Downwind turn Myth
11-23-2010, 06:44 PM
#251
Senior Member
RE: Downwind turn Myth
Free flight models don't accelerate at all when gliding in their circles.
How can that be?
They go "upwind", "crosswind", "downwind", "crosswind", "upwind"... until they fall out of the thermal or the dethermalizer kicks in.
How can that be?
They go "upwind", "crosswind", "downwind", "crosswind", "upwind"... until they fall out of the thermal or the dethermalizer kicks in.
11-23-2010, 06:49 PM
#252
RE: Downwind turn Myth
ORIGINAL: highhorse
No. But if there were, it would be exactly as useful for upwind turns.
ORIGINAL: Taurus Flyer
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Cees
11-23-2010, 06:50 PM
#253
Senior Member
RE: Downwind turn Myth
ORIGINAL: highhorse
What you don't realize is that these are David's own BRITISH pelicans. As with all things British, these pelicans (as opposed to the lowly North American varieties) were not only the first to fly, they are also the most finely engineered and highly evolved of the lot.
What you don't realize is that these are David's own BRITISH pelicans. As with all things British, these pelicans (as opposed to the lowly North American varieties) were not only the first to fly, they are also the most finely engineered and highly evolved of the lot.
But every part that fell off was of the finest British craftsmanship... or is that the Rolls Royce Silver Shadow?
11-23-2010, 06:50 PM
#254
RE: Downwind turn Myth
ORIGINAL: rcjets_63
The British pelican would leap off the front of the carrier and immediately turn 180 degrees upwind. Most of them would be then run over by the ship. The Super Pelican would avoid the ship and survive to fight another day. The Aussie pelican would take a walkabout down the deck and, assuming he wasn't run over by a jet or captured by a Navy cook, would leap off the stern and hold an upwind course. A Canadian pelican wouldn't be there in the first place as we don't have aircraft carriers. A German pelican would fly to the neighboring ship. A French pelican would surrender.
I hope that helps,
Jim
ORIGINAL: roger.alli
Imagine an aircraft carrier at sea traveling at 20 knots, (constant direction, constant speed.) Also imagine there is a 20 knot wind blowing at exactly the same speed and direction as the carrier is traveling. The wind speed/direction on the deck of the carrier will be zero knots. Now, imagine we were to fly a model airplane from the carriers deck, and we fly nice rectangular circuits.
From our point of view, standing on the carriers deck, we would take off, circuit, and land in WHAT WE SEE, as still air. And we would control the plane accordingly.
HOWEVER it has to be conceded, that the model is flying in a wind that is blowing at 20 knots.
So, the million dollar question is::: Will the model, which is flying in 20 knots of breeze, zoom in up wind turns, and sag in down winds turns?
I think I know the answer, but it appears that many here may not.
I hope this helps some see the logic..
Roger
P S I think this would apply to Pelicans (who are magnificent aviators) as well as marginally powered helis, that might operate fly from this carriers deck..
Imagine an aircraft carrier at sea traveling at 20 knots, (constant direction, constant speed.) Also imagine there is a 20 knot wind blowing at exactly the same speed and direction as the carrier is traveling. The wind speed/direction on the deck of the carrier will be zero knots. Now, imagine we were to fly a model airplane from the carriers deck, and we fly nice rectangular circuits.
From our point of view, standing on the carriers deck, we would take off, circuit, and land in WHAT WE SEE, as still air. And we would control the plane accordingly.
HOWEVER it has to be conceded, that the model is flying in a wind that is blowing at 20 knots.
So, the million dollar question is::: Will the model, which is flying in 20 knots of breeze, zoom in up wind turns, and sag in down winds turns?
I think I know the answer, but it appears that many here may not.
I hope this helps some see the logic..
Roger
P S I think this would apply to Pelicans (who are magnificent aviators) as well as marginally powered helis, that might operate fly from this carriers deck..
I hope that helps,
Jim
You forgot to mention that the German pelican would poop-bomb the other ship, that the italian pelican can't make up it's mind way to fly, or to give the Brit pelican credit for the angled deck.
11-23-2010, 06:51 PM
#255
Senior Member
RE: Downwind turn Myth
ORIGINAL: Taurus Flyer
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Experience is the only safety net.
11-23-2010, 06:52 PM
#257
My Feedback: (9)
Join Date: Mar 2002
Location: Mesa,
AZ
Posts: 427
Likes: 0
Received 0 Likes
on
0 Posts
RE: Downwind turn Myth
So is it possible for the guy in the balloon to feel a breeze, a gust, a draft, a puff, anything?
If the answer is no - Than the myth is a myth and everything in the air moves with the air, period.
If the answer is yes - Than it's not a myth, objects in the air are subject to - take your pick- inertia, momentum, acceleration (or the lack of it). Big ***** balloons must take a while to recover from sudden wind changes. Conversely tiny little RC planes must take a while to recover from sudden direction changes (in relation to the "wind").
The answer is yes. And I'm right because I have 100,000 hours in the Jupiter 2 and I breed aerobatic show pelicans. So there...
11-23-2010, 06:53 PM
#258
RE: Downwind turn Myth
ORIGINAL: Taurus Flyer
Planes do stall in downwind turns as explained by several people and that's true, that's the myth I believe,
Cees
ORIGINAL: highhorse
No. But if there were, it would be exactly as useful for upwind turns.
ORIGINAL: Taurus Flyer
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Cees
Knock urself out.
11-23-2010, 06:54 PM
#259
Senior Member
RE: Downwind turn Myth
ORIGINAL: p51Dpony
Cripes-A-Mighty, people can make wrong conclusions. In my examples ''a plane stalling at the top of a loop'' wasn't me struggling to control a plane in wind, it was part of an experiment where 3/4 throttle + 3/4 up elevator into the wind and the plane would loop, while the same throttle + same elevator downwind failed to produce a loop. I already know what camp I'm in, now pretend for a second that this was an unanswerable question, we have one side explaining what they see and they propose a mechanism to explain things, and they are NO LESS experienced or educated than the next camp, the next camp is also presumably educated and experienced, but they claim lack of skill, lack of education, lack of experience, etc ad nauseum towards anyone who doesn't agree with them. Happy Thanksgiving everyone, I need to go do something constructive.
Cripes-A-Mighty, people can make wrong conclusions. In my examples ''a plane stalling at the top of a loop'' wasn't me struggling to control a plane in wind, it was part of an experiment where 3/4 throttle + 3/4 up elevator into the wind and the plane would loop, while the same throttle + same elevator downwind failed to produce a loop. I already know what camp I'm in, now pretend for a second that this was an unanswerable question, we have one side explaining what they see and they propose a mechanism to explain things, and they are NO LESS experienced or educated than the next camp, the next camp is also presumably educated and experienced, but they claim lack of skill, lack of education, lack of experience, etc ad nauseum towards anyone who doesn't agree with them. Happy Thanksgiving everyone, I need to go do something constructive.
11-23-2010, 06:55 PM
#260
RE: Downwind turn Myth
ORIGINAL: Tall Paul
.
Experience is the only safety net.
ORIGINAL: Taurus Flyer
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Gents,
I am interested in your “mythâ€, and I often see there are very valuable jets on internet, my question is: “Is there any stall alarm system you jet pilots use?†or do anyone of you use another method to prevent stall in downwind turns?
Cees
Experience is the only safety net.
When you think so you are not experienced enough!
Cees
11-23-2010, 06:57 PM
#261
RE: Downwind turn Myth
ORIGINAL: edh13
So is it possible for the guy in the balloon to feel a breeze, a gust, a draft, a puff, anything?
If the answer is no - Than the myth is a myth and everything in the air moves with the air, period.
If the answer is yes - Than it's not a myth, objects in the air are subject to - take your pick- inertia, momentum, acceleration (or the lack of it). Big ***** balloons must take a while to recover from sudden wind changes. Conversely tiny little RC planes must take a while to recover from sudden direction changes (in relation to the ''wind'').
The answer is yes. And I'm right because I have 100,000 hours in the Jupiter 2 and I breed aerobatic show pelicans. So there...
So is it possible for the guy in the balloon to feel a breeze, a gust, a draft, a puff, anything?
If the answer is no - Than the myth is a myth and everything in the air moves with the air, period.
If the answer is yes - Than it's not a myth, objects in the air are subject to - take your pick- inertia, momentum, acceleration (or the lack of it). Big ***** balloons must take a while to recover from sudden wind changes. Conversely tiny little RC planes must take a while to recover from sudden direction changes (in relation to the ''wind'').
The answer is yes. And I'm right because I have 100,000 hours in the Jupiter 2 and I breed aerobatic show pelicans. So there...
The subject wind is STEADY STATE and there will be nothing felt in the basket.
Yes, there are puffs, but they can come from ANY direction and are not the same as steady state winds at all, are not the subject of this thread or of the myth. U are answering some whole other question (puffs, windshear etc) that no one is debating and are confusing apples with oranges.
11-23-2010, 06:59 PM
#263
RE: Downwind turn Myth
ORIGINAL: highhorse
Yes, there are puffs, but they can come from ANY direction and are not the subject of this thread or of the myth.
ORIGINAL: edh13
The answer is yes. And I'm right because I have 100,000 hours in the Jupiter 2 and I breed aerobatic show pelicans. So there...
The answer is yes. And I'm right because I have 100,000 hours in the Jupiter 2 and I breed aerobatic show pelicans. So there...
Get with it people!!!
Jim
11-23-2010, 07:07 PM
#266
RE: Downwind turn Myth
ORIGINAL: rjbob
Weren't British Pelicans the first to be pressurized?
Weren't British Pelicans the first to be pressurized?
Alas, we digress and should return to the topic.......
11-23-2010, 07:09 PM
#267
RE: Downwind turn Myth
ORIGINAL: dubd
This has turned into one of the most informative threads that I've seen on RCU. It's been interesting to read about the science behind the topic.
This has turned into one of the most informative threads that I've seen on RCU. It's been interesting to read about the science behind the topic.
We live in 2010, so it is no science, RC modeling is more than 50 years old , we have 2,4 GHz computer radio's and do fly with 199.99 Mph.
Don't try me to believe the jet flyers do not have any stall alarm!
Cees
11-23-2010, 07:11 PM
#268
RE: Downwind turn Myth
ORIGINAL: Taurus Flyer
We live in 2010, so it is no science, RC modeling is more than 50 years old , we have 2,4 GHz computer radio's and do fly with 199.99 Mph.
Don't try me to believe the jet flyers do not have any stall alarm!
Cees
ORIGINAL: dubd
This has turned into one of the most informative threads that I've seen on RCU. It's been interesting to read about the science behind the topic.
This has turned into one of the most informative threads that I've seen on RCU. It's been interesting to read about the science behind the topic.
We live in 2010, so it is no science, RC modeling is more than 50 years old , we have 2,4 GHz computer radio's and do fly with 199.99 Mph.
Don't try me to believe the jet flyers do not have any stall alarm!
Cees
11-23-2010, 07:13 PM
#269
RE: Downwind turn Myth
ORIGINAL: highhorse
OK, the jet flyers have stall alarm. I was lying, but you caught me, there, Sherlock.
ORIGINAL: Taurus Flyer
We live in 2010, so it is no science, RC modeling is more than 50 years old , we have 2,4 GHz computer radio's and do fly with 199.99 Mph.
Don't try me to believe the jet flyers do not have any stall alarm!
Cees
ORIGINAL: dubd
This has turned into one of the most informative threads that I've seen on RCU. It's been interesting to read about the science behind the topic.
This has turned into one of the most informative threads that I've seen on RCU. It's been interesting to read about the science behind the topic.
We live in 2010, so it is no science, RC modeling is more than 50 years old , we have 2,4 GHz computer radio's and do fly with 199.99 Mph.
Don't try me to believe the jet flyers do not have any stall alarm!
Cees
Tell your other jet pilots about the system to destroy that "myth".
Cees
11-23-2010, 07:21 PM
#271
RE: Downwind turn Myth
ORIGINAL: highhorse
Really? You don't say !
I am not Sherlock Holmes, he was an Englishman.
Cees
11-23-2010, 07:22 PM
#272
RE: Downwind turn Myth
ORIGINAL: Lnewqban
The attached diagram (copied from http://www.aeroexperiments.org/introcircles.shtml) is the flight path that I see from the ground while you control the airplane from the basket.
The higher the speed of the wind and of your ''world'' drift, the more deformed I see it.
Note that the red vector pointing to the basket at each instant does not change magnitude.
That vector is the centripetal force (or centripetal acceleration x mass of the plane), which is the force that you are stealing from the vertical lift to make the plane turn.
The attached diagram (copied from http://www.aeroexperiments.org/introcircles.shtml) is the flight path that I see from the ground while you control the airplane from the basket.
The higher the speed of the wind and of your ''world'' drift, the more deformed I see it.
Note that the red vector pointing to the basket at each instant does not change magnitude.
That vector is the centripetal force (or centripetal acceleration x mass of the plane), which is the force that you are stealing from the vertical lift to make the plane turn.
Interesting; I've been following this thread since the begining and have seen some very accurate and some wildly crazy logic.
So, The winds being 15-18mph here in Charlotte today and 25-30mph @ 5000ft I decided to take the 172 Cessna out for an experiment. Went south from Rock Hill, SC till I was out of the CLT/Douglas IAP controlled airspace then began doing several co-ordinated 2 minute turns over a stretch of highway that was running near dead-on the wind direction. I kept my eyes inside and concentrated on the instuments and keeping the plane trimmed and and the manuever true. My spotter observed the resulting flight path...amazingly it looked just like Lnewqban's drawing above!! Also, my indicated airspeed was 100kts throughout the maneuver and didn't require any power setting changes nor attitude changes to maintain +/- 50 ft from the entry altitude the whole time. As I expected; the airplane had no idea whether it was headed upwind, downwind or crosswind.
In a moving airmass it's all the same in relation to the airmass...only differs in relation to the ground.
Just for grins and giggles we then picked out a likely ground reference (a nice silo) and did a few "turns-around-a-point". This was a great excercise in co-ordinating angle of bank, trim, thottle control, attitude control and evrything else! When upwind of the silo we were barely at a 10* angle of bank to keep from drifting closer and when downwind we were nearly aerobatic to keep from drifting away.
Next was a manuever I never really tried before in a full scale since there was never any reason to. That was a 'turn-around-a-point" while maintaining altitude and trying to maintain relative ground speed(best as we could visually determine) Figured that this would most closely simulate how a pilot on the ground would "want" to see the turn if he were executing it from the ground. After riding the stall horn for a moment we decided that this was a manuever we should probably not pursue.
For what it's worth, it was a fun day boring holes in the sky and annoying some hapless farmer.
Cheers!!
11-23-2010, 07:35 PM
#274
RE: Downwind turn Myth
ORIGINAL: frets24
Interesting; I've been following this thread since the begining and have seen some very accurate and some wildly crazy logic. So, The winds being 15-18mph here in Charlotte today and 25-30mph @ 5000ft I decided to take the 172 Cessna out for an experiment. Went south from Rock Hill, SC till I was out of the CLT/Douglas IAP controlled airspace then began doing several co-ordinated 2 minute turns over a stretch of highway that was running near dead-on the wind direction.
I kept my eyes inside and concentrated on the instuments and keeping the plane trimmed and and the manuever true. My spotter observed the resulting flight path...amazingly it looked just like Lnewqban's drawing above!! Also, my indicated airspeed was 100kts throughout the maneuver and didn't require any power setting changes nor attitude changes to maintain +/- 50 ft from the entry altitude the whole time. As I expected; the airplane had no idea whether it was headed upwind, downwind or crosswind.
In a moving airmass it's all the same in relation to the airmass...only differs in relation to the ground.
Just for grins and giggles we then picked out a likely ground reference (a nice silo) and did a few ''turns-around-a-point''. This was a great excercise in co-ordinating angle of bank, trim, thottle control, attitude control and evrything else! When upwind of the silo we were barely at a 10* angle of bank to keep from drifting closer and when downwind we were nearly aerobatic to keep from drifting away.
Next was a manuever I never really tried before in a full scale since there was never any reason to. That was a 'turn-around-a-point'' while maintaining altitude and trying to maintain relative ground speed(best as we could visually determine) Figured that this would most closely simulate how a pilot on the ground would ''want'' to see the turn if he were executing it from the ground. After riding the stall horn for a moment we decided that this was a manuever we should probably not pursue.
For what it's worth, it was a fun day boring holes in the sky and annoying some hapless farmer.
Cheers!!
ORIGINAL: Lnewqban
The attached diagram (copied from http://www.aeroexperiments.org/introcircles.shtml) is the flight path that I see from the ground while you control the airplane from the basket.
The higher the speed of the wind and of your ''world'' drift, the more deformed I see it.
Note that the red vector pointing to the basket at each instant does not change magnitude.
That vector is the centripetal force (or centripetal acceleration x mass of the plane), which is the force that you are stealing from the vertical lift to make the plane turn.
The attached diagram (copied from http://www.aeroexperiments.org/introcircles.shtml) is the flight path that I see from the ground while you control the airplane from the basket.
The higher the speed of the wind and of your ''world'' drift, the more deformed I see it.
Note that the red vector pointing to the basket at each instant does not change magnitude.
That vector is the centripetal force (or centripetal acceleration x mass of the plane), which is the force that you are stealing from the vertical lift to make the plane turn.
Interesting; I've been following this thread since the begining and have seen some very accurate and some wildly crazy logic.
So, The winds being 15-18mph here in Charlotte today and 25-30mph @ 5000ft I decided to take the 172 Cessna out for an experiment. Went south from Rock Hill, SC till I was out of the CLT/Douglas IAP controlled airspace then began doing several co-ordinated 2 minute turns over a stretch of highway that was running near dead-on the wind direction. I kept my eyes inside and concentrated on the instuments and keeping the plane trimmed and and the manuever true. My spotter observed the resulting flight path...amazingly it looked just like Lnewqban's drawing above!! Also, my indicated airspeed was 100kts throughout the maneuver and didn't require any power setting changes nor attitude changes to maintain +/- 50 ft from the entry altitude the whole time. As I expected; the airplane had no idea whether it was headed upwind, downwind or crosswind.
In a moving airmass it's all the same in relation to the airmass...only differs in relation to the ground.
Just for grins and giggles we then picked out a likely ground reference (a nice silo) and did a few ''turns-around-a-point''. This was a great excercise in co-ordinating angle of bank, trim, thottle control, attitude control and evrything else! When upwind of the silo we were barely at a 10* angle of bank to keep from drifting closer and when downwind we were nearly aerobatic to keep from drifting away.
Next was a manuever I never really tried before in a full scale since there was never any reason to. That was a 'turn-around-a-point'' while maintaining altitude and trying to maintain relative ground speed(best as we could visually determine) Figured that this would most closely simulate how a pilot on the ground would ''want'' to see the turn if he were executing it from the ground. After riding the stall horn for a moment we decided that this was a manuever we should probably not pursue.
For what it's worth, it was a fun day boring holes in the sky and annoying some hapless farmer.
Cheers!!
BTW...You have a guitar with 24 frets? All of mine only have 22.
11-23-2010, 07:37 PM
#275
RE: Downwind turn Myth
ORIGINAL: highhorse
no scientific observations allowed.
baseless opinions only please.
no scientific observations allowed.
baseless opinions only please.
That's a good point.
I read several posts of pilot observations and IAS.
Model airplanes normally do not have any airspeed indicator so I think it is a good point not to talk about IAS anymore.
We can have a CAS, so that's no problem for me when people do use that expression.
Cees