• AirAsia crash victims found
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[QUOTE=Big Dumb American;46822380]A tailwind physically pushes the plane forward. It is actually preferred to fly with a strong tailwind, because it saves on fuel costs and boosts your travel speed. Take off and land in a headwind for a quicker and shorter takeoff and landing, and travel with a tailwind if possible. Source: I'm a pilot.[/QUOTE] This explains quite a lot. If it is common practice to fly with a tailwind, then I could imagine every plane-based company to recommend using them under normal conditions. After all, it is efficient and fast. But then say you happen to fly into a strong storm where the tailwind goes much faster than your current flight speed and overpowers it. It would be logical to assume the plane would accelerate forward, but also decline in altitude, right?
[QUOTE=Leintharien;46822456]This explains quite a lot. If it is common practice to fly with a tailwind, then I could imagine every plane-based company to recommend using them under normal conditions. After all, it is efficient and fast. [b]But then say you happen to fly into a strong storm where the tailwind goes much faster than your current flight speed and overpowers it.[/b] It would be logical to assume the plane would accelerate forward, but also decline in altitude, right?[/QUOTE] I don't think we live on Saturn m8
[QUOTE=Leintharien;46822456]This explains quite a lot. If it is common practice to fly with a tailwind, then I could imagine every plane-based company to recommend using them under normal conditions. After all, it is efficient and fast. But then say you happen to fly into a strong storm where the tailwind goes much faster than your current flight speed and overpowers it. It would be logical to assume the plane would accelerate forward, but also decline in altitude, right?[/QUOTE] This is fucking with my head a lot more than I care to admit, so I'll just say that if we are seeing winds faster than commercial jetliners on planet Earth, we've got a hell a lot more to worry about than our transportation needs. Generally speaking, tailwinds are never a problem, unless you happen to be landing or taking off with one, as they can dramatically increase your landing/takeoff distance and make you run out of runway. The most annoying and dangerous kind of wind is one coming at an angle to your destination or your runway, because you have to orient your aircraft against it. Think of your aircraft as swimming through the sky, and the wind like currents. You'll travel in a straight line, relative to the ground, but if you are pulling yourself through a strong current that is trying to push you off course, you'll have to swim sideways. You can see videos of it in action, with a plane coming in for a landing at a really weird angle, just to straighten up at the last second before touching down, so the wheels don't get all jacked up. All of this is just to say: a strong tailwind did not cause this aircraft to crash.
[QUOTE=Big Dumb American;46822629] The most annoying and dangerous kind of wind is one coming at an angle to your destination or your runway, because you have to orient your aircraft against it. Think of your aircraft as swimming through the sky, and the wind like currents. You'll travel in a straight line, relative to the ground, but if you are pulling yourself through a strong current that is trying to push you off course, you'll have to swim sideways. You can see videos of it in action, with a plane coming in for a landing at a really weird angle, just to straighten up at the last second before touching down, so the wheels don't get all jacked up. [/QUOTE] Slightly off topic but go on YouTube and search for "Crosswind Landing Difficulties ". Its one of the best 'genre' in YouTube for me, really mesmerising and it's amazing thinking how the pilots have to be trained to negotiate such conditions.
[QUOTE=oakman26;46822648]why would a plane descend with a tailwind, what force is there making the plane descend? [editline]30th December 2014[/editline] ????[/QUOTE] I'm beginning to think you people are assuming I'm misusing a term here. When I say air speed, I am literally meaning Indicated / True Air Speed, as in not the speed relative to the ground, but the speed of which the air travels over the wing. The same wing that provides lift. If wind were to push in the opposite direction of the wing to the point that air does not travel over the wing, then the wing will not provide lift, and will therefore fall out of the sky. But as Headhumpy and Big Dumb American have explained to me, the conditions required for such a circumstance are unrealistic with our current environment.
Ye, airspeed and ground speed are very different. Remember that your plane is pulling itself through the air, but the air is also moving over the ground. It is possible to have zero, or even negative, groundspeed (the rate at which your aircraft moves over the ground) while still traveling through the air (airspeed). I've done it a couple of times during training. In a light enough aircraft with a low enough stall speed, you can face into a strong winds, lower your flaps and raise the nose (maximizing lift), and reduce your airspeed to the minimum limit and actually hover in place, or even move backwards, relative to the ground.
I have no idea if a tailwind could be strong enough to stop a 737 generating enough lift to maintain altitude, but theoretically a tailwind [i]could[/i] do that as there'll be a certain air speed over the wing required to generate enough lift. I find it way more likely there was some sort of malfunction, though.
[QUOTE=chaz13;46822835]I have no idea if a tailwind could be strong enough to stop a 737 generating enough lift to maintain altitude, but theoretically a tailwind [i]could[/i] do that as there'll be a certain air speed over the wing required to generate enough lift. I find it way more likely there was some sort of malfunction, though.[/QUOTE] You're right, with a strong enough wind it is 100% possible. However it is not likely on Earth, even in a Hurricane. I believe it is most likely an airspeed indicator error, causing a stall and crash. Plus, they were near bad weather, so if they ended up in it with visibility near 0, that's a good recipe for an air disaster episode. Hopefully it wasn't a pitot tube issue like the Air France crash. That would make this situation even worse knowing this kind of thing has happened before and happened again. With that said, with most crashes like this we won't know until an official report comes out. For all we know a screw stripped in the elevators and caused an uncontrollable dive and the weather had nothing to do with it.
[QUOTE=chaz13;46822835]I have no idea if a tailwind could be strong enough to stop a 737 generating enough lift to maintain altitude, but theoretically a tailwind [i]could[/i] do that as there'll be a certain air speed over the wing required to generate enough lift. I find it way more likely there was some sort of malfunction, though.[/QUOTE] You have to remember that the air pushes the plane as well - a sudden gust of tailwind could temporarily reduce lift, but if it was sustained would quickly speed up the plane and resume normal (albeit with a higher groundspeed) flight.
Would you have better chances at surviving if the plane fell over flat land in Germany for example?
Great someone left tape over the pitot tubes... :rolleyes:
[QUOTE=oakman26;46823222] - wall of text - [/QUOTE] Holy fuck, bud. I was just trying to incite some interesting discussion. You don't have to pick apart everything I said and analyze it in a lab. If you give me a couple minutes I'll read what you said and I'll try to figure out what to do. [highlight](User was banned for this post ("Why reply?" - SteveUK))[/highlight]
You're mostly correct, but I want to address this: [QUOTE]The point you want to raise is what happens if the plane is going IAS of zero in a wind, and the plane has a positive ground speed. Say a plane is flying at IAS of 150 knots which is above it's stall of 100 knots. If that plane suddenly encounters a tailwind of 500 knots, it's IAS is still 150 knots, there is no reason for it to suddenly decelerate relative to the air around it, tailwind or not. As long as the plane is moving relative to the air around it, it flies.[/QUOTE] IAS can and will fluctuate in fluctuating wind. If the aircraft is flying in tranquil air and then encounters a tailwind, its IAS will drop slightly (depending on the strength of the tailwind) because of the inertia of the aircraft. That being said, the IAS should recover as the aircraft continues to accelerate. The aircraft propels itself inside the mass of air. It isn't solely subject to outside conditions. What's important to remember is that the 737 has a cruising speed of around 480 kt. It's simply not feasible for a burst of wind to have brought it down.
[QUOTE=Leintharien;46822456]This explains quite a lot. If it is common practice to fly with a tailwind, then I could imagine every plane-based company to recommend using them under normal conditions. After all, it is efficient and fast. But then say you happen to fly into a strong storm where the tailwind goes much faster than your current flight speed and overpowers it. It would be logical to assume the plane would accelerate forward, but also decline in altitude, right?[/QUOTE] Can you please stop posting? [editline]30th December 2014[/editline] [QUOTE=Leintharien;46823292]Holy fuck, bud. I was just trying to incite some interesting discussion. You don't have to pick apart everything I said and analyze it in a lab. If you give me a couple minutes I'll read what you said and I'll try to figure out what to do.[/QUOTE] Every single one of your posts in this thread has been dumbass conjecture from a completely ignorant point of view.
Okay so let's see how much I can clarify here: [quote]-First of all you say that with enough headwind, you can takeoff while being stationary, this is true. -Then you say that you can't launch a plane off a treadmill, but didn't you just say that you can take off while stationary with a headwind???[/quote] The point of me mentioning the plane-on-treadmill example was to illustrate the difference between ground air speed and IAS. Bear in mind that at the time of me bringing up that example, I was unsure of how well everyone understood flight, so I tried to use what I thought was a simple example. It seems, however, that it was a poor choice. [quote]"plane-based company"- airline.[/quote] Yeah that's the word I was looking for. I admit I look like a bit of a cock calling it like that, but for the life of me I couldn't remember the name and I was too lazy to look it up. [quote]500km/h[/quote] Even I'm getting tangled up in what I was originally meaning for that argument so I'm just going to leave it alone. [quote]IAS[/quote] Although I understood the concept, I was unsure to which term was more accurate so I had looked it up before using it. Unfortunately at a quick glance, I think I just blurred the difference between the two definitions, which is why I said 'Indicated / True Air Speed' as if it were interchangeable. In the end, all I was trying to do was put my reasoning into grenadiac's original post which is below: [QUOTE=Grenadiac;46822102]Storm conditions can create a situation in which a plane's wings do not generate enough lift to maintain altitude. If that goes on long enough the aircraft will be falling too fast to recover by the time it exits that region. That said, they think it's mostly intact on the seafloor. It'll be interesting to see what the investigation turns up.[/QUOTE] While it is true I am not an airplane buff, I felt I had understood enough for this theory to make sense to me, and tried to use my own theories in order to give it more to work on. Either I didn't explain myself well enough, or some of the fundamentals I felt I understood were flawed in some way. But I guess in the end, all I was doing was putting out fires with a can of gasoline.
Gold star for finding signs of this one. Here's hoping they find everyone, alive or not, and get them back home.
really great they found some stuff so early on, extremely saddening that it did turn out to be a pretty bad crash :(
[QUOTE=Big Dumb American;46822380]A tailwind physically pushes the plane forward. It is actually preferred to fly with a strong tailwind, because it saves on fuel costs and boosts your travel speed. Take off and land in a headwind for a quicker and shorter takeoff and landing, and travel with a tailwind if possible. Source: I'm a pilot.[/QUOTE] Was looking for someone in this thread who actually knew something about aviation. Thank god I found one.
[QUOTE=oakman26;46823222]<stuff>[/QUOTE] Nice one dude. Nailed it.
Indonesian aviation is like a wild west, but Air Asia Indo was one of the best. My guess is some sort of windshear damaged the structure or something. Could've taken a quick dive. [editline]30th December 2014[/editline] I see there's some debate about how airspeed works. Why? Indicated Airspeed is read literally from the ram-air coming through the pitot-static system and is displayed on the airspeed indicator in the cockpit. If the aircraft has a tailwind, the groundspeed is going to tend to increase. Aircraft equipped with more advanced equipment such as GPS (we have them in our little piper archers, equipment Golf) can provide a rough estimate of your groundspeed. You can bet they had some way to tell their groundspeed in their A320s. The term "wind shear" relates to sudden differences in wind direction and speed, and could happen anywhere in the atmosphere, but when you encounter a more unstable air mass (such as a powerful storm producing up & downtrafts (lots of air moving around), precipitation and possibly other hazards like hail) you're going to be experiencing rougher air as the aircraft is blown around by the sudden changes in the movement of the air mass. Really, really bad wind shear is common with thunderstorms, so are things like microbursts. We can look at Delta Flight 191, a Boeing 727 that flew through a storm cloud 2 miles from KDFW and hit a microburst. It forced the jet downward and it ended up hitting some stuff on the ground, breaking the plane apart. Thunderstorms [B]are able[/B] to take down aircraft of any size, even an A320. From what can be told, the pilots requested an altitude change to avoid the hazard. Maybe if ATC had been able to issue a clearance to deviate, the accident could have been avoided altogether. When we talk about some "eerie similarity" to MH370, what are we talking about? IIRC it took a relatively clear and stormless route before fucking up. If some of you are implying that there's some large deception going on with regards to these aircraft crashing, stop playing make-believe and use your actual physical eyes. The pilots couldn't deviate from a storm, storms can cause crashes, this was a bad storm, bam, they're in the water. And yes, aircraft can fly with a tailwind. As long as they have enough headwind to fly at a comfortable speed and aren't rapidly changing the force of the wind on the aircraft, they're not gonna be at risk of fucking crashing. The point here is that within a storm, there are lots of rapid changes in wind speed and direction that can be rapid and strong enough to cause a medium-sized passenger jet to go down.
[QUOTE=Leintharien;46823551]Okay so let's see how much I can clarify here: Yeah that's the word I was looking for. I admit I look like a bit of a cock calling it like that, but for the life of me I couldn't remember the name and I was too lazy to look it up.[/QUOTE] You've clarified that you're autistic, and don't worry, you came across as a cock either way. Good job.
[QUOTE=circuitbawx;46824057]Indonesian aviation is like a wild west, but Air Asia Indo was one of the best. My guess is some sort of windshear damaged the structure or something. Could've taken a quick dive. [editline]30th December 2014[/editline] I see there's some debate about how airspeed works. Why? Indicated Airspeed is read literally from the ram-air coming through the pitot-static system and is displayed on the airspeed indicator in the cockpit. If the aircraft has a tailwind, the groundspeed is going to tend to increase. Aircraft equipped with more advanced equipment such as GPS (we have them in our little piper archers, equipment Golf) can provide a rough estimate of your groundspeed. You can bet they had some way to tell their groundspeed in their A320s. The term "wind shear" relates to sudden differences in wind direction and speed, and could happen anywhere in the atmosphere, but when you encounter a more unstable air mass (such as a powerful storm producing up & downtrafts (lots of air moving around), precipitation and possibly other hazards like hail) you're going to be experiencing rougher air as the aircraft is blown around by the sudden changes in the movement of the air mass. Really, really bad wind shear is common with thunderstorms, so are things like microbursts. We can look at Delta Flight 191, a Boeing 727 that flew through a storm cloud 2 miles from KDFW and hit a microburst. It forced the jet downward and it ended up hitting some stuff on the ground, breaking the plane apart. Thunderstorms [B]are able[/B] to take down aircraft of any size, even an A320. From what can be told, the pilots requested an altitude change to avoid the hazard. Maybe if ATC had been able to issue a clearance to deviate, the accident could have been avoided altogether. When we talk about some "eerie similarity" to MH370, what are we talking about? IIRC it took a relatively clear and stormless route before fucking up. If some of you are implying that there's some large deception going on with regards to these aircraft crashing, stop playing make-believe and use your actual physical eyes. The pilots couldn't deviate from a storm, storms can cause crashes, this was a bad storm, bam, they're in the water. And yes, aircraft can fly with a tailwind. As long as they have enough headwind to fly at a comfortable speed and aren't rapidly changing the force of the wind on the aircraft, they're not gonna be at risk of fucking crashing. The point here is that within a storm, there are lots of rapid changes in wind speed and direction that can be rapid and strong enough to cause a medium-sized passenger jet to go down.[/QUOTE] IAS, GS and TAS are all very granular differences that the average Joe may not be used to thinking about. I think you've done a great job explaining IAS. GS is the speed you are traveling over the ground, and TAS is the speed at which the aircraft is flying through the air. Indicated airspeed is just an indicative reading by the instrument used as a navigational aid, as you've said above. Nice page explaining it all here, for anyone interested: [url]http://www.decodedscience.com/airspeed-of-an-aircraft-indicated-airspeed-ias-and-true-airspeed-tas/5035[/url] (had to sanity check my own thoughts)
So what's facepunch's air crash investigation units final opinion?
[QUOTE=Complifused;46828762]So what's facepunch's air crash investigation units final opinion?[/QUOTE] It wasn't aliums
Probably not lupus?
[QUOTE=Complifused;46828762]So what's facepunch's air crash investigation units final opinion?[/QUOTE] Clearly there's some sort of spacetime vortex just like the bermuda triangle, except this time it's growing. Final verdict would be find the cultists responsible and sacrifice them to the appropriate gods in hopes our flying tin cans survive their journeys over Indonesia.
Wait, so...no May day or We are in distress call sign? BUT, the passengers seemed to be holding hands.... Questions: Is the Java sea known for big waves/storms? Why a crash-landing would be attempted but without emitting may day?
[QUOTE=Cutthecrap;46831438]Wait, so...no May day or We are in distress call sign? BUT, the passengers seemed to be holding hands.... Questions: Is the Java sea known for big waves/storms? Why a crash-landing would be attempted but without emitting may day?[/QUOTE] Who knows. The pilots could have been focused on trying to straighten out the plane - under that much pressure and fear for your life you probably wouldn't be thinking straightly.
[QUOTE=Big Dumb American;46822815]Ye, airspeed and ground speed are very different. Remember that your plane is pulling itself through the air, but the air is also moving over the ground. It is possible to have zero, or even negative, groundspeed (the rate at which your aircraft moves over the ground) while still traveling through the air (airspeed). I've done it a couple of times during training. In a light enough aircraft with a low enough stall speed, you can face into a strong winds, lower your flaps and raise the nose (maximizing lift), and reduce your airspeed to the minimum limit and actually hover in place, or even move backwards, relative to the ground.[/QUOTE] See: [IMG]http://i.imgur.com/NBzNY5M.gif[/IMG] I'm guessing loss of orientation/equipment failure led to the pilot to do an emergency water landing, or the plane hit enough turbulence to stall and spin in a way knocking the crew and passengers unconscious, and the plane crashing off the coast of Borneo.
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