Air France A340 crashes in Toronto

Discussion in 'TM Lounge' started by FlugelFlyer, Aug 2, 2005.

  1. FlugelFlyer

    FlugelFlyer Piano User

    311
    1
    Dec 15, 2003
    Palos Park, IL
    http://news.yahoo.com/s/ap/20050802/ap_on_re_ca/canada_plane_crash


    From unconfirmed reports elsewhere, I'm going to guess that thankfully a great majority of the passengers survived, though I'm not completely optomistic yet. From what I gather, plane landed in bad thunderstorm, struck by lightning, lost all braking and engine power, overran runway, plunged into ravine, and split apart.

    I believe the explosion may have occured a few minutes after it came to rest, presumably from the O2 tanks igniting. Either way, I'm hoping that most if not all of the passengers survived. The pilot and copilot are confirmed alive and well, so that'll help the investigation afterwards.


    [edit:] confirmed now that all passengers and crew survived; that's extremely good news given the extreme circumstances.
     
  2. Tootsall

    Tootsall Fortissimo User

    4,529
    8
    Oct 25, 2003
    Yee HAW!
    I've just finished watching multiple TV channels about this incident. So as the plane touched down, something happened and the plane skidded off the end of the runway. Most logical speculation involves either simultaneous lightning strike or hydroplaning.

    One passenger reported that there were lightning flashes as the plane landed. Another reported that they felt it touch down and they broke into applause (he said that they'd been circling for some time). But immediately after that there was a series of bangs or bumps. That suggests hydroplaning or multiple explosions. The investigation will show which; the rear of the plane broke off and caught fire and one wing apparently broke loose.

    The media is complaining that the airport authority left a fairly deep ravine only 200 yards from the end of the runway. Well, the ravine was there before the runway was installed (or... more likely... lengthened). And a dang good thing it was there... it kept the plane from skidding onto or across the country's busiest highway at it's busiest spot! If you saw the coverage you saw the traffic going past the site.

    Maybe airports should consider having "gravel traps" (if you've seen any car racing or driven through mountainous country and seen "runaway lanes" you know what I mean). Time will tell.

    Everyone got off "in one piece"... that's a miracle. Apparently most of the injuries occurred by the emergency deplaning of passengers and consist of "soft tissue" damage.. sprains and wrenches and maybe a broken ankle or two.

    Now... here comes the rant. You may wish to put your children in a different room for a moment.

    The FREAKING NEWS MEDIA! As I watched I got more and more impatient with these highly paid clowns asking the same questions over and over of the various "authorities" who haven't even had time to phone their wives to say that they'll be "late for dinner"! Then, to top it all off, I switched to CNN to see what the foreign media had to say. There was the lovely Paula Zahn making the statement that witnesses reported that "THE WIND WAS SO STRONG THAT THE TREES WERE PERPENDICULAR TO THE GROUND!" Now, JUST HOW THE HE!! DO TREES GROW IN ATLANTA?... HORIZONTAL? Can't this "media star" even get her directions right? Is she so wound up with trying to "sell" her story (and herself as the star of the story) that she can't remember which way trees grow in Canada!?

    Well, I'm not going to turn on FOX, they'll probably be speculating that it was due to Canada being a haven for terrorists!

    Whew.... sorry about that but I needed to get it out of my system.

    In the meantime, let's be VERY thankful that everyone walked away.
     
  3. sublmbadfish

    sublmbadfish Pianissimo User

    75
    1
    Jul 9, 2004
    San Francisco, CA
    My youth orchestra was coming home from toronto today and the second flight is still stuck there...
     
  4. bigaggietrumpet

    bigaggietrumpet Mezzo Forte User

    801
    1
    Jan 23, 2004
    Nazareth, PA
    The problem that I see with your gravel trap idea, Toots, is that when the wheels hit it, they're supposed to sink, miring the wheel, increasing friction, and slowing the plane down, no? Unfortunately, landing gear, while sturdy when it comes to cushioning a vertical component of force, don't do so well when a sudden horizontal force is applied. They'd mostly likely shear, increasing the chance of explosion.

    And yes, the media these days is just absolutely ridiculous.
     
  5. Tootsall

    Tootsall Fortissimo User

    4,529
    8
    Oct 25, 2003
    Yee HAW!
    I know that the gear is liable to shear off.... as it undoubtedly did when Air France "hit the ditch" (with one passenger reporting that the wing and engine "hit the ground" there is a consideration that the gear collapsed before the plane went off the end...as it possibly could if it had been hit by a downburst at or around the moment of initial touch down). However, the forces involved in severe braking are also unquestionably quite high and the goal is to bring it to a stop as safely as possible: there aren't that many airports near major urban regions with unlimited run-off room!

    Look at it as a design problem: as one of my old engineering professors would have said "let us begin by defining the real problem". The problem is....for whatever other events that may have already occurred, we now need to bring a "runaway" aircraft which cannot get back into the air to a stop as safely as possible and with a minimum of damage to surrounding structures or persons. The only answer is to put something in it's path that will (as gently but firmly as possible) slow it down and bring it to a halt in an upright position. The military use catch nets....impractical for civil aviation and probably of limited use given the size and weights of these large planes. A gravel trap is one answer (possibly of limited use with heavy snow-cover and/or freezing temperatures); a "thicket" of trees is another (don't let them get too big though or you'll have a replay of that civil aviation film of them using telephone poles to slice the wings and allow the fuel tanks to burst open!) I think on balance that I'd rather rely on the gravel traps!

    Ok, we can also refine the original problem definition to include "aircraft with from one to 300 passengers and weighing from 1,000 lb up to 100,000 lb and travelling at speeds of from 20 to 200 mph"! Quite a challenge, no? Accepting the limitations of the strength of the landing gear, I've seen those gravel traps "haul down" everything from F1 racers (at 1,400 lb?) to 80,000 lb semis! They do work. And I'd sure as heck rather end up in a belly slide than smokin' through an industrial park or residential area... or, (as in this case), possibly down a multi-lane highway at rush hour!
     
  6. bigaggietrumpet

    bigaggietrumpet Mezzo Forte User

    801
    1
    Jan 23, 2004
    Nazareth, PA
    The gravel idea is making more sense now that I think about it, though I don't think that it's a universal solution. If the gear sheared, the plane would land onto its belly (hopefully) and the force due to friction would increase. The only question is whether or not it would increase enough to overcome the overall momentum of the plane (there's a LOT of momentum there. Plus you have to deal with the nose gear shearing first, thus plummeting the plane nose first into the ground (pilots would really give you grief here).

    What about a catapault system similar to that used on carriers? Naturally, the hydraulic rams would have to be several times bigger (haven't taken fluid dynamics yet, so I can't really say how much bigger). If you placed the trip wire at a position where the plane could travel another 150, with the wire catching on the rear wheels, would that work? You would have to design, of course, a catcher (hook). What if you had Boeing and Airbus design retrofits to existing aircraft some kind of hook in that fashion? I realize that it would be very difficult to pull off, but when you think about the cost of a plane running head on into a highway or building, it seems cheaper. And I'm sure the FAA has come up with dumber rules before.
     
  7. FlugelFlyer

    FlugelFlyer Piano User

    311
    1
    Dec 15, 2003
    Palos Park, IL
    I think for starters, the investigators will have to figure out why aircraft power wasn't shielded from a lightning strike. Jetliners themselves have incredible braking power when compared to small piston aircraft or even cars. To put it in perspective, I land a Cessna 172 at about 60 kts and roll off fairly easily after 1200', and that's approximately an 1,800 lb aircraft when loaded normally. A 737 that sits at the same airport I'm based out of landed with about 80,000 lbs of weight, give or take (it was fully empty), and easily rolled off after about 3600'. Imagine that, an aircraft 40x heavier than mine rolling off in only 3x the distance. That's an STOL aircraft compared to any Cessna when you think about it.

    Also though, for those who've flown out of DFW, landings and takeoffs are traditionally to the south, and I'm not completely sure of the layout of the airport, but I believe there's about two miles of pure fields after the runway. If an A340 runs off after 13,000' in a good ol' Texas lightning storm, it has a much better chance of coming to rest on flatlands.

    Just a couple more things to consider.
     
  8. FlugelFlyer

    FlugelFlyer Piano User

    311
    1
    Dec 15, 2003
    Palos Park, IL

    One more thing just to run off to the forum, I believe most if not all jetliners are designed to land on their engines in a worst case scenario. I believe there are a couple of aircraft out there with pads on the bottoms of the nacelles, and if one makes an engine landing, the pads are the only things that need to be replaced (bar engine damage)! Jetliners sure may seem fragile, but in truth they're almost built like tanks. I should see if I can find the max braking demonstration of the 777-200 during testing. I forget the details, but I'll see if I can pull them up.
     
  9. Tootsall

    Tootsall Fortissimo User

    4,529
    8
    Oct 25, 2003
    Yee HAW!
    I wish I had a copy of the high speed films we used to take at Pratt & Whitney (United Technologies) when doing ice tests on fan jets. We'd fire golf-ball sized ice "pellets" straight into the front of a running (ground/static mounted) jet engine (Think Cessna Citation biz-jet here). Titanium fan blades would wave like stalks of wheat in the wind! I don't even want to describe the mess of chucking a dead bird in!!!!!

    Flugelflyer is right... planes are built like tanks in virtually all respects. The real problem is the incredible amount of momentum that the entire "mass" has at the velocity it is travelling and the need for light weight to maximize economy (profits) to the operators.

    (Yes, I was a gas turbine designer in a previous life... got bored with aerospace though...too many regulations).

    Edit: So far there is no "real" evidence that's been presented other than a couple of passengers who reported that the "lights went out" at or near the moment of touchdown and some terminal employees who claim to have seen a lighting strike directly on the top of the plane at that same time. Another passenger reported that he "saw" the engine touch down on the ground shortly after landing....landing gear failure?. Someone else has suggested tire failure... usually indicative of a very hard landing.... downdraft? So it goes... the pros will do their work and the entire story will come out eventually. After all... they've got 309 witnesses this time!

    Edit #2: Flugel, your comments about DFW are right on. Flat, open fields are the BEST insurance. Unfortunately not every airport has 2 miles of fields! Things would get very sticky at Newark and Ohare.... Logan has a bit of a "water problem" (as does Vancouver & San Fran.). Calgary isn't too bad (yet!... the city is building out like mad). Montreal.... depends if you're going through Dorval or "Miserabel". A runout at Halifax and you end up in the trees (as a couple of Air Canadas have done).

    Looking at the satellite map (maps.google.com) and you'll see very quickly how bloody CLOSE 24L is to the 401 highway... it's almost like it's just "another lane"! If a landing plane gets blown slightly off course or veers after touchdown there is going to be one heck of a mess. They "had horseshoes where the sun doesn't shine" this time.
     
  10. FlugelFlyer

    FlugelFlyer Piano User

    311
    1
    Dec 15, 2003
    Palos Park, IL
    O'Hare? No space? Bah humbug dude, you ain't never been in Alaska. :lol:


    Here's "no space", Alaska 737-200's land here about once a day: http://www.airnav.com/airport/PADU


    I hear the missed approach procedure is tricky also as you're flying directly around a mountain. :shock:


    I hear you though on the regulations Toots. Even as a humble ol' Cessna driver, there's a helluvalota rules you could get busted on if the FAA decides to run a spot check on your aircraft and papers. I forget the specific clause in the law, but the FAA is a civil, not "legal" per say branch of the government; thus, they can run a "search without suspicion" on you as long as it's not specifically for marijuana or legal matters like that.
     

Share This Page