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
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.
"There's a Hun in the sun!"
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.
You obviously didn't read exactly what I said or misunderstood. Taking off
and landing into wind means a lower ground speed.
All aircraft have a minimum airspeed at which they can fly. This has
absolutely no relation to ground speed except in totally still air
conditions when airspeed can equal ground speed.
Try to fly a plane of any size more slowly than that airspeed at which the
wing will support the plane's weight will result in a stall.
With sufficient height, the situation can be rectified. With not enough a
crash is the only outcome.
I still maintain that a plane, flying more slowly with respect to the
ground, will suffer less damage than one travelling at a higher ground
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
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.
| > 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
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.
Doug McLaren, email@example.com
Where are we going and why am i in this hand-basket?
OK, hold that same ceiling tile while some guys strap you into a harness
that is attached to a strong rope that is suspended from a hot air balloon.
The guy operating the balloon turns on the propane and the heat causes the
balloon to rise, taking you up into the air with it. What do you feel on the
Answer: Nothing once the balloon is moving along with the prevailing wind.
The same thing happens to a model once it is airborne. Once airborne, there
is no wind.
There will be turbulence caused by ground effects, but they are temporary
and varying in direction.
Now force the balloon to change direction so it's no longer directly with
the wind. Isn't that what a turn does? Isn't that what that B-52 was
attempting to do? As long and relative position in the air mass stays the
same, I agree with you guys. But once the relative position of the plane to
the air mass starts to change, things happen.
Don't factor in ground effect/turbulence into the basic argument, or
everything goes out the window in a hurry. It is called chaos and is quite
capable of reducing our largest computers to blithering idiots in a hurry. I
am not saying that there are not such effects in nature, but they are
separate from the basic issue of relative wind.
When I first began flying models that were capable of flying at extremely
low airspeeds, I ran into a phenomenon that I had never encountered before.
I could be flying along at minimum sustainable airspeed, dead into the wind,
and suddenly the model would simply fall out of the air. Fortunately, I was
usually dragging the model around at one or two feet off of the ground when
this happened, so there was usually no damage.
It then occurred to me on several occasions that just before my model fell
and when I was directly upwind of the model, I had felt a swirl (vortice) of
air go by my body. The model ran into the downwind side of the vortice, the
wing ceased to fly and the model fell to the ground. I was astounded. I had
been flying R/C for well over twenty years and had never encountered this
phenomenon with a conventional model. Why? Because conventional models fly
so fast, relatively speaking, that the effect was unnoticable.
Remember thre downwind fish? Thought so.
Unless an airfoil has eyes, it is blissfully ignorant of which
direction it is proceding relative to the ground. Upwind, downwind,
crosswind it moves with the airmass. UNLESS the airmass changes
direction or speed so rapidly that the inertia of the aircraft
prevents it from matching it instantaineously. This phenomanon is
called windsheer and it has killed quite a few experienced pilots.
While the above accidents were on take-off or landing, it also happens
at altitude. The book "Anvil of the Gods" relates an incident in
which a 707 over Florida in the early '60s was penetrating a
thunderstorm at FL 350 and got flipped on it's back, split-s'd out of
it and landed with an additional 10 degrees dihedral in it's wings.
That forces the question of whether or not that B-52 was above ground effect
or not? Not the models ground effect but the ground effect of the trees,
houses and other obsticals in the area. And that is my point. The air mass
was not static nor was the relationship between the model and the air mass.
The formulas are great for the minute slice of time they describe. But that
moment is quickly gone and new values come into play.
No, it wasn't your point. It may be NOW as you become aware of how
stupid you have made yourself appear, but back then you were all in
favour of wind, pure and simple. No mention of turbulence, wind shear or
You twist faster than greased weasel shit on a politicians trouser bottom.
Yes, we do have to consider turbulence. But I was countering your example
with the ceiling tile, remember? The ceiling tile demonstrated steady wind
from a ground perspective. However, if one holds the ceiling tile long
enough, some turbulence will probably display itself too.
The B-52 in the video I saw entered a classic spiral dive. This is probably
the number one killer of all model airplanes and even quite a few full size
airplanes, I suspect.
My wife's first R/C rig was a used 1968 Micro Avionics four channel
proportional rig. We bought it mounted in a built and ready-to-fly Andrews
A-Ray trainer with a brand new OS Max .35 R/C engine in the nose. This was
in 1970, approximately. We flew it most of the summer before something went
askew, the rudder went full to one side and the model spiraled into the
ground. There was no stopping it. The R/C system had quit working.
In those days, we used five wire servos and battery packs. When one side let
go, the rudder, aileron and any other servo in the system would go hard to
full stop one way or another. The good side was that you didn't have to walk
that far to collect the pieces, unlike today's systems which will die near
After another year of having the system repaired repeatedly, only to pull
the same trick over and over again, I was getting really familiar with the
spiral dive of death. That looks exactly like what happened to the B-52,
although there isn't really any way to verify what was the cause. Mechanical
failure? Maybe. Something could have come unplugged. This is one reason that
I hate plug-in wings. There's simply too much to go wrong in a complicated
model. But how else could one transport a 27' wingspanned behemoth?
Getting one's left and right crossed up during flight will often produce the
same spiral dive. I didn't see any evidence of wind shear or dumb thumbs,
but the crossing up of left and right is still possible.
The truth of the matter is, we most likely will never really know what
caused the crash. Personally, I wouldn't have flown that kind of model in
that much wind. Then again, I wouldn't have flown that kind of model at all
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