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Air France 447: The ‘Coffin Corner’ and a ‘Mesoscale’ Maw
- TrevorJ 17y agoA very insightful examination. A lot of things I didn't know.
- anigbrowl 17y agoTrue. Too bad about the tabloid-style typography and literary style, which does serve a purpose of highlighting the takeaways but also gives it an air of sensationalism.
- dschobel 17y agoI agree, but he's pretty glib about it all (quoting star-trek? really?). Strikes me as a pretty odd tone to take.
- shizcakes 17y agoInsightful but it seems that there's a lot of speculation about this. Theres an article from timesonline that tied some pieces together and answered some questions for me (like: "How do they know this much detail of the flight without the black box?" A: ACARS). I hope this is helpful to someone else: http://www.timesonline.co.uk/tol/news/world/us_and_americas/article6446268.ece http://www.timesonline.co.uk/tol/news/world/us_and_americas/...
- samlittlewood 17y agoThanks. I assume that the forum mentioned in the article is http://www.pprune.org http://www.pprune.org. The current thread about this accident is http://www.pprune.org/rumours-news/376433-af447.html http://www.pprune.org/rumours-news/376433-af447.html Apart from the current tragedy, it's a great window into another professional sphere.
- mhb 17y agoQ: ACARS? A: automatic communications and reporting system
- telma 17y agoThe weather was never considered "horrible" and still isn't. [edit:] At least 12 planes took the same route that night without any incident. http://ibnlive.in.com/news/12-planes-shared-sky-with-af-447-reported-no-trouble/94293-2.html http://ibnlive.in.com/news/12-planes-shared-sky-with-af-447-...
- joshwa 17y agoFrom the very last paragraph of the same article (which originates from CNN, incidentally): > Although none of the other flights are known to have reported weather problems en route, aviation experts said weather can change suddenly and vary over short distances, so one plane might experience conditions far worse than another.
- run4yourlives 17y agoReports seem to indicate that they almost made it through the stormcell. Very unfortunate. Whatever it was probably happened extremely fast. Perhaps a (ridiculously unlikely) wing snapped off? Or they stalled and spinned violently?
- stcredzero 17y agoBoeing tests its wings to breaking by bending them behind the back of the plane until they are pointed up at ridiculous angles. The kind of force that would break the wings of a modern jetliner would also break the necks of a large number of the passengers. http://www.youtube.com/watch?v=pe9PVaFGl3o http://www.youtube.com/watch?v=pe9PVaFGl3o EDIT: I stand corrected. As pointed out below, that huge deflection doesn't represent neck-breaking forces. But imagining the force of an updraft that can accelerate an airliner upwards at 2G's -- that's still a heck of a lot of power.
- DocSavage 17y agoCool video. I wonder how much of an engineering/structural difference there is between the heavier 777 and the Airbus A330-200 that crashed.
- yhnbgty 17y agoBoth are tested to 150% of their maximum rated load.
- davepage 17y agoNot at all. The A340 limit load factor is something like +2.5 / -1.0g. This is not a condition injurious to seated passengers. It is unrestrained passengers who are injured in turbulence -- but that is due to the passenger/cabin collision, not the initial acceleration. The wings in the video flex a long way under these relatively light load factors because the wings are designed to be only a little bit stronger than they need to be. Aerobatic airplanes and pilots routinely experience transients to +/-6g with no ill effects.
- TweedHeads 17y agoI will always say it was a bomb, and the more they try to make it look like it wasn't, the more I believe they are just trying to hide it from the public not to scare them to fly like in 2001. It was a bomb.
- TweedHeads 17y agoFor a hundred years we've been flying planes thru storms, lightnings, adverse conditions of every kind, so fuck the coffin corner. The pilot and copilots had thousands of flight hours under their belt. Not a single mayday call.
- nopassrecover 17y agoRadio communication fail? Weird electrical/magnetic phenomena? Meteor? These are just some of the more plausible ideas than "covert terrorism".
- hunterjrj 17y agoWhy has no one stepped forward to take credit for downing the plane with a bomb? Isn't that the MO for terrorist organizations? Accidents happen, unfortunately. Sometimes planes crash. Our technology isn't perfect, and all we can hope for now are useful lessons to be learned from the crash itself.
- TweedHeads 17y agoIf I was a terrorist org, I wouldn't take credit. The new modus operandi is stealth mode, the days of TV shows about terror are over. Terror to create havoc on the world economy and air traveling will be the first hit. Expect more "accidents" in the future.
- transburgh 17y agoif a terrorist group does not claim it, the world would not know it was a bomb (per your assumption) and that fear would not translate to the population....therefore your theory dies
- biohacker42 17y agoSo while you are napping, eating or watching a movie on that flight to LAX, you should know the plane you are flying is cruising along at the ratty edge of its capabilities. Why? Money. The higher an airliner flies, the better gas mileage it gets. As libertarian I prefer an airline which will charge me premium for flying more expensive but safer routes. However, as a realist I realize that the barrier to entry for airlines is very high and competition is sub-optimal. So I'd settle for a government mandate of how high commercial airlines can fly.
- frisco 17y agoThat's a bit of a jump. How'd you go from "As a libertarian..." to "So I'd settle for a government mandate" in 3 lines?
- staunch 17y agoHe's that smart.
- Retric 17y agoHowever, as a realist... I would assume HN would favor people who looked beyond knee jerk responces. Just because you like to use the free market when it's possible does not mean you need to apply it in all cases.
- biohacker42 17y agoWell simple. I really do want the market to work, but I know in reality it very often does not work at all. Most often with big industries where the startup costs are high. Do you prefer to continue to fly in a needle's eye rather then have the government step in? Ideally at least one airline would offer the safer option as a way to gain customers, but what if no one does? Is your libertarianism that pure? If so, that's admirable, I guess my ideals are just not quite as strong.
- anigbrowl 17y agoSeems like a rather suicidal market strategy. So you invite people to pay 2x to fly with FlySafe (perhaps an existing airline with n outstanding safety record that rebrands itself), milk the resulting controversy to sell tickets for a while, only to later have every untoward incident, no matter how trivial, spun into a damning indictment of your business philosophy? No thanks. Furthermore, the first time such a company did have a fatal or obviously dangerous incident, they'd go insolvent immediately. I see the point you're trying to make but it's simply impractical in a mass market like commodity air travel. Uber-expensive executive flying, perhaps.
- tomiles 17y agoWhy when internet is becoming available in planes is something as simple and and essential as updated weather reports not possible during a flight? Why are these practices seemingly stuck in a stone age of paper weather reports, printed before the flight leaves, that could have been outdated even before the planes takes off. Maybe this accident will speed up a much needed needed technological update in this aspect of air-travel. We should stop wasting dollars on security theater measures and invest it in real safety measures that can save lives.
- JimmyL 17y agoThey get weather updates en-route sent to them by their home airline (via the radio system) - not to mention that jets of that size carry along with them a better weather radar system than most local news channels have.
- tomiles 17y agoI'm talking about satellite imagery like it is shown in the article, which is the only kind that would provide reliable and usable info for storm evasion. You need a view from above to see a storm size and not just a surface look at it from the sides (with a radar). Weather radar only provides limited information, like the article says. "interpreting its display is a bit of a black art." - "It is akin to a blind man with a cane;" - "For instance, the radar mostly detects rain and hail – and if that first layer of storm cells was particularly heavy, it might have acted like a curtain – hiding the reinforcements from radar beams." You can't know what's inside a walled garden or know how big it is just by looking at one side of the outside walls, you need something that allows a top view.
- dpifke 17y agoMore raw data to the cockpit is unlikely to help. Pilots have a lot of things going on and varying levels of weather knowledge and experience (even professional pilots - weather is but one thing you train on). A professional meteorologist on the ground who can interpret and summarize the relevant information is of way more use.
- grandalf 17y agoThe article suggests that a stall is a horrible outcome. Old style biplanes used to do "stall landings" all the time. If you know the characteristics of the wing, then a stall can be anticipated and is not necessarily cause for alarm. How is it that the autopilot system (or other systems on the plane) would not be programmed to handle a stall gracefully? In a stall the wing loses lift, but as the plane falls the air thickens and the angle of attack decreases and the wing ought to regain lift sufficient for the pilot to be able to control the plane. I'm not suggesting that handling a huge jet in a stall would be easy, but I would guess that knowing how to do it is part of the requirements for flying one.
- lutorm 17y agoThis was my question too. But I think stalls in large airliners are a very different thing than in GA aircraft. I'm pretty sure full stalls are still part of the test regimen, but I don't think normal pilots ever do a full stall. It may also be other factors playing in at high altitude, and of course in severe turbulence a recovery might be even more difficult.
- marvin 17y agoGlider pilot here. I have decent knowledge of aerodynamics, but have never studied large jets in detail. This is my personal theory - essentially what lies behind the words of a few articles I have read over the last few days, but the authors haven't been able to formulate it clearly. Assuming that the autopilot and fly-by-wire systems were somehow compromized, a full stall in the "Coffin Corner" (Q-corner) would be a very, very serious condition. A stall causes the nose to drop and speed to accumulate. Since the difference between the stalling speed and the never-exceed speed is so small at the altitude in question, this accumulation of speed could easily cause the plane to exceed its critical Mach number, causing supersonic shockwaves around certain parts of the airfoil. In planes not designed for supersonic flight, these shockwaves will eventually cripple the effect of the control surfaces. If the plane is in a nose-down position when it looses effect on its elevator rudder, the plane will overspeed and eventually suffer structural failure (essentially meaning the loss of some critical part) due to flutter (resonance in parts of the airframe) or aerodynamic stresses. A stall during normal flight conditions doesn't have to be a serious problem, but these weren't normal flight conditions. And the information that we have suggests that certain Airbus models have had problems with their pitot (speed measurement) systems in icing conditions, leading to erroneous speed readouts. The fly-by-wire system, which prevents the pilot from flying the aircraft into stall or overspeed, cannot function correctly without a correct speed measurement. And as I have detailed, a proper stall might be enough to doom the airplane.
- DanielBMarkham 17y agoMiles is a pilot and aviation enthusiast, and I've admired his work in the past. I hope this bit of writing is more public-serving than self-serving. After all, we still know very, very little about what happened, aside from the data transmissions. Even speculating on structural disintegration is problematic because the obvious next question was: why wasn't the plane configured for heavy turbulence? So you're left with this article that goes over some cool new facts (for those of you outside the aviation community) but really doesn't shed much light on the incident at all. It's not a news piece, it's not an opinion piece. It's kind of a science piece hanging off a news story -- one that puts the author in the role of expert without facts and one in which hundreds of people get killed. Not my cup of tea.
- noonespecial 17y agoI know its all very serious and its sad commentary on the mental baggage I now carry from watching too much TV when I was 15, but I couldn't help but do a double take when a guy named "Miles O'Brien", quoted Scottie describing engines.
- chipmunkninja 17y agoWhile there is a lot of good information in this article, the tone is a bit too tabloid-sensationalist for my tastes. "So while you are napping, eating or watching a movie on that flight to LAX, you should know the plane you are flying is cruising along at the ratty edge of its capabilities. Why? Money. The higher an airliner flies, the better gas mileage it gets." Boo those big corporations for trying to pick optimal flight paths, save customers flight time, or otherwise make a buck (and who cares about all the environmentalists breathing down their necks about burning so much kerosene). How DARE they? Think of the children!! The one thing common after all these crashes is the amount of looney speculation that goes on right after, and then we magically forget about it. Does anybody even remember the British Airways 777 from Beijing that landed short at Heathrow a couple of years back? The reason: entirely mundane - faulty fuel pump.