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http://en.wikipedia.org/wiki/Wing_loading#Effect_on_climb_rate_and_cruise_performance
the first paragraph is almost completely wrong.
The climb performance depends on the amount of energy the motors can provide minus the amount of energy required to stay in the air divided by the weight of the plane. For example, a guy put a propellor and some bike pedals under his paraglider. Motor power (human power) was less than the power required to stay airborne. So he had very bad "climb performance" but still a low wingloading (as is normal with paragliders). So the wingloading DOES play a role, but it is not the main factor.
This is completely wrong. The wingloading does not play a role at all. The amount of energy required to transport a weight over a distance is the weight * distance / glide ratio. Nowhere does the wing loading play a role.
Suppose I build an exact (1:1) copy of the 747 which is 100 times lighter. It will have a 100x lower wingloading, it will have 10x slower flightspeed, but the same glide ratio (about 14). To transport 1kg with either the real 747 or the copy takes the same amount of energy. Of course, to transport a ton of payload the original 747 will have to transport a whole 747 from A to B as well, so the lighter airplane will be more efficient. But that's because it's lighter and not because it has a lower wingloading. -- REW jan 31 2010. —Preceding unsigned comment added by 95.36.47.159 ( talk) 16:09, 31 January 2010 (UTC)
On further reading, the rest of the chapter is bogus as well. "how rapidly the climb is established" is the most glaring problem. It simply comes down to the energy equations. So the energy of the system is m*g*h + 1/2 m v^2. Depleted is: m * g * Sink-rate and added is motor-thrust * airspeed.
If you're in level flight and suddenly point the nose up, you trade speed (1/2 m v^2) for height (m.g.h). The accelleration required will cause an AOA change sufficient to provide the neccesary force.
(if you suddenly point the nose upward while almost at stallspeed, you will stall if the momentary AOA is too high...) —Preceding unsigned comment added by 95.36.47.159 ( talk) 17:22, 31 January 2010 (UTC)
An important aspect of wing loading that is not discussed in this article is that of the vertical acceleration of an aircraft as it encounters a vertical gust. When encountering vertical gusts, as the angle of attack and, therefore, the lift produced, changes, the aircraft with the higher wing loading will experience lower vertical acceleration due to its greater relative mass. The effect of this is that aircraft with high wing loadings ride more smoothly through turbulence. This is why modern jetliners handle turbulence so much more nicely than general aviation aircraft or older airliners. Perhaps this wording is not how it should appear in the actual article, but I think the article should mention this, since it's an effect most people will experience themselves, and a factor that is much more effected by wing loading than either cruising or climb performance. Harleygnuya ( talk) 22:29, 8 August 2017 (UTC)
I'm no engineer, but if "wing loading is the loaded weight of the aircraft divided by the area of the wing" then in metric shouldn't it be measured in N/m² instead of kg/m²? Blaise 21:08, July 19, 2005 (UTC)
With respect, and in lower case, the pound is a unit of mass. Any scientific dictionary will tell you this. I have the paperback "A Dictionary of Physical Sciences" ed Daintith pub Pan) in front of me and it defines the pound as "an imperial unit of mass equal to 0.453 592 37 kg". There are related imperial force units: the poundal (force need to accelerate a mass of 1 lb at 1 ft/sec/sec); the pound-weight (symbol lbwt, the force that would accelerate a mass of 1 lb at the local value of g); and the pound force (lbf, the force that would accelerate a mass of 1 lb at a fixed value (standard acceleration) of 32.174 ft/sec/sec, not far from the value of g anywhere near the Earth's surface).
Aircraft "weights" are given in mass units, lb or kg; engine thrusts in force units, lbf or N.
In pounds-weight the gravitational force on a body stays the same wherever you are, because the unit depends on the local g value; the force in pounds-force or poundals does vary slightly with position, with g. So of course does the force in Newtons. If we measure the wing loading as mass/area which is the commonest way (ie in lb/ft2 or kg/m2) then g is not involved. If anyone were to use pounds-weight/area, that too would be position independent. I don't recall seeing anyone using (pounds-force or poundals)/ft2 either, though they might; N/m2 is used. All of these give a loading which is position dependent.
Do we need to worry about such variations when calculating a number not usually quoted to better than 1% (think of variations in mass during a flight, or even from one take off to the next)? The value of g is highest at the pole, greater than at the equator by a factor about 1.0053, or 0.5%. g also falls with height and it is easy to calculate that an aircraft (we are talking wing loading) at 20 km will experience a fall in g by about a factor 0.994, or a fall of 0.6%. So these effects, whilst real enough are probably not of much consequence to engineers. In any case, as I said in the usual mass/area units (rather than force/area) wing loadings are independent of position. TSRL ( talk) 20:49, 11 April 2009 (UTC)
I would really like to see some discussion of wing loading in flying animals. All the discussion ignores animals altogether, and perhaps the article should be reworded to reflect the fact that wing loading applies to more things than man-made aircraft. John.Conway 19:05, 23 December 2005 (UTC)
This page really needs some references, and sections would help it's readability. John.Conway 19:05, 23 December 2005 (UTC)
This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:06, 10 November 2007 (UTC)
This needs another look: there are many lower and higher values than quoted here and the impression is given, wrongly, that only fighters have high wing loadings. To pull out a couple of data, the little Cessna 152 has a WL of 51 kg m-2, and the Boeing 747 740 kg m-2. The data is on WikiP, but it would be nice to have a table: lowest (-ish) typical that, typical this - biggest (-ish) to give a better feel for the numbers. The intention of what we have is right but not the detail.
I think it might help, too, to spend a bit longer on wing loading and level fight, before getting into the manoeuverability issues. Needs a bit of thought and perhaps even a formula. TSRL ( talk) 20:56, 4 December 2008 (UTC)
Maybe I am being dim, but I'm baffled by the second sentence from the start, which talks of a broad connection between wing loading and L/M. The former is a well defined property of an aircraft at a given mass. The latter, particularly the lift depends on speed, altitude and attitude: it's not a property of an aircraft, or at least only an instantaneous one. Can there be a significant relationship? TSRL ( talk) 21:42, 4 December 2008 (UTC)
In Stick and Rudder, Langewiesche talks about the technical (read 'accurate') definition of "lift." An aircraft's lift at any given moment is congruent to its weight; otherwise it would balloon upward or descend. Langewiesche ends up using the term "buoyancy" to describe what this article terms as "lift," but only after an explanation that may not be appropriate here. In the interest of keeping Wikipedia accurate- semantically and otherwise- can anyone come up with a better way to refer to "lift?" -- 99.180.72.12 ( talk) 03:56, 30 January 2009 (UTC)
Aircraft climb as a result of "excess power" not lift! —Preceding unsigned comment added by 134.129.221.252 ( talk) 00:11, 16 April 2009 (UTC)
Does the wing area given include that of the tailplane and/or other surfaces, e.g. canard wings? Thanks. -- TraceyR ( talk) 16:22, 4 June 2010 (UTC)
The entire section titled Effect on climb rate and cruise performance is unsourced. In its entirety, it is technically unsound. It appears to have been written using nothing but intuition. For example, it implies that for an aircraft to climb requires that lift exceed weight. That is incorrect - climbing requires that thrust exceed drag. See Rate of climb and Angle of climb.
I am happy to re-write the section, based on reliable published sources. But first I will erase the entire section. It is worse than misleading. Dolphin ( t) 05:10, 29 March 2018 (UTC)
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http://en.wikipedia.org/wiki/Wing_loading#Effect_on_climb_rate_and_cruise_performance
the first paragraph is almost completely wrong.
The climb performance depends on the amount of energy the motors can provide minus the amount of energy required to stay in the air divided by the weight of the plane. For example, a guy put a propellor and some bike pedals under his paraglider. Motor power (human power) was less than the power required to stay airborne. So he had very bad "climb performance" but still a low wingloading (as is normal with paragliders). So the wingloading DOES play a role, but it is not the main factor.
This is completely wrong. The wingloading does not play a role at all. The amount of energy required to transport a weight over a distance is the weight * distance / glide ratio. Nowhere does the wing loading play a role.
Suppose I build an exact (1:1) copy of the 747 which is 100 times lighter. It will have a 100x lower wingloading, it will have 10x slower flightspeed, but the same glide ratio (about 14). To transport 1kg with either the real 747 or the copy takes the same amount of energy. Of course, to transport a ton of payload the original 747 will have to transport a whole 747 from A to B as well, so the lighter airplane will be more efficient. But that's because it's lighter and not because it has a lower wingloading. -- REW jan 31 2010. —Preceding unsigned comment added by 95.36.47.159 ( talk) 16:09, 31 January 2010 (UTC)
On further reading, the rest of the chapter is bogus as well. "how rapidly the climb is established" is the most glaring problem. It simply comes down to the energy equations. So the energy of the system is m*g*h + 1/2 m v^2. Depleted is: m * g * Sink-rate and added is motor-thrust * airspeed.
If you're in level flight and suddenly point the nose up, you trade speed (1/2 m v^2) for height (m.g.h). The accelleration required will cause an AOA change sufficient to provide the neccesary force.
(if you suddenly point the nose upward while almost at stallspeed, you will stall if the momentary AOA is too high...) —Preceding unsigned comment added by 95.36.47.159 ( talk) 17:22, 31 January 2010 (UTC)
An important aspect of wing loading that is not discussed in this article is that of the vertical acceleration of an aircraft as it encounters a vertical gust. When encountering vertical gusts, as the angle of attack and, therefore, the lift produced, changes, the aircraft with the higher wing loading will experience lower vertical acceleration due to its greater relative mass. The effect of this is that aircraft with high wing loadings ride more smoothly through turbulence. This is why modern jetliners handle turbulence so much more nicely than general aviation aircraft or older airliners. Perhaps this wording is not how it should appear in the actual article, but I think the article should mention this, since it's an effect most people will experience themselves, and a factor that is much more effected by wing loading than either cruising or climb performance. Harleygnuya ( talk) 22:29, 8 August 2017 (UTC)
I'm no engineer, but if "wing loading is the loaded weight of the aircraft divided by the area of the wing" then in metric shouldn't it be measured in N/m² instead of kg/m²? Blaise 21:08, July 19, 2005 (UTC)
With respect, and in lower case, the pound is a unit of mass. Any scientific dictionary will tell you this. I have the paperback "A Dictionary of Physical Sciences" ed Daintith pub Pan) in front of me and it defines the pound as "an imperial unit of mass equal to 0.453 592 37 kg". There are related imperial force units: the poundal (force need to accelerate a mass of 1 lb at 1 ft/sec/sec); the pound-weight (symbol lbwt, the force that would accelerate a mass of 1 lb at the local value of g); and the pound force (lbf, the force that would accelerate a mass of 1 lb at a fixed value (standard acceleration) of 32.174 ft/sec/sec, not far from the value of g anywhere near the Earth's surface).
Aircraft "weights" are given in mass units, lb or kg; engine thrusts in force units, lbf or N.
In pounds-weight the gravitational force on a body stays the same wherever you are, because the unit depends on the local g value; the force in pounds-force or poundals does vary slightly with position, with g. So of course does the force in Newtons. If we measure the wing loading as mass/area which is the commonest way (ie in lb/ft2 or kg/m2) then g is not involved. If anyone were to use pounds-weight/area, that too would be position independent. I don't recall seeing anyone using (pounds-force or poundals)/ft2 either, though they might; N/m2 is used. All of these give a loading which is position dependent.
Do we need to worry about such variations when calculating a number not usually quoted to better than 1% (think of variations in mass during a flight, or even from one take off to the next)? The value of g is highest at the pole, greater than at the equator by a factor about 1.0053, or 0.5%. g also falls with height and it is easy to calculate that an aircraft (we are talking wing loading) at 20 km will experience a fall in g by about a factor 0.994, or a fall of 0.6%. So these effects, whilst real enough are probably not of much consequence to engineers. In any case, as I said in the usual mass/area units (rather than force/area) wing loadings are independent of position. TSRL ( talk) 20:49, 11 April 2009 (UTC)
I would really like to see some discussion of wing loading in flying animals. All the discussion ignores animals altogether, and perhaps the article should be reworded to reflect the fact that wing loading applies to more things than man-made aircraft. John.Conway 19:05, 23 December 2005 (UTC)
This page really needs some references, and sections would help it's readability. John.Conway 19:05, 23 December 2005 (UTC)
This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:06, 10 November 2007 (UTC)
This needs another look: there are many lower and higher values than quoted here and the impression is given, wrongly, that only fighters have high wing loadings. To pull out a couple of data, the little Cessna 152 has a WL of 51 kg m-2, and the Boeing 747 740 kg m-2. The data is on WikiP, but it would be nice to have a table: lowest (-ish) typical that, typical this - biggest (-ish) to give a better feel for the numbers. The intention of what we have is right but not the detail.
I think it might help, too, to spend a bit longer on wing loading and level fight, before getting into the manoeuverability issues. Needs a bit of thought and perhaps even a formula. TSRL ( talk) 20:56, 4 December 2008 (UTC)
Maybe I am being dim, but I'm baffled by the second sentence from the start, which talks of a broad connection between wing loading and L/M. The former is a well defined property of an aircraft at a given mass. The latter, particularly the lift depends on speed, altitude and attitude: it's not a property of an aircraft, or at least only an instantaneous one. Can there be a significant relationship? TSRL ( talk) 21:42, 4 December 2008 (UTC)
In Stick and Rudder, Langewiesche talks about the technical (read 'accurate') definition of "lift." An aircraft's lift at any given moment is congruent to its weight; otherwise it would balloon upward or descend. Langewiesche ends up using the term "buoyancy" to describe what this article terms as "lift," but only after an explanation that may not be appropriate here. In the interest of keeping Wikipedia accurate- semantically and otherwise- can anyone come up with a better way to refer to "lift?" -- 99.180.72.12 ( talk) 03:56, 30 January 2009 (UTC)
Aircraft climb as a result of "excess power" not lift! —Preceding unsigned comment added by 134.129.221.252 ( talk) 00:11, 16 April 2009 (UTC)
Does the wing area given include that of the tailplane and/or other surfaces, e.g. canard wings? Thanks. -- TraceyR ( talk) 16:22, 4 June 2010 (UTC)
The entire section titled Effect on climb rate and cruise performance is unsourced. In its entirety, it is technically unsound. It appears to have been written using nothing but intuition. For example, it implies that for an aircraft to climb requires that lift exceed weight. That is incorrect - climbing requires that thrust exceed drag. See Rate of climb and Angle of climb.
I am happy to re-write the section, based on reliable published sources. But first I will erase the entire section. It is worse than misleading. Dolphin ( t) 05:10, 29 March 2018 (UTC)