difference... (Score:5, Insightful)

      by lxt ( 724570 ) on Wednesday March 02, 2005 @03:24PM (#11826117) Journal
      ...there's a difference between the Global Flyer and the Galactic, in that the Global Flyer is a non commercial interest. The galactic carries paying passengers - I doubt the Global Flyer will ever do such a thing, given its capacity.

      Further more, the global flyer has been designed for a speed record attempt, and so must be at the bleeding edge to beat what's gone before. Sure, the Galactic would also be a record breaking craft, but it isn't going to be chasing speed records. The Global Flyer has to be the fastest machine, and therefore utilise more unproven technology than, say, the Galactic.

      • Re:Bit of a difference... (Score:5, Interesting)

        by ackthpt ( 218170 ) * on Wednesday March 02, 2005 @03:29PM (#11826175) Homepage Journal
        The Global Flyer has to be the fastest machine, and therefore utilise more unproven technology than, say, the Galactic.

        Sure, sure, but they didn't test at full capacity? Cripes, that has nothing to do with bleeding edge engineering, that's just being in too damn big a hurry. I think quite a lot of /. readers are familiar with the phrase, "You can have it done right, or have it done right now, take your pick."

        That they went for "right now" suggests there's been corners cut and we're on the verge of (what May 15th?) NASA restarting the shuttle program after much soul searching. What a fine example this [globale flyer] team has set.

        • Re:Bit of a difference... (Score:5, Informative)

          by sacherjj ( 7595 ) on Wednesday March 02, 2005 @03:34PM (#11826212) Homepage
          Actually they are testing it at full capacity. Right now. If it works, they finish the flight. If it doesn't, they modify the system. If you remember, the voyager only loaded full fuel on it attempt flight. And they pretty much ground off both winglets. Yet, the craft was still ok to fly around the world and set the record. Sometimes you have to take some exucated risks to set records.

        • Re:Bit of a difference... (Score:5, Interesting)

          by einhverfr ( 238914 ) <chris...travers@@@gmail...com> on Wednesday March 02, 2005 @03:35PM (#11826228) Homepage Journal
          I thought about this two and I decided that there was a simple reason---

          Taking off fully loaded was supposed to be the most dangerous part of the flight. How easy would it be to land with that much fuel? Is that something that should be tested? Or saved for an emergency?

          I doubt that the airplane was designed to easily land when fully loaded without emergency measures in place
          • I would bet they have a way to dump extra fuel.

          • you are right (Score:5, Informative)

            by willCode4Beer.com ( 783783 ) on Wednesday March 02, 2005 @04:23PM (#11826689) Homepage Journal
            Actually, due to a design to keep the structural mass low and due to the mass of the fuel, it can't land safely with a full (or even half) load of fuel.
            The plane just isn't strong enough. Making the plane stronger would make it heavier, and a heavier plane would require more fuel. Its a compromise that had to be made.
            On a side note, they actually wanted to use a different turbine that was more fuel efficient but, were unable to locate one. So since the turbine they are using consumes more fuel, more compromises had to be made in the design.

            With a flight like this, you have to get rid of every last once of weight possible.

            • Re:you are right (Score:4, Informative)

              by einhverfr ( 238914 ) <chris...travers@@@gmail...com> on Wednesday March 02, 2005 @04:56PM (#11827045) Homepage Journal
              The structural issue had not occurred to me. I was looking at the wings which are evidently designed for fuel-efficiency rather than an ability to maintain lift while moving slowly with a heavy load. This means two things: 1) Higher take-off speed/long runway requirement and 2) higher landing speed/long runway requirement.

              Worse, this problem becomes worse as load is applied. This is because stall speed is dependent on the point where the lift is minimally equal to the weight of the aircraft. So higher load means higher stall-speeds, hence higher-speed takeoff and landing. Landing is more sensitive to this because the aircraft is slowing down to its stall speed rather than accellerating past it as in takeoff.

              Most commercial aircraft get around this problem by morphing the shape of their airfoils in order to provide more lift during takeoff and landing (allowing for shorter runways and slower speeds) but I don't see that on this airplane. I could be wrong on this point, but I doubt it. Otherwise I doubt that the choice of runway would have been made primarily on the basis of length.

              So if this plane is landing with 9 tons of extra fuel, assuming it is built out of a magical indestructable material, you still have the issue that you have a much larger ammount of kenetic energy because the plane is not only more heavily loaded, but also moving significantly faster. So it is harder to slow the vehicle down.

              • 747 does this too (Score:3, Informative)

                by lommer ( 566164 )
                Extra fuel is not a problem for landing - you just dump it overboard at 10,000 feet before you descend to land. This is standard operating procedure on the boeing 747 - it isn't certified to land at a full fuel+passenger/cargo load (landing gear will collapse) so once it takes off it has to get rid of fuel before it lands again one way or another. So if some dude has a heart attack right after takeoff, they will climb the airplane up and dump the fuel before landing again (they have to be at a certain heigh
        • Firstly, as has been mentioned, this IS a test flight, with full fuel capacity.

          Secondly, the reason they went for "right now", in addition to their feelings of readiness, had to do with taking advantage of tailwinds and updrafts available at this time of year on their given path.

          -9mm-
        • I don't think it was feasible to test at full capacity before this flight, which, as others have mentioned, is pretty well the main test flight.

          The problem is that when you have a fuel load that is designed to last 80+ hours, and weighs a LOT, you can't just take off with a full load and then land again in an hour or so. Even a lot of commercial airliners will stress their landing gear (and other "stuff") if they try to land with full tanks, never mind a ship like this that is basically a flying fuel tank

      • Re:Bit of a difference... (Score:5, Insightful)

        by worst_name_ever ( 633374 ) on Wednesday March 02, 2005 @03:32PM (#11826194)
        The Global Flyer has to be the fastest machine

        No, it just has to be faster than the last aircraft to circle the globe nonstop and unrefuelled with only a single pilot!

        • Look at how much fuel this plane must carry at takeoff. Think about what would be required to land it when fully loaded. I am sure that it could be landed fully loaded assuming that emergency measures were in place, but it is not something that could likely be done routinely IMO. I am not a pilot though nor am I an airplane engineer, so I don't know what sort of testing requirements exist in a case like this.

    • Re:Rigorous Testing? (Score:5, Insightful)

      by gr8_phk ( 621180 ) on Wednesday March 02, 2005 @03:28PM (#11826162)
      I suspect they never tested at full capacity because it might not be real safe to land with that much fuel. At 85 percent fuel by weight it'd be dangerous to land, and the handling probably isn't really great fully loaded. The only way to test with full load then would be to fly for 3 days. What's wrong with dumping the excess fuel before landing? I dunno. The web site also has a story about some problems weighing it before takeoff - not that they connect the two.

      Has he left Japan yet?

      I was pleased to read that Williams International (who made the engine) is right here in Michigan, not too far for me to work - unfortunately they had no postings for software people :-(

      • Re:Rigorous Testing? (Score:5, Insightful)

        by Rolan ( 20257 ) * on Wednesday March 02, 2005 @03:32PM (#11826203) Homepage Journal
        What's wrong with dumping the excess fuel before landing? I dunno.

        Looked at jet fuel prices lately? I wouldn't want to dump a gallon of the stuff, much less a full load.

        • Re:Rigorous Testing? (Score:4, Insightful)

          by mrchaotica ( 681592 ) on Wednesday March 02, 2005 @04:04PM (#11826511)
          It's not as if burning it is any cheaper!
      • What's wrong with dumping the excess fuel before landing?

        Jet fuel is somewhat hazardous to your health. Think along the lines of dumping gasoline on the ground. It also burns on contact with skin (as in it stings the skin like an acid, I don't mean that it burns chemically).

        The only time I have heard of anyone dumping their fuel on purpose is when they were about to make an emergency/crash landing (without landing gear cause it was stuck, or because of some other problem).
        • The only time I have heard of anyone dumping their fuel on purpose is when they were about to make an emergency/crash landing (without landing gear cause it was stuck, or because of some other problem

          Just a few years back I was flying out of O'Hare, and a the 757 I was on dumped (according to the pilot) about 85% of its fuel (and we were headed to San Fransisco, so even if they didn't have it completely filled up, you know it was a whole lotta fuel) because: one of the passengers was having some chest pa
      • And what about testing it at least by taxiing around fully fuelled? I'd expect at least that... :P
      • Has he left Japan yet?

        http://www.virginatlanticglobalflyer.com/Mission Co ntrol/Tracking/
      • What's wrong with dumping the excess fuel before landing? I dunno.

        The problem is that fully loaded the plan holds 18000 lbs of fuel. Even if they were to fly 40 hours straight and then dump the rest, you're still looking at dumping 9000lbs of fuel. That's about 3-4 tons, not exactly the most environmentally friendly thing to do not to mention the problems the locals would have with you dumping a few tons of fuel on each test flight with full tank of gass.

  • My guess... (Score:5, Funny)

    by PopeAlien ( 164869 ) on Wednesday March 02, 2005 @03:19PM (#11826067) Homepage Journal
    Aliens.

    Aliens with a thirst for fuel.

    • Re:oblig red dwarf (Score:5, Funny)

      by rob_squared ( 821479 ) <rob@rob-squared . c om> on Wednesday March 02, 2005 @03:45PM (#11826333)
      Lister: Oh god, aliens? Your explanation for anything slightly peculiar is aliens, isn't it? You lose your keys, it's aliens. A picture falls off the wall, it's aliens. That time we used up a whole bog roll in a day, you thought that was aliens as well. Rimmer: Well we didn't use it all, Lister. Who did? Lister: Rimmer, aliens used our bog roll? Rimmer: Just 'cause they're aliens doesn't mean to say they don't have to visit the little boys' room. Only they probably do something weird and alienesque, like it comes out of the top of their heads or something. Lister: Well I wouldn't like to be stuck behind one in a cinema.
    • ...fuel-hungry mynocks [starwars.com]?

  • Sky captain (Score:5, Funny)

    by notthe9 ( 800486 ) on Wednesday March 02, 2005 @03:19PM (#11826069)
    Why not just land on a flying fortess and never really stop?

  • Used the wrong units. (Score:5, Funny)

    by Anonymous Coward on Wednesday March 02, 2005 @03:21PM (#11826081)
    His plane was supposed to be loaded with 12400 hogsheads to make the 18,000 hectaire journey. Instead they used gallons.

  • Its ok., (Score:2, Funny)

    by Anonymous Coward
    We men all know cars still have half a tank even when on empty.

    • Re:Its ok., (Score:5, Funny)

      by mopslik ( 688435 ) on Wednesday March 02, 2005 @03:28PM (#11826157)

      We men all know cars still have half a tank even when on empty.

      In my car, there is no "empty". "E" stands for "enough".

      "See, honey? There's enough gas left in the tank..."

      • <obscure reference>
        "The little red needle is pointing to 'E', and while that's always stood for 'excellent' in my book, I guess it means I'm out of gas!"
        </obscure reference>

        Kudos to anyone who knows the source for that one :)
        • What is it about geeks and the firesign theatre? And how come I can remember obscure quotes like this, but not my own phone number?
    • Their fuel "empty" sensors are of the kind used for HP cartridges.

  • No pre-flight test? (Score:4, Insightful)

    by debianlinux ( 548082 ) on Wednesday March 02, 2005 @03:23PM (#11826102)
    They saw this early on. This indicates a problem that could have been found with a couple short test flights. Surely they had test flights, I mean, I wouldn't climb aboard a flying gas tank unless the thing had undergone some degree of flight testing prior to being loaded down for the long haul.

    • Re:No pre-flight test? (Score:4, Informative)

      by plover ( 150551 ) * on Wednesday March 02, 2005 @03:31PM (#11826190) Homepage Journal
      I think the problem with this live test is that the plane may not be capable of withstanding a landing fully loaded with fuel. It might be designed such that it wouldn't survive a hard impact (wings full of fuel have a lot of inertia, hit the ground hard enough and they WILL bend or fall off.)

      Think of this plane as a one-shot deal. Reusability wasn't the goal -- getting around the world was.

      Sure, pilot safety is a consideration -- in some emergency situations, the pilot could probably dump the fuel to land safely. In a worst case scenario, he could probably land with full tanks, but as I mentioned before that might not be without substantial risk to the aircraft. It might even be expected that the plane's airframe would fail if it landed full.

      • Re:No pre-flight test? (Score:5, Informative)

        by plover ( 150551 ) * on Wednesday March 02, 2005 @03:34PM (#11826220) Homepage Journal
        One other thing I failed to mention in the previous post: the fully laden wings droop substantially, and I believe they almost drag on the ground when full. It would be extremely difficult (if not impossible) to land a craft in a condition like that without accidentally dragging a wingtip.

        • Re:No pre-flight test? (Score:5, Informative)

          by omahajim ( 723760 ) on Wednesday March 02, 2005 @03:44PM (#11826323)
          the fully laden wings droop substantially, and I believe they almost drag on the ground when full.

          From my observation of the live takeoff video feed from the airport, I didn't see any drooping at all. At the end of RWY 35 where it sat a good portion of the day, the wings looked perfectly level in all shots I saw on the feed - including the moments immediately prior to takeoff. Once the takeoff roll was underway and especially once airborne, the wings appeared to have a slight bend upwards at the tips.

        • Would it really be that hard to put little rollers or teflon or something on the wingtips?
      • In a worst-case scenario, I'm going to assume that Fossett brought a parachute.
    • I doubt that the plane can land with anything close to a full tank. So, a fully loaded test flight would have been a 60 hour test flight. Doing this on a single seater without the excitement of breaking any records would probably be very dangerous.

      That's kinda the nature of breaking a world record, you cannot do a test because the test would break the record.

      Jack

  • counting on fingers (Score:5, Informative)

    by tedtimmons ( 97599 ) * on Wednesday March 02, 2005 @03:23PM (#11826105) Homepage
    That is about 380 gallons of gas, if you calculate avgas at 6.84 lbs/gallon.

    -ted

    • Re:counting on fingers (Score:4, Informative)

      by iammrjvo ( 597745 ) on Wednesday March 02, 2005 @03:31PM (#11826187) Homepage Journal

      It's a jet. It uses Jet-A, which is essentially diesel. I thought that 100LL weighed in closed to 6.0 lbs / gal, anyway.

      • Isn't Jet-A more like kerosene (or #1 fuel oil)? This [caltech.edu] PDF calls Jet-A "Aviation kerosene", as do several other pages, and shows Jet-A composition as mostly C9-C16, which matches kerosene as shown here [cdc.gov]. Diesel, or #2 fuel oil is mostly C11-C20, and is therefore heavier than kerosene and has a much higher flash point (58C vs 38C for kero). Diesel has a slighty higher energy content/unit volume that kero, too (see this [neb-one.gc.ca]).
    • how many fingers to you have??
  • Expect a go-nogo decision on going across the Pacific shortly after that ...

  • I already saw it on CNN (Score:5, Informative)

    by NeuroManson ( 214835 ) on Wednesday March 02, 2005 @03:24PM (#11826112) Homepage
    It was due to a defective fuel guage showing a full tankload, despite it being 2600 lbs short.

  • I think they are pushing it... (Score:5, Informative)

    by brienc ( 198804 ) on Wednesday March 02, 2005 @03:26PM (#11826133)
    The article mentioned they will have to decide before departing Japaneese airspace, but you can see from the current posit [globalflyer.com], they are several uhnder miles off the coast.

  • The Pilot's Creed (Score:5, Funny)

    by Spencerian ( 465343 ) on Wednesday March 02, 2005 @03:26PM (#11826138) Homepage Journal
    "Let my takeoff-to-safe landings ratio always remain at 1:1."

  • WE know where the gas went! (Score:4, Funny)

    by Anonymous Coward on Wednesday March 02, 2005 @03:26PM (#11826141)
    Damn Jawas!

  • Anyway (Score:2)

    by lanc ( 762334 )
    ...what kind of sense does it have to fly around the earth? Just to get into the Guinness recors-book? Come on. Wasting fuel, a pile of money, for one entry. pitiful.

  • Or.. (Score:3, Funny)

    by GillBates0 ( 664202 ) on Wednesday March 02, 2005 @03:28PM (#11826158) Homepage Journal
    Scaled Composites was unable to say whether it was due to leakage or evaporation

    combustion...

  • Less fuel = less weight = can go further.
  • everyone is missing the point.. its not about some millionaire breaking a record...well maybe for the millionaire it is... but doing things like this opens the doors for innovation in the feild. if this works, this will give a massive ammount of data to the aviation industry to help with fuel economy on its jets. ( and lets face it, the aviation needs all the help it can get nowadays)
    • so.. what part of the turbofan engine and the planes design is new, thereby giving new data to work with, and why does it matter if it can get around the world for the data to be worthwhile, really?

      it doesn't really open doors, it's using already opened doors and combining them to break a record.

  • they should have used the low tech fuel gage (Score:5, Informative)

    by PW2 ( 410411 ) on Wednesday March 02, 2005 @03:34PM (#11826217)
    When learning to fly a Cessna 150, my instructor always made me not trust the fuel gage since what it reports can safely be confirmed another way -- I'd have to look in the tanks and dip a stick in the fuel to be sure there was enough. When flying, it's a different story as you must trust your instruments.
    • <aol>ME TOO!</aol>

      When I was first learning to fly, I looked up the NTSB accident database for the C-152. Over and over again there were reports of mid-flight engine failures. With only one exception, every crash report had a line similar to "Total fuel found in the tanks was 1.5 gallons. Unusable fuel in a C-152 is 1.5 gallons."

      I made it my vow that I might die flying, but it was never going to be due to something that stupid- always dip your tanks.

  • I'd hate to get struck by lightning while flying that thing...

    • Re:I'd hate to... (Score:2, Insightful)

      by zeephyz ( 852835 )
      Actually, planes are pretty well protected from most lighting as you can see here: http://www.physlink.com/Education/AskExperts/ae568 .cfm [physlink.com].

      It's actually reverse lightning that causes problems, though I can't find a link talking about that right now. Basically, the reverse, or positive, lightning is much more powerful (it feeds sprites and jets in the upper atmosphere) and thus can overcome conventional protection of planes.

  • Perhaps it's better to build up to the big journey (Score:4, Funny)

    by colpitts ( 846695 ) on Wednesday March 02, 2005 @03:40PM (#11826275)
    ... start at the pole and roll it around the world in around 30 seconds. Then you could move out from there!
  • 2600 lbs, huh? sounds like a phreaking problem.

  • Steve Fossett - The Pilot (Score:4, Interesting)

    by prakslash ( 681585 ) on Wednesday March 02, 2005 @03:45PM (#11826336)

    This guy has never really been successful in any Round-The-World (RTW) flight attempts. He tried five times [stevefossett.com] to do a solo-balloon flight round the world. He failed everytime. The sixth one in July, 2002 was claimed to be a successful RTW flight but many authorities disagree because he was too far south of the equator.

    I guess, as long as he has his billions, he can continue to indulge in these quests until he succeeds - whether it is via a balloon or a jet-powered airplane.

  • Branson's Fancy Watch (Score:5, Funny)

    by SiliconEntity ( 448450 ) * on Wednesday March 02, 2005 @03:56PM (#11826448)
    The Virgin web site has an interesting story about Branson giving Fossett a fancy watch to aid him on the flight,
    Watch to the rescue [virginatla...lflyer.com]: "When speaking at a press conference the day before take-off of the emergency systems in place in the Virgin Atlantic GlobalFlyer if something were to go drastically wrong, Sir Richard Branson promptly took off his watch and gave it to his great friend Steve Fossett." But here's the rest of the story.

    According to people who were there, Richard Branson walks into the press conference holding two huge and obviously heavy suitcases when the topic came up about issues regarding the timing of the flight.

    Branson sighs, puts down the suitcases and glances at his wrist. "It's now a quarter to six," he says, and goes on to explain the planned timing for the next day's flight.

    "Hey, that's a pretty fancy watch!" exclaims Steve Fossett, the pilot.

    Branson brightens a little. "Yeah, it's not bad. Check this out" - and he shows him a time zone display not just for every time zone in the world, but for the 86 largest metropoli. He hits a few buttons and from somewhere on the watch a voice says "The time is eleven minutes to six" in a posh British accent. A few more buttons and the same voice says something in Japanese. Branson continues, "I've put in regional accents for each city". The display is unbelievably high quality and the voice is simply astounding.

    Fossett is struck dumb with admiration.

    "That's not all," says Branson. He pushes a few more buttons and a tiny but very hi-resolution map of central London appears on the display. "The flashing dot shows our location by satellite positioning," explains Branson. "View recede ten," Branson says, and the display changes to show the whole of Greater London.

    "I need this watch!" says Fossett.

    "Oh, no, it's not ready for sale yet; this is a prototype and the inventor is still working out the bugs," says Branson. "But look at this," and he proceeds to demonstrate that the watch is also a very creditable little FM radio receiver with a digital tuner, a sonar device that can measure distances up to 125 meters, a pager with thermal paper printout and most impressive of all, the capacity for voice recordings of up to 300 standard-size books," though I only have 32 of my favourites in there so far" says Sir Richard.

    "I've got to have this watch!" says Fossett. "It's just what I need for my flight!"

    "No, you don't understand; it's not ready."

    "I'll give you whatever you want for it! I'll give up my share of the royalties for the promotional tour after the flight!"

    Branson abruptly makes his decision. "OK," he says and peels off the watch, handing it to Fossett, who starts happily away, heading to the plane.

    "Hey, wait a minute," Sir Richard calls after Fossett, who turns around warily. Branson points to the two suitcases he'd been trying to lug into the press conference. "Don't forget your batteries."
  • I'd carry out my life long dream to build a popsicle stick bridge to the moon. I'd try it every so often and get the press all excited about it. Then, of course, I'd fail and then I'd blame it on some technical problem.

    That'd be great.

  • Cockpit camera (Score:5, Interesting)

    by omahajim ( 723760 ) on Wednesday March 02, 2005 @04:08PM (#11826559)
    Live cockpit camera now at http://163.205.10.109/projects/globalflyer/live.jp g [163.205.10.109]

    Previously updated about every six seconds, now I am only getting refreshes every 45-60 seconds.

  • Take-off weight (Score:3, Interesting)

    by AceyMan ( 199978 ) on Wednesday March 02, 2005 @09:04PM (#11829893)
    I won't cite specific posts, but there have been several posters who were incredulous at the idea that the plane couldn't land immediately after takoff.

    I've got big news for everyone. In 'real planes' (big twins and up) there is always a differece in Max Take-Off Weight (MTOW) and MLW (Max Landing Weight). That rights right folks: when a planes full-up, if it landed right after take-off, structural limits would be exceeded. They plane may not break catastrophically, but it would require quite a few inspection hours to be sure nothing was damaged.

    This weight delta is frequently so large (think, 4~12,000 lbs, or more) that for short hops, the plane can't take-off at MTOW -- the full burn is less than the amount required to get below MLW. In this case, MTOW cannot be achieved.

Slashdot Top Deals

He has not acquired a fortune; the fortune has acquired him. -- Bion

Close