I try not to look at the ground at all on windy days. Just watch the plane. The plane doesn't care about the wind, but you can be mislead by relative speeds. Fly in the air, land on the ground. The relative speeds may be significantly different!
Most of all of us fly real airplanes. You are probably seated in your craft.
;)
can guarantee you that wind
Most of all of us fly real airplanes. You are probably seated in your craft.
;)
can guarantee you that wind
Gentlemen (and any ladies present), It is my belief that as the aircraft was turning downwind that the relative airflow over the left wing was reduced because the pilot did not increase the airspeed of the aircraft to account for the relative wind. Because he did not increase the power and therefore the airspeed, the relative airspeed, what pilots would call Indicated Airspeed -had- to have fallen below stalling speed for the wing.
Below is a drawing of what I believed happened. Please correct me if you believe that I am wrong.
Certain assumptions had to be made as to stall speed of the aircraft, and wind velocity. I believe the wind velocity is pretty accurate, based on the wind sock in the crash video.
Your comments, please.
Gary
+-------------------------------------------------------------------+ |Filename: B-52 crash.JPG | |Download:
They are otherwise why would anyone bother to try to take off and/or land into the wind?
The main reason for this is to make the ground speed lower in relation to airspeed so that take off is accomplished sooner and a slower landing speed can mean less damage should the pilot make a mistake.
In some wind conditions, I have managed an almost vertical descent with little, almost no forward speed in relation to the ground.
My two penn'orth FWIW
Malcolm
At #4 you say, "30 knots or so of indicated airspeed will fall off because of the wind that was providing 30 knots of "forward velocity" over the wings". (The downwind turn)
Indicated Airspeed is just that "Indicated". Adding or subtracting airspeed to it is simply wrong. rick
As have most on here, I've heard this argument about the "downwind turn" for years. Essentially I agree with what you say. My classic example helps illustrate it, further convincing me that our perception from the ground is the real culprit. In my case, one day I was flying a bipe, trying to set up for the landing, on the downwind leg. The ~20 mph wind added to the perceived speed in that leg, causing me to mistakenly let its true airspeed drop to just about stall speed, since it was moving relative to me, at what "looked" like plenty of speed. But when I made my turns toward final, it suddenly began losing altitude at a far greater rate than desired. I managed to roll it out level, just as it "pancaked" firmly onto the ground. It caused both wings to buckle, where they were supported in their center mounts, but no other real damage. Just to my ego!! If I'd added some power before beginning the turn, would have been a good landing, HI.
Ol>Therin lies the myth of the downwind turn. Most people fly their plane
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----------------------------------------------------- "Ignorance is treatable, Stupidity is incurable. Sometimes the difference is hardly distinguishable, however."
Crap.
A wing moving against the wind (if any) generates more lift than a wing moving (at the same groundspeed) with the wind. Translation: it's easier to takeoff and land, control -wise, and airspeeds can be slower. Dr.1 Driver "There's a Hun in the sun!"
When I first started flying R/C, I was in such a hurry to get going (I was building a Senior Falcon in the days before CA and five minute epoxy) that I bought a Testors Skyhawk ready-to-fly single channel setup. No throttle or elevator, just a rudder that flapped from side-to-side. Fortunately, when I was in the Air Force and something like this was all I could someday afford, I did a lot of studying on flying single channel R/C, so I had no problems flying it from the start.
The wife and I arrived at the Seabrook, NJ flying field (Misguided Missiles R/C Club - I still have the patch) at about noon (Fall of 1969). There was a high overcast and about a 20 mph steady wind. We fueled up the Skyhawk, fired up the faithful Testors .049 engine and launched it into the wind. I then proceeded to climb at its normal rate, but it never went further than ten feet from where the wife handlaunched it. It ascended to what looked to be about 200 feet when the engine finally burned up all of the fuel. The model then glided to a landing, still within ten or twenty feet of where the model was launched. Everyone applauded as it touched down to another successful landing.
One trick that I picked up from all of that reading was not to turn the model if it made no headway into the wind. You would just have to walk a long way downwind to retrieve it.
Ed Cregger
I'll assume you meant "... and ground speeds can be slower."
Otherwise - Wrong. Airspeeds cannot be slower. If the airplane stalls at
100kts, it will stall at 100kts whether it is flying in a head wind or tail wind or whatever. What matters is the air moving over the surface of the wing, which is generating lift.Landing into a head wind is done to reduce the *ground speed* while landing which results in a shorter landing roll, which requires less of a runway, etc.
Yup, I've had too many of those pucker moments. So many that I seldom reduce the throttle to idle until just above the runway, or, I keep the nose pointed visibly downward. I tend to fly my models to the ground and forsake the full stall landings. I got tired of repairing perfectly good models. I'll do a three point landing on occasion, just to keep my hand at it, but only on calm days.
Ed Cregger
Airplane is traveling straight and level at 80 knots (airspeed) directly into a 20 knot wind. Ground speed is therefore 60 knots. Said airplane executes a 180 degree turn. Throttle was not touched during the turn. Some speed will be lost due to the turn, but assume the turn was gentle and this loss was minimal. The force being exerted by the engine against the air mass is the same after the turn as it was before the turn. According to your picture, at the end of the turn, the plane would only have an airspeed of 60 knots. In fact, the plane would have the same airspeed it had before the turn, 80 knots. The only difference is the ground speed is now 100 knots instead of 60.
This can confuse model pilots because they see the ground speed, not the airspeed. The result is they think their plane is going too fast so they throttle back. They want it to maintain a constant ground speed, which results in changing the airspeed. In this situation, the loss of airspeed is not from the turn, it's from throttling back.
How do I avoid slowing down too much? I keep the throttle at a setting I know is needed to maintain airspeed. I also learn to recognize the signs that indicate I'm approaching stall speed.
Correction! A dead Jack Ass! By the name of D.H.
Am relaxed Ed. Funny thing, I stated several times that I agreed but, no one seemed to bother to notice. Just continue the attack! I also stated in my very first post on the matter that the fault was with the pilot. Oh well! My fault for trying to put something in layman's context with all these self anointed experts here!
Dang! I need to dig out my Kershner's and check this.
Gar
-- GaryMC
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Exactly, another indication is elevator stick position as you fly. Experienced airmen know the feel and relationship between what the airplane is doing in the air and the position of the stick. A "trimmed aircraft feels the same in upwind or downwind conditions. When you need to change the aircraft's position in relation to the ground (or heavy wind turbulence) is where the problems arise. rick
My Model Aircraft Home Page
| > I try not to look at the ground at all on windy days. Just watch the | > plane. The plane doesn't care about the wind, but you can be mislead | > by relative speeds. Fly in the air, land on the ground. The relative | > speeds may be significantly different! | | They are otherwise why would anyone bother to try to take off and/or land | into the wind? | | The main reason for this is to make the ground speed lower in relation to | airspeed so that take off is accomplished sooner and a slower landing speed | can mean less damage should the pilot make a mistake.
There is another reason.
As you get close to the ground, the wind speed generally drops, all the way to almost zero a few inches off the ground. So if you're landing into the wind, your airspeed will drop as you go down even if your ground speed stays the same. This helps the plane stall onto the ground in those last few inches in what is usually considered a perfect landing.
However, if you land downwind, this reduction in wind speed as you go down will actually increase your air speed, causing your plane to take much longer to land, even longer than you'd expect it to after taking into account the wind speed. I've seen people take up the entire runway landing downwind and smacking into the fence at the end because they didn't take this into account. (The only way around it is to use controls to burn up airspeed -- spoilers, crow, slip, etc., or to do a
180 degree turn and land upwind (can be dangerous if you have no power) or to land the plane rather hard (and very fast) and not go for a smooth landing.)| In some wind conditions, I have managed an almost vertical descent with | little, almost no forward speed in relation to the ground.
Be sure to keep it a nice amount above stall speed when you do this. As you descend, your air speed drops (due to the reduction in wind) which is normally fine, but if you're just about at a stall (as you often are when you try to do this) it can easily send your plane smashing into the ground from a few feet up doing lots of damage.
There are days I need to translate. I meant full scale planes. See, FAA certified pilots tend to call models toys and the full scale ones real planes. I have been flying models longer than the full scale things, but still I tend to slip up once in a while when I'm tired, or not paying attention.
Yes, they're all real planes, and IMO both are equally enjoyable. The full scale ones tend to give you a better understanding of what effects the wind and thermals/turbulence has on a plane because you can visually see what's happening in real time.
I like them both.
Want a real rush? Try wake turbulence while on a ASR approach due to partial panel issues! BTDT and it was NOT fun!
If you practice some SERIOUS slow flight AT ALTITUDE, you learn the 'feel' of mush just before it breaks in a stall. For almost all of my landings I pull the throttle before turning base. Of course I usually am WOT until then. . . .
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