Must you always land into the wind? Would a 3-5 MPH wind be much of a problem, if landing with the wind?

I would say no, you would have to go a little faster and it won't have as much lift, I am probably wrong but rought calculations if it is a 5 mph wind you will have to go about 10 mph faster to get the same lift, and on some trainers that can be twice as fast.

I hope that I am not too far wrong []

Let's assume your plane lands at 18 mph in calm wind. If you land into a headwind of 10, your airspeed is still going to be 18mph, but your ground speed (what you see) will be eight mph. Now let's reverse it with the same speeds. Landing with the wind of 10 will give you a ground speed of 28 mph and airspeed of 18 mph. Hope that helps.

Happy Landings!

oops!

You never "have" to do anything. It is simply best too, certainly for a beginner. Try it in a light wind and see how it feels. It will want to stay on the ground and your controls will feel a little numb as well.

You get less lift going with the wind...and sometimes no lift
It becomes a problem sometimes when flairing 3 ' off of the deck and the model just drops

when it's a dead stick.. sometimes you don't have the option of going around

For me..it's like landing a brick hot when going with the wind, speed but less lift.

Once you try it, and see how long it takes to either land, or put it down hard, you will probably end up using the little flag on the end of your transmitter (unless you are 2.7 ghz) to tell which way the breeze is blowing, and land into the wind. 3 to 5 miles an hour, you will be able to land, but you will use up about 50% more runway doing it.

You can land down wind, but you have to be very careful that you don't overshoot the runway. The only time I do a down wind is if I'm dead stick and that is my only option. Figure a 5mph head wind and you are landing at 10MPH ground speed. Air speed of 15mph. Turn it around, and add the wind to the air speed to get ground speed, now at at ground speed of 20mph. The problem is that you judge your landing speed in relation to the ground, You sense you are going to fast and you keep cutting throttle to slow down. To get down to the 10mph ground speed you are used to, your air speed is going to be down to 10mph and that my be enough for a full stall. If a gust hits, you can be in big trouble. Remember that the wind is not a constant, but variable in both direction and speed. You have to have enough air speed and momentum to handle the changes.

I've seen a couple very seasoned flyers drop their plane landing up wind . On one ocasion, the wind was just about steady 15mph straight down the runway. The guy was flying a 3D and it was hovvering into the wind and slowly loosing altitude. He was down to about 10 ft when the wind just quit for a second. He had no momentum and was suddenly at an air speed of zero. He picked up the parts. The same thing can happen with a gust when landing down wind.

Don

Three things to consider with a downwind landing. Airspeed of the plane, groundspeed of the plane, and stall speed of the plane.
Airspeed is what keeps it flying, so less lift downwind is not correct. You have to have an airspeed greater than the stall speed to keep flying, and if you're flying downwind, that means a greater groundspeed. The math above, adding the wind speed to the airspeed of the plane is correct insofar as it increases the ground speed, and therefore you'll touch down a lot faster coming in downwind. Not a bad thing to practice on occasion, as sometimes you'll have no options except a downwind approach. Same as practicing for crosswind landings. Get good and comfortable with upwind or no wind landings first, though.

Well, if you're flying, at some point you HAVE to land.

Now can less lift going down wind be incorrect ?
think about it for a minute.

Havn't you seen trash blowing in the wind,
it's floating in/with the wind but it's not control flight.

You can piont a model into a 15-20 mile head wind..if you're good
and just hover....no air speed ,but plenty of lift.

How do you think i make my heli hover without going into forward flight ???
sometimes with negative air speed or reverse.lol

Think about it...you flew a kite at some piont in you life....no air speed
You've probably lost a kite becuase the string broke...
Dose the kite still retain lift as it floats away with the wind ? plenty of air speed in a stall...lol

Incorrect. If you hover a model in a 20 mile per hour head wind your airspeed is 20 miles per hour, your groundspeed would be zero. Lift production relies solely on airspeed, not groundspeed.

Helicopters are a completely different animal and can't really be compared to this situation.

Truth is, you don't have any less lift going down wind, but your groundspeed will be increased. Think about this, on a calm day and airplane is traveling at 20 miles per hour on final approach. In this situation airspeed and groundspeed are both 20 miles per hour. Now you have a ten mile per hour headwind component on final. Now if your airspeed is going to be 20 mph your groundspeed will be 10 mph. You will perceive the airplane going half as fast; however, the airplane is actually flying through the air at the same speed. Finally, imagine a five mile per hour tailwind component. To get your 20 mph airspeed on approach your groundspeed will be 25 mph. You appear to be going faster (and you are - across the ground at least), but your airplane controls the same. Therefore, if a pilot flies downwind at a speed that looks the same as on a calm day they will be 'X' airspeed closer to a stall, where 'X' is the tailwind component.

FACT: Airplanes don't care about wind and don't fly with reference with the ground. The only reason we use the ground for reference is because our earthbound caveman brains think that way (after all, air is invisible and it is difficult to think within that frame of reference), and for landings when you need to hit a certain spot on the ground at a certain speed.

Sure you have airspeed, it's the "15-20 mile headwind" passing over the wings. the plane might not have any ground speed, since it's not moving relative to where you're standing.
In this case, the thrust from the rotor is called lift, as it is the force opposing gravity. Same if you're hovering a 3-D plane
The kite is in "tethered flight" since it is restrained from moving relative to the ground (except for 'up'), but the breeze you're flying the kite in is the airspeed making it fly. When the string breaks, th wind surely carries it away, like the trash you mentioned, and as long as the wind is strong enough to overcome the weight of the kite, it will stay aloft, but I wouldn't call it "flight"

Nathhan is correct. It's all about air speed. And momentum. It takes a bit for a plane to catch up with a change in wind. Either the planes airspeed increases and it lifts because suddenly the air speed jumps, or suddenly the air speed decreases and it drops. I've had a number of old timers at the field say "the plane doesn't know which wasy the wind is blowing" B.S. It effects full scale planes and our models are no different. If you have enough air speed and enough momentum, a change in wind speed or direction is going to bump you around. If your air speed and momentum is to slow, pick up the pieces.

If you are flying slow enough that the sudden change in air speed, due to a change in wind speed or direction, drops our air speed below the stall speed, you are in trouble. If you are a few hundred feet above the ground, you get tossed around a little. If you are a few feet off the ground, well then you may have a problem.

Don

That last i check lift is lift..

that thing call a rotor ...is a wing...

that thing mounted on the front of your model that you call a prop is a wing

okay...why do you take off up wind instead of down wind ?

why dose it take longer for the model to lift off of the ground when taking off down wind ?

and how come your model wants to gain altitude when flying into a head wind ?

Not to offend you but.....

Look in a physics book... you are wrong and giving mis-information.
Also Helis and Airplanes are 2 completely different methods of flight and really cannot be compared in most aspects. Wind speed does affect heli's, but in a much different way.

-Yes the rotor is a wing what creates lift with rotor speed which translates to air speed moving over the blades... no power = no lift, no forward motion required. You can fly a heli with no ground speed because it is the rotor speed that translate into lift.

-The prop is more or less an airfoil, but if you want to call it anything it is an airscrew... By it's plane of motion and design the prop creates thrust, not lift. The engine turns the prop, the thrust of the prop pulls the plane, thus creating airspeed over the wing which translates into lift.

-If you take off up wind, ground speed (+) wind speed equal more air speed which translates into more lift on the wing. This means your take off takes less distance to gain flying air speed over the wing.

-If you take off down wind, ground speed (-) wind speed equal less air speed which translates into less lift on the wing. This means your ground speed must be higher to overcome the wind speed to create lift (you are staring with a wind speed that is actually negaitve). So it takes a lot more distance to get the wing to flying air speed.

-The model wants to gain altitude bcause of air speed, not ground speed. The wind speed over the wing increases lift when added to the ground speed (same as on take off) and translate to more air speed, not ground speed.

Just do some reseach online, this is by no means a new science and it really is not a complicated as people make it in their minds... Just the Caveman in us all I guess.

mmm how do you think a heli gose into forward flight ?

exactly....less air speed when going with the wind.

That last I check...less wind blowning the wing = less lift

so when you think...that some how landing with the wind won't generate less lift
just becuase you see the model flying pass you...relative to the ground.
When it drops and smack into the ground at decent ground speed..you'll know what I'm talking about.
becuase you're first instink is to pull up on the stick to slow it down.

I mean if there wasn't wind blowning in front of the wing in the same direction...it wound makesense like you're
saying.

it's the samething when you flip a penny into the air while sitting in a car...the penny dosn't smack you in the
face when the automobile move forward. it moves with the car.

The same happens when your model is in a pocket of wind


think about it for a minute

like i said...it's like landing a brick hot

Airspeed and ground speed are completely independent. Wind will either increase your airspeed or decrease depending on whether you are flying into it or with it. Flying 30mph with a 10mph wind, your airspeed is 20mph. 30mph into a 10 mph wind your airspeed is 40mph. It is all relative to the airflow that your wings are experiencing.

Yes because your airspeed has decreased. If you are flying into it, then the more wind blowing = increased airpseed = increased lift.

The penny has 0 airspeed, but the ground speed is equal to the speed of the car. So when this relates to you plane in a pocket of wind, you had better hope that you are flying faster than the wind above stall speed, or your plane will fall out of the sky because 0 airspeed = 0 lift. Similiar to the penny falling back into your hand.

Flip the penny outside the window and its airspeed and ground speed are equal to the speed of the car.

By tilting it's lift vector.

This is one reason helis are relatively unaffected by local winds. The lift vector of the rotors gets "angled" to transform a part of it into a motion vector.

The heli itself doesn't CARE if this is forward, reverse or sideways, as it can tilt the plane in any direction the pilot chooses.

A heli goes into forward flight by altering the rotor blades path and pitch (assuming this is CCP), but this is NOT what we are talking about here...

Yes, less wind speed over the wing will generate less lift in all cases. In order to create more lift the groundspeed will increase. I am not saying that landing with the wind does not generate less lift... I am saying that it will require more groundspeed coming in resulting in a fast landing and a long roll out - the "Hot Brick". If you try to slow the plane down to what looks like normal landing speed you will most likely stall and find your airplane has become splinters. This is why I recommend a beginner take off land into the wind at all times because they don't really have the skill developed to feel and react to the airplane.

The penny idea relates more to inertia... not air speed.

C'mon guys. This flyX guy can't REALLY believe the crap he's spouting. ALMOST nobody is that completely wrong without trying to be.

Actually what you are saying here is not true, because you're still mixing ground speed and wind speed.

In your example of flying 30mph into a 30mph wind you said "ground speed is 0 but your airspeed is 60mph." If your GROUND SPEED is zero, your plane is seeing the same 30mph wind that you are experiencing standing still on the flight line. It CAN'T be seeing a 60 mph wind because it's not moving relative to the ground. It's the same 30mph wind that you have blowing into your face. Only if the plane has a ground speed of 30mph directly into a 30mph wind will it have an airspeed of 60mph.

You have it right above that when you say "30mph into a 10mph wind your airspeed is 40mph." This is true, but only because your GROUND SPEED is 30mph. When your ground speed is 0, the plane would be seeing only a 10mph wind.

Look at it this way. If your plane stalls at an airspeed of 20mph it will just barely hover (0 ground speed) in a 20mph wind. It won't hover in an 18mph wind. On the other hand, in a 25mph wind the plane will hover, but you'll have to add power to bring it's airspeed to 25mph, vs the 20mph above. If you don't add the power the plane will actually be moving BACKWARDS relative to you on the ground. It will be flying at it's stall speed of 20mph, moving backwards vs the ground at 5mph.

Bob

A side issue but I found it interesting, I am sure that I don't have it completly correct, but close. In the end of WW2 when B29's were flying to Japan, they were having all kinds of problems at high altitudes, apperantly they did not fully understand the jet stream and how much it effected their ground speed, the plane indictated that they were flying 200 some knots but the bombadier was only indictating slow ground speed, it messed everything up.

Yes I realize my mistake. Sometimes it is easier to just know something rather than trying to explain it! Thanks

Not surprising as they didn't have the meteorology and satellite data we have these days. And the Japanese weren't helping much by providing data either.