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Could a Meteor Have Brought Down Air France 447?
niktemadur writes "In light of an Air Comet pilot's report to Air France, Airbus, and the Spanish civil aviation authority that, during a Monday flight from Lima to Lisbon, 'Suddenly, we saw in the distance a strong and intense flash of white light, which followed a descending and vertical trajectory and which broke up in six seconds,' the Cosmic Variance blog team on the Discover Magazine website muses on the question 'What is the probability that, for all flights in history, one or more could have been downed by a meteor?' Taking into account total flight hours and the rate of meteoric activity with the requisite mass to impact on Earth (approximately 3,000 a day), some quick math suggests there may be one in twenty odds of a plane being brought down in the period from 1989 to 2009. Intriguingly, in the aftermath of TWA flight 800's crash in 1996, the New York Times published a letter by Columbia professors Charles Hailey (physics) and David Helfand (astronomy), in which they stated the odds of a meteor-airplane collision for aviation history up to that point: one in ten."
The BBC has a better explanation in their article about Airbus reissuing guidelines on what to do when speed detectors give differing results, how this may happen and why it could have caused the crash. From the article: "Meteorologists say that the Air France Flight 447 had entered an unusual storm with 100mph (160km/h) updrafts that sucked water up from the ocean. As the moisture reached the plane's high altitude it quickly froze in -40C temperatures (thus freezing the airspeed detectors). The updrafts would also have created dangerous turbulence, they say. More info here.
I enjoy flying simply because the idea is so absurd. I often try to imagine what it would be like to show someone from the 1700s or so around the world as it is today and modern flight is one of the more ridiculous things - you have these massive hunks of metal held in the air by the air itself that carry people at high speeds and high altitudes all over the world. In flying, I feel I have experienced something amazing the human race has achieved. Car travel, by contrast, is largely mundane.
The thing to remember is that statistics speak to populations, not individuals. As you noted, the odds of an accident for a typical driver may be X, but if you drive safely, or very rarely, or only in optimal conditions, etc., then your personal risk will be less than X.
It should also be remembered, though, that people tend to underestimate the extent to which they match the statistics. Like that Garrison Keillor joke about Lake Wobegone, "where all the children are above average." I think I read once (no citation, sorry) that something like 80% of drivers believe they're above average in driving skill. They can't all be right!
Some pilots on PPRuNe suggested that it is very unlikely to find any hail of significant size at FL350 (35,000 feet), and that if you find any at all, it was blown up there from a lower altitude (i.e. relatively low speed). Besides, there's no reason to believe a hail ding is going to bring down something the size of an A330.... That said, anything is possible, I suppose, particularly given the amount of composite material involved.
Check out my sci-fi/humor trilogy at PatriotsBooks.
That's interesting.
I don't want to knock air travel, which is truly remarkable, but on a holiday weekend, when a highway is at capacity, but not over, and dusk is upon me, the sight of thousands of cars traveling together at 70+ MPH truly amazes me.
The fact that I can, at a moments notice, simply travel hundreds of miles (days or even weeks of travel historically), with hundreds of pounds of stuff, do something and travel back, all in a weekend is quite marvelous.
And I would never fly anywhere in that short of a period willingly (yuck!), though I did it once pre-911.
Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg
Super, now all the insurance company should need to do is establish that God exists.
And if they can do that, then isn't the entire Universe an Act of God?
What do we pay insurance for, then?
You see? You see? Your stupid minds! Stupid! Stupid!
You may not be able to move your whole body that fast, but you can get parts up to that speed. It's not too hard to throw a small object at highway speed, so being able to react to someone else doing it could be quite useful. Same idea applies to a punch or kick.
If it's not on fire, it's a software problem.
the trouble comes when people don't keep a large enough margin of safety and something breaks the general rules that allow you to treat the situation that way.
The trouble comes when the real world intersects with your imaginary situation. At 60 mph there's four times the potential force acting on your tires than at 30 mph, and the interface between road and rubber changes dramatically — to say nothing of the rubber itself! The same is true of every other little bit of your car, except that some of those relationships produce a multiplication and/or reduction of force, such as the lever arms in your suspension. The behavior of the bushings, springs, and shock absorbers is wildly different when you hit a bump at 30 mph than when you hit it at 60 mph.
If you're not thinking about what each tire is going to do at your given speed when you press a pedal or turn the wheel, you're not driving. You're chairing a committee.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
This is also why there is such a huge push against automated driving
The push against automated driving was initiated by the car companies, it was called buying up rail, bus, and streetcar lines, mismanaging them to drive users away, then terminating them when it could be justified by lack of profit.
There's one right way to do automated driving, it's called rails. Roads are stupid, wasteful, and unnecessary. They are inefficient to produce and to maintain. Their only advantage is that tanks can still drive on them when they've been bombed full of holes and if we're going to stick to a military mentality forever, someone please let me know how to get off this fucking planet without cutting off my nuts and eating the pudding.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
However, a person of the 18th century wouldn't have any context in which to evaluate the relative planet-shrinking abilities of cars vs. planes. Ballpark it at 500 miles per day for a car vs. 10,000 miles per day for a plane. To a Parisian commoner of that era, that's a matter of being able to travel to Turin vs. Tokyo, both of which are just names of far away places to him, if he's even heard of them.
For comparative purposes, imagine that somebody from the future were to show a modern Earthican two forms of space travel - one that could take you to Polaris (430 light years) in a day, and one that could take you to the Orion Nebula (1,500 ly). Sure, if you know the distances it's obvious that one's faster than the other, but what does that mean to you? Both are so far from anything you know, and so far beyond any distance that you ever imagined travelling, that the difference is meaningless to you.
I disagree. A fast horse on good terrain could make 100 miles per day. A car is just like a somewhat faster horse. A plane, not requiring roads and able to travel anywhere on the planet in a day is a several order of magnitude increase.
Man, you really need that seminar!
Over 100 incidents in 9 years.. and how many auto incidents in the hour since you posted ? .. how many bus or train incidents in the same 9 years ? .. how many flights takeoff and land at your nearest airport each day ? .. What is interesting, is that I have asked people who won't fly because they fear crashing, if they are afraid of planes falling on them.. no one ever said they were, but there are probably more planes flying over most people per year than flights taken by them.
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UPS uses this system on all their planes, not only for air safety but also for tracking.
http://en.wikipedia.org/wiki/ADS-B
Pilots and air traffic control love the system, it allows them to see visually where everyone is located/speed/atlitude/GPS and all broadcasting is done from the plane to ground based radar.
Doesn't take much bandwidth at all, as they can use the VHF channel, 978 MHz UAT and another mode.