Downwind turn Myth
01-21-2014, 06:16 AM
#1202
My Feedback: (57)
Aaaarrggh,
Blue Bus, you're not listening. You keep bringing up gusty conditions which have NOTHING to do with the "downwind turn myth". The fact that you think gusts are relevant demonstrates that you don't even get the gist of what the "downwind turn myth" is. None the less, whiteout understanding what it's even about, you SEEM to believe the myth is true. Pretty confused.
I have, against my better judgement, engaged you on the gusty topic, which is a whole different scenario, and you also fail to discern my point on those posts either. You misunderstand what a "gust" is and how air currents move. The "gusty" scenario is interesting and valid and something that must be understood in order to be a good pilot. But it IS separate from the Downwind Turn in STEADY wind scenario which HighHorse was just referring to. You must understand the theory and reality of the steady wind scenario before you can understand the more complex situation where gusts are superimposed on it. You understand neither.
When someone makes a clear point, you jump into a different scenario to dispel it, which is not very logical nor intellectually honest. I must question you motives. Honestly, I can't see how someone with your mind set gets to be an instructor. Please go back to the start of this thread and read it through before you rehash stuff that was thoroughly debunked 30 pages ago. And remember, EVERYTHING that HighHorse and I have said in this thread is carefully worded and iron clad true. NOBODY has shown any credible evidence to the contrary.
Blue Bus, you're not listening. You keep bringing up gusty conditions which have NOTHING to do with the "downwind turn myth". The fact that you think gusts are relevant demonstrates that you don't even get the gist of what the "downwind turn myth" is. None the less, whiteout understanding what it's even about, you SEEM to believe the myth is true. Pretty confused.
I have, against my better judgement, engaged you on the gusty topic, which is a whole different scenario, and you also fail to discern my point on those posts either. You misunderstand what a "gust" is and how air currents move. The "gusty" scenario is interesting and valid and something that must be understood in order to be a good pilot. But it IS separate from the Downwind Turn in STEADY wind scenario which HighHorse was just referring to. You must understand the theory and reality of the steady wind scenario before you can understand the more complex situation where gusts are superimposed on it. You understand neither.
When someone makes a clear point, you jump into a different scenario to dispel it, which is not very logical nor intellectually honest. I must question you motives. Honestly, I can't see how someone with your mind set gets to be an instructor. Please go back to the start of this thread and read it through before you rehash stuff that was thoroughly debunked 30 pages ago. And remember, EVERYTHING that HighHorse and I have said in this thread is carefully worded and iron clad true. NOBODY has shown any credible evidence to the contrary.
01-21-2014, 06:31 AM
#1203
Jay,
I don't know if you read the whole thread,but I tried to explain earlier how flying from a fixed,ground based location,can cause speed perception issues that lead to problems with a low energy,downwind turn,in our rc application. I was summarily dismissed. Don't waste your time fighting this one. These guys are super smart. I only have 18000 hrs,a masters in aeronautical science,and 38 years of rc experience. I am still learning though,every day.
Erik
I don't know if you read the whole thread,but I tried to explain earlier how flying from a fixed,ground based location,can cause speed perception issues that lead to problems with a low energy,downwind turn,in our rc application. I was summarily dismissed. Don't waste your time fighting this one. These guys are super smart. I only have 18000 hrs,a masters in aeronautical science,and 38 years of rc experience. I am still learning though,every day.
Erik
01-21-2014, 07:18 AM
#1204
Senior Member
"This little thing doesn't have any power to spare"
And it can hover??? That's really a sign of at least some spare power.
Perception of what is happening - - -
From in the airplane relative to movement over the ground was addressed earlier in the thread.
From the ground, perception is a bit different, and the general idea is to increase power/airspeed when things look like they may be getting iffy, due to wind or other conditions. Upwind or downwind makes no difference to the plane, since it is flying relative to the wind, not the ground. Landing downwind can be a problem, because it increases ground speed and so forth.
"The model looked like it was flying too fast, so I slowed it down, and it stalled". This is the result of a false understanding/perception of what is going on. Back in the days before full size A/C had instruments, and a pilot did not have a good "seat of the pants" approach to flying, real trouble could result.
This is still worry-some, since may airline pilots are trained and used to flying "by the numbers" (Instruments) and ignore other indications as to what is going on. In light "complex" single engine planes, actual IFR flight into and out of terminal areas, holding patterns, etc. can really task a single pilot.
Many years ago, (70's) an international flight with a Piper Arrow in actual IFR and light icing conditions (not anticipated), followed by a request to "expedite" a full IFR/instrument landing at the destination or go into a holding pattern after I had turned final, slowed down, had the gear down, etc. made me decide to "expedite", since I had no desire to try to go around and enter a holding pattern, just to make the approach, and so forth all over again.
Anyway, I did a fast "cleanup", added quite a bit to the normal approach speeds, and got a message from the controller - - - "I don't want to know what you are doing, but keep it up, land a bit long, and take any of the high speed turn outs that you can safely use". There is a (Boeing something or other) scheduled jet airliner behind you that has a landing speed that is more than twice yours.
And it can hover??? That's really a sign of at least some spare power.
Perception of what is happening - - -
From in the airplane relative to movement over the ground was addressed earlier in the thread.
From the ground, perception is a bit different, and the general idea is to increase power/airspeed when things look like they may be getting iffy, due to wind or other conditions. Upwind or downwind makes no difference to the plane, since it is flying relative to the wind, not the ground. Landing downwind can be a problem, because it increases ground speed and so forth.
"The model looked like it was flying too fast, so I slowed it down, and it stalled". This is the result of a false understanding/perception of what is going on. Back in the days before full size A/C had instruments, and a pilot did not have a good "seat of the pants" approach to flying, real trouble could result.
This is still worry-some, since may airline pilots are trained and used to flying "by the numbers" (Instruments) and ignore other indications as to what is going on. In light "complex" single engine planes, actual IFR flight into and out of terminal areas, holding patterns, etc. can really task a single pilot.
Many years ago, (70's) an international flight with a Piper Arrow in actual IFR and light icing conditions (not anticipated), followed by a request to "expedite" a full IFR/instrument landing at the destination or go into a holding pattern after I had turned final, slowed down, had the gear down, etc. made me decide to "expedite", since I had no desire to try to go around and enter a holding pattern, just to make the approach, and so forth all over again.
Anyway, I did a fast "cleanup", added quite a bit to the normal approach speeds, and got a message from the controller - - - "I don't want to know what you are doing, but keep it up, land a bit long, and take any of the high speed turn outs that you can safely use". There is a (Boeing something or other) scheduled jet airliner behind you that has a landing speed that is more than twice yours.
Last edited by chuckk2; 01-21-2014 at 07:57 AM.
01-21-2014, 08:08 AM
#1205
"This little thing doesn't have any power to spare"
And it can hover??? That's really a sign of at least some spare power.
Perception of what is happening - - -
From in the airplane relative to movement over the ground was addressed earlier in the thread.
From the ground, perception is a bit different, and the general idea is to increase power/airspeed when things look like they may be getting iffy, due to wind or other conditions. Upwind or downwind makes no difference to the plane, since it is flying relative to the wind, not the ground. Landing downwind can be a problem, because it increases ground speed and so forth.
"The model looked like it was flying too fast, so I slowed it down, and it stalled". This is the result of a false understanding/perception of what is going on. Back in the days before full size A/C had instruments, and a pilot did not have a good "seat of the pants" approach to flying, real trouble could result.
This is still worry-some, since may airline pilots are trained and used to flying "by the numbers" (Instruments) and ignore other indications as to what is going on. In light "complex" single engine planes, actual IFR flight into and out of terminal areas, holding patterns, etc. can really task a single pilot.
Many years ago, (70's) an international flight with a Piper Arrow in actual IFR and light icing conditions (not anticipated), followed by a request to "expedite" a full IFR/instrument landing at the destination or go into a holding pattern after I had turned final, slowed down, had the gear down, etc. made me decide to "expedite", since I had no desire to try to go around and enter a holding pattern, just to make the approach, and so forth all over again.
Anyway, I did a fast "cleanup", added quite a bit to the normal approach speeds, and got a message from the controller - - - "I don't want to know what you are doing, but keep it up, land a bit long, and take any of the high speed turn outs that you can safely use". There is a (Boeing something or other) scheduled jet airliner behind you that has a landing speed that is more than twice yours.
And it can hover??? That's really a sign of at least some spare power.
Perception of what is happening - - -
From in the airplane relative to movement over the ground was addressed earlier in the thread.
From the ground, perception is a bit different, and the general idea is to increase power/airspeed when things look like they may be getting iffy, due to wind or other conditions. Upwind or downwind makes no difference to the plane, since it is flying relative to the wind, not the ground. Landing downwind can be a problem, because it increases ground speed and so forth.
"The model looked like it was flying too fast, so I slowed it down, and it stalled". This is the result of a false understanding/perception of what is going on. Back in the days before full size A/C had instruments, and a pilot did not have a good "seat of the pants" approach to flying, real trouble could result.
This is still worry-some, since may airline pilots are trained and used to flying "by the numbers" (Instruments) and ignore other indications as to what is going on. In light "complex" single engine planes, actual IFR flight into and out of terminal areas, holding patterns, etc. can really task a single pilot.
Many years ago, (70's) an international flight with a Piper Arrow in actual IFR and light icing conditions (not anticipated), followed by a request to "expedite" a full IFR/instrument landing at the destination or go into a holding pattern after I had turned final, slowed down, had the gear down, etc. made me decide to "expedite", since I had no desire to try to go around and enter a holding pattern, just to make the approach, and so forth all over again.
Anyway, I did a fast "cleanup", added quite a bit to the normal approach speeds, and got a message from the controller - - - "I don't want to know what you are doing, but keep it up, land a bit long, and take any of the high speed turn outs that you can safely use". There is a (Boeing something or other) scheduled jet airliner behind you that has a landing speed that is more than twice yours.
01-22-2014, 08:56 PM
#1207
My Feedback: (57)
Jay,
I don't know if you read the whole thread,but I tried to explain earlier how flying from a fixed,ground based location,can cause speed perception issues that lead to problems with a low energy,downwind turn,in our rc application. I was summarily dismissed. Don't waste your time fighting this one. These guys are super smart. I only have 18000 hrs,a masters in aeronautical science,and 38 years of rc experience. I am still learning though,every day.
Erik
I don't know if you read the whole thread,but I tried to explain earlier how flying from a fixed,ground based location,can cause speed perception issues that lead to problems with a low energy,downwind turn,in our rc application. I was summarily dismissed. Don't waste your time fighting this one. These guys are super smart. I only have 18000 hrs,a masters in aeronautical science,and 38 years of rc experience. I am still learning though,every day.
Erik
Always fun for me to debate other adult professionals on aviation topics, but I must admit it gets challenging when some start to throw all sorts of pseudoscience based remarks & incorrect terminology just to say someone of my background doesn't understand "wind"..lol Oh well, most of us realize we are students of aviation for life & there is always more to learn.
Last edited by BlueBus320; 01-23-2014 at 04:38 AM.
01-23-2014, 05:21 AM
#1208
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Should I open the topic of hovering out of ground effect in a helicopter? Facing into wind then turning to face downwind.
Depending on the performance margin of your helicopter, weight, temp and altitude it can be very dangerous and that's no myth.
Depending on the performance margin of your helicopter, weight, temp and altitude it can be very dangerous and that's no myth.
Last edited by Rob2160; 01-23-2014 at 05:33 AM.
01-23-2014, 06:21 AM
#1209
The myths that present them selves in Aviation, and even more so in R/C, are many and just like the guy that says U don't need Rudder (Never uses it except on the ground) Will never, even when presented with the most scientifically proven arguments, Choose not to believe in these myths no mater what. The same thing in High wind conditions the guy will say see how fast my plane is going Down wind and practically stopped Up Wind when landing. U will never convince him that wind (Not turbulence or gusts) have any affect on a planes flying ability. I have Never in 26 years and some 1700 hours of full scale flying (In 24 or so different Air Craft) ever seen a drop in indicated air speed on a down wind turn in other than Wind Shear Conditions. We will never convince the Myth believer of the Truth. They just can't concive that they (are/can) be wrong PERIOD.
01-23-2014, 06:28 AM
#1210
You know what they call a doctor who just barely passes medical school?......He still gets to be called "Doctor". Even if he's top of the class and becomes a brain surgeon, he's still not qualified to perform a great many medical procedures.
Same with this debate. You've got 50,000 hours flying at 30,000 ft, my hat's off to you. You been flying Rc planes since 1955? Good for you, does either one of these things mean you know "it all", or that I would trust you to fly my 1/4 scale cub 4 feet high and make a low energy downwind turn? ........... NOPE.
Same with this debate. You've got 50,000 hours flying at 30,000 ft, my hat's off to you. You been flying Rc planes since 1955? Good for you, does either one of these things mean you know "it all", or that I would trust you to fly my 1/4 scale cub 4 feet high and make a low energy downwind turn? ........... NOPE.
01-23-2014, 08:30 AM
#1211
My Feedback: (57)
Agreed Hugger-4641
Here is an excerpt from the original post of this thread:
"Once an a/c has broken ground, steady state winds have no effect on airspeed (hence, lift) whatsoever, and airspeed does not change simply because one is flying upwind, downwind, crosswind, or even when alternating between any combinations of the above. Period. That is the beginning, middle, and end of the story".
I remember back in grade school, a true/false statement presented in this manner will usually need to be answered as"false". The reason being, is you could show up with a hundred different aircraft, & take 1000 tries at stalling each (in every configuration) during a downwind turn, you'd only have to be successful one time to dispel this entire statement.
I know for the most part this statement is absolutely correct during "normal flight", but it neglects to address low energy/ high alpha flight where in theory the laws of physics will play a large part in the aircrafts inability to maintain airspeed during an abrupt turn to a down wind leg.
Aviation is an extremely dynamic & versatile science often making what is thought to be the impossible possible.
Here is an excerpt from the original post of this thread:
"Once an a/c has broken ground, steady state winds have no effect on airspeed (hence, lift) whatsoever, and airspeed does not change simply because one is flying upwind, downwind, crosswind, or even when alternating between any combinations of the above. Period. That is the beginning, middle, and end of the story".
I remember back in grade school, a true/false statement presented in this manner will usually need to be answered as"false". The reason being, is you could show up with a hundred different aircraft, & take 1000 tries at stalling each (in every configuration) during a downwind turn, you'd only have to be successful one time to dispel this entire statement.
I know for the most part this statement is absolutely correct during "normal flight", but it neglects to address low energy/ high alpha flight where in theory the laws of physics will play a large part in the aircrafts inability to maintain airspeed during an abrupt turn to a down wind leg.
Aviation is an extremely dynamic & versatile science often making what is thought to be the impossible possible.
Last edited by BlueBus320; 01-23-2014 at 08:34 AM.
01-23-2014, 08:55 AM
#1212
You know what they call a doctor who just barely passes medical school?......He still gets to be called "Doctor". Even if he's top of the class and becomes a brain surgeon, he's still not qualified to perform a great many medical procedures.
Same with this debate. You've got 50,000 hours flying at 30,000 ft, my hat's off to you. You been flying Rc planes since 1955? Good for you, does either one of these things mean you know "it all", or that I would trust you to fly my 1/4 scale cub 4 feet high and make a low energy downwind turn? ........... NOPE.
Same with this debate. You've got 50,000 hours flying at 30,000 ft, my hat's off to you. You been flying Rc planes since 1955? Good for you, does either one of these things mean you know "it all", or that I would trust you to fly my 1/4 scale cub 4 feet high and make a low energy downwind turn? ........... NOPE.
You know the guy who started this thread , thinks he knows it all , well good for him but why is he trying to convince us all that he is right and every one else is wrong .
We should all stop fuelling this nonsense , it is real useless
Maybe he is right but I'd rather be wrong .
01-23-2014, 09:07 AM
#1214
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The risk is the "low energy/high alpha" aspect of the turn regardless of being high or low, upwind, downwind or crosswind. Planes fall out of the sky when the wings can't generate enough lift to hold them up. That condition is usually pilot induced by mismanaging the energy the plane has available. If the myth is that planes stop flying when they make a turn going with the wind (down wind) and only because they are going downwind, how can it possibly be true? Don't we make left and right turns upwind and downwind all the time? if the myth is that a plane flying with low energy and high alpha is put into a banked turn and slowed even further with more elevator input to tighten the turn because it's drifting downwind and the pilots thinks "more is better" then yes, the wing will reach critical angle of attack, stall and possibly spin.
There really isn't a myth, just a misapplication of the controls. (or should I say Myth-application)
Jaybird
There really isn't a myth, just a misapplication of the controls. (or should I say Myth-application)
Jaybird
Last edited by Jaybird; 01-23-2014 at 09:10 AM.
01-23-2014, 09:11 AM
#1215
You are so right Man,
You know the guy who started this thread , thinks he knows it all , well good for him but why is he trying to convince us all that he is right and every one else is wrong .
We should all stop fuelling this nonsense , it is real useless
Maybe he is right but I'd rather be wrong .
You know the guy who started this thread , thinks he knows it all , well good for him but why is he trying to convince us all that he is right and every one else is wrong .
We should all stop fuelling this nonsense , it is real useless
Maybe he is right but I'd rather be wrong .
John
01-23-2014, 09:49 AM
#1216
Many here have pointed to references that say this myth is wrong. No one has shown any credible reference where it is right. Instead they try to qualify it with other issues such as wind gusts, a sudden bank, etc. These have nothing to do with the myth so Highhorse and others have been PROVEN to be right.
01-24-2014, 06:47 AM
#1217
There are many "references" that say the chicken came first, others say the egg came first. Neither can prove it, but by your logic, the first one to make a statement is right because no one can prove them wrong. Forgive me if I'm not convinced.
I wish I could build my own wind tunnel, and suspend a model so it can rise or fall freely, then subject it to a 20mph steady wind and trim it out so it is "flying" four or five feet high, then abruptly turn it 90 degrees, then 180 degrees and observe what happens. I'm inclined to believe the model would lose lift and fall. The problem with this is the model has no "inertia" nor is it free to accelerate once turned down wind. But I'm inclined to believe that even if the model was allowed to accelerate after being turned, it would still not accelerate quick enough to avoid losing some altitude.
Maybe someone with a wind tunnel can prove me wrong.
I wish I could build my own wind tunnel, and suspend a model so it can rise or fall freely, then subject it to a 20mph steady wind and trim it out so it is "flying" four or five feet high, then abruptly turn it 90 degrees, then 180 degrees and observe what happens. I'm inclined to believe the model would lose lift and fall. The problem with this is the model has no "inertia" nor is it free to accelerate once turned down wind. But I'm inclined to believe that even if the model was allowed to accelerate after being turned, it would still not accelerate quick enough to avoid losing some altitude.
Maybe someone with a wind tunnel can prove me wrong.
01-24-2014, 07:37 AM
#1218
My Feedback: (57)
There are many "references" that say the chicken came first, others say the egg came first. Neither can prove it, but by your logic, the first one to make a statement is right because no one can prove them wrong. Forgive me if I'm not convinced.
I wish I could build my own wind tunnel, and suspend a model so it can rise or fall freely, then subject it to a 20mph steady wind and trim it out so it is "flying" four or five feet high, then abruptly turn it 90 degrees, then 180 degrees and observe what happens. I'm inclined to believe the model would lose lift and fall. The problem with this is the model has no "inertia" nor is it free to accelerate once turned down wind. But I'm inclined to believe that even if the model was allowed to accelerate after being turned, it would still not accelerate quick enough to avoid losing some altitude.
Maybe someone with a wind tunnel can prove me wrong.
I wish I could build my own wind tunnel, and suspend a model so it can rise or fall freely, then subject it to a 20mph steady wind and trim it out so it is "flying" four or five feet high, then abruptly turn it 90 degrees, then 180 degrees and observe what happens. I'm inclined to believe the model would lose lift and fall. The problem with this is the model has no "inertia" nor is it free to accelerate once turned down wind. But I'm inclined to believe that even if the model was allowed to accelerate after being turned, it would still not accelerate quick enough to avoid losing some altitude.
Maybe someone with a wind tunnel can prove me wrong.
Microburst proves beyond a doubt that an aircraft as big as an L1011 (Delta 191) can be affected by air accelerating from behind. That is not linearly the same as our low energy theory, but it corroborates it.
01-24-2014, 07:54 AM
#1219
You are so right Man,
You know the guy who started this thread , thinks he knows it all , well good for him but why is he trying to convince us all that he is right and every one else is wrong .
We should all stop fuelling this nonsense , it is real useless
Maybe he is right but I'd rather be wrong .
You know the guy who started this thread , thinks he knows it all , well good for him but why is he trying to convince us all that he is right and every one else is wrong .
We should all stop fuelling this nonsense , it is real useless
Maybe he is right but I'd rather be wrong .
You know whats funny? You ignore the ENTIRE aerodynamic aviation community whom collectively have overwhelming evidence to support the FACT that no such thing exists at all, but you know better than they do. All of academia are wrong you and you are right. Yeah that must be it. You'd better call the President of Physics and get to the bottom of this!
Seriously, can anyone here who believes the myth, provide one shred of evidence beyond what they "think" happens? There is a preponderance of info that it doesn't. Can you seriously believe that something so basic that could potentially kill you would be missed like that? It simply doesn't pass the common sense test.....think abut it.
01-24-2014, 08:01 AM
#1220
Agreed again. Anyone that thinks this is "PROVEN", one way or another has no interest in finding the real answer. I would buy a big clipped wing cub, fit it with a telemetry capable air speed sensor, then take it out in (arbitrary) 20 mph winds. I would then film my 18MZ screen's IAS while simultaneously filming the plane. I am around 95% sure I could come up with a wind/airspeed combo that will produce a stall while turning downwind.
Microburst proves beyond a doubt that an aircraft as big as an L1011 (Delta 191) can be affected by air accelerating from behind. That is not linearly the same as our low energy theory, but it corroborates it.
Microburst proves beyond a doubt that an aircraft as big as an L1011 (Delta 191) can be affected by air accelerating from behind. That is not linearly the same as our low energy theory, but it corroborates it.
I've already done exactly this! I fly UAV's for a living. By nature they navigate via GPS waypoints (ground reference manuvers!) and are very highly instrumented! When turning downwind to final, or upwind to downwind, (our wind limits are 35 kts, which I've flown in many times) there is no change in IAS, ground speed changes of course, but not indicated. Your argument has no credibility. I have telemetry files to back it up.
Once again you are not grasping the issue at hand here, microbursts are NOT steady state wind, which is what this thread is about.
01-24-2014, 08:03 AM
#1221
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"...come up with a wind/airspeed combo that will produce a stall while turning downwind."
Of course you can...that's not a myth that's aerodynamics. Fly a plane slow enough and ANY increase in bank (wing loading) will produce a stall regardless of whether the plane is moving with or against the wind. The myth seems to be that the plane stops flying for some amount of time EVERYTIME it turns crosswind. Just doesn't make sense.
An airplane WILL loose lift in a banked turn if the AOA is not increased with the elevator to match the increase in wing loading. The plane always seeks a balanced energy state. When one thing is changed the plane will seek a balanced state unless something else is done to change it. A plane will start to loose altitude when banked (regardless of wind) because it now needs more airflow over the wing to make up for the increase in load on the wing and will drop it's nose. The PILOT can then stop the loss of altitude by adding elevator input to pick the nose back up. The increased AOA will now require more energy and the plane will slow down. Put in enough bank and the PILOT has to add elevator and power to maintain level flight.
The windtunnel scenario described also doesn't work to prove it. Since the wind in the tunnel moves in one direction and the plane is stationary (front to back even if it can go up and down) in the airflow, turning the stationary plane broadside to the airflow in the tunnel doesn't represent a plane flying through the air. In that case there is no airflow over the wings for lift. It would be like placing the plane on the ground and hitting it with a leaf blower from the side.
Jaybird
Of course you can...that's not a myth that's aerodynamics. Fly a plane slow enough and ANY increase in bank (wing loading) will produce a stall regardless of whether the plane is moving with or against the wind. The myth seems to be that the plane stops flying for some amount of time EVERYTIME it turns crosswind. Just doesn't make sense.
An airplane WILL loose lift in a banked turn if the AOA is not increased with the elevator to match the increase in wing loading. The plane always seeks a balanced energy state. When one thing is changed the plane will seek a balanced state unless something else is done to change it. A plane will start to loose altitude when banked (regardless of wind) because it now needs more airflow over the wing to make up for the increase in load on the wing and will drop it's nose. The PILOT can then stop the loss of altitude by adding elevator input to pick the nose back up. The increased AOA will now require more energy and the plane will slow down. Put in enough bank and the PILOT has to add elevator and power to maintain level flight.
The windtunnel scenario described also doesn't work to prove it. Since the wind in the tunnel moves in one direction and the plane is stationary (front to back even if it can go up and down) in the airflow, turning the stationary plane broadside to the airflow in the tunnel doesn't represent a plane flying through the air. In that case there is no airflow over the wings for lift. It would be like placing the plane on the ground and hitting it with a leaf blower from the side.
Jaybird
Last edited by Jaybird; 01-24-2014 at 08:15 AM.
Who needs headwind anyway. LOL
01-24-2014, 08:06 AM
#1223
There are many "references" that say the chicken came first, others say the egg came first. Neither can prove it, but by your logic, the first one to make a statement is right because no one can prove them wrong. Forgive me if I'm not convinced.
I wish I could build my own wind tunnel, and suspend a model so it can rise or fall freely, then subject it to a 20mph steady wind and trim it out so it is "flying" four or five feet high, then abruptly turn it 90 degrees, then 180 degrees and observe what happens. I'm inclined to believe the model would lose lift and fall. The problem with this is the model has no "inertia" nor is it free to accelerate once turned down wind. But I'm inclined to believe that even if the model was allowed to accelerate after being turned, it would still not accelerate quick enough to avoid losing some altitude.
Maybe someone with a wind tunnel can prove me wrong.
I wish I could build my own wind tunnel, and suspend a model so it can rise or fall freely, then subject it to a 20mph steady wind and trim it out so it is "flying" four or five feet high, then abruptly turn it 90 degrees, then 180 degrees and observe what happens. I'm inclined to believe the model would lose lift and fall. The problem with this is the model has no "inertia" nor is it free to accelerate once turned down wind. But I'm inclined to believe that even if the model was allowed to accelerate after being turned, it would still not accelerate quick enough to avoid losing some altitude.
Maybe someone with a wind tunnel can prove me wrong.
01-24-2014, 08:23 AM
#1224
My Feedback: (57)
I've already done exactly this! I fly UAV's for a living. By nature they navigate via GPS waypoints (ground reference manuvers!) and are very highly instrumented! When turning downwind to final, or upwind to downwind, (our wind limits are 35 kts, which I've flown in many times) there is no change in IAS, ground speed changes of course, but not indicated. Your argument has no credibility. I have telemetry files to back it up.
Once again you are not grasping the issue at hand here, microbursts are NOT steady state wind, which is what this thread is about.
Once again you are not grasping the issue at hand here, microbursts are NOT steady state wind, which is what this thread is about.
Your claim neglects to address the low energy (close to stall) regime of flight. How has the manufacturer come up with the recommended approach speeds for you UAV? Why the buffer above stall?
In order for the original statement of this thread to remain true, you would need to be correct 100% of the time, but in order for it to be discredited, I would only need to be right once.
It is far to definitive of a statement for aviation.
01-24-2014, 08:44 AM
#1225
Here is more proof, I suggest others post links instead of refering to Stick and Rudder or FAA manuals.
http://www.examiner.com/article/myth...nd-too-quickly
http://www.examiner.com/article/myth...nd-too-quickly