Avaiojet

It doesn't take much to do slow fly at a safe altitude, if for no other reason, to get a feel of any model at given speeds. Could probably could have prevented the mishap at landing.

In any case, the cause wasn't the weight of the model.

Charles

combatpigg

My Feedback: (3)

The weight of the model is always the cause. I could practically guarantee from where I sit that if that same plane was flying at 1/2 the weight, it would have been much more difficult to stall. The first course of action should be to see where useless weight can be shed, secondly get the plane balanced far enough aft to lower the stall speed.
Anyone can learn how to land a brick, if that's how you want to "do" the hobby.

Edge3644

My 27% Cap 232 has new experimental set of wings. Root 16%, tip 24%. This combination gives constant wing thickness.
The wing may look funny, but as a result Cap is 100% wing tip stall proof. Snap rolls are slower than with std wing (16-12%), but the down line
breaking is really impressive.

pimmnz

And use a bit of caution about the 'balance far enough aft to lower stall speed' bit, it can't. Only weight reduction will lower the stall speed. It works because all wings stall at an angle, and in model sizes it will be 6 to 9 degrees, almost regardless of the wing section. The weight will determine how soon the angle is reached as the airplane is slowed. The cg will determine how effective, or sensitive, the model is to elevator movements. On a tapered wing the tip will usually stall before the root, if only because the smaller chord is less efficient. 'Washing out' the tip helps by delaying the tip stall because its angle to the free stream is now a couple or so degrees less than that of the root. All else being equal the stall across the wing should now occur, if not from the root first, then at least across the whole wing, rather than propagating from the tip inwards. And that is about all there is to it.
Evan, WB #12.

combatpigg

My Feedback: (3)

Let me rephrase it and say that unless the average modeler takes the time to optimize the balance point for the best flare at final, the average model is most likely too nose heavy and will tend to land hot. I've seen this sceanario play out too many times with my own 2 eyes to hear any different. If you try to yank the nose of a nose heavy plane, it's just gonna snap at you.

Ask the payload competition guys if they think that optimizing the CG is important. That's what we're talking about here with a plane that tends to be snappy.

Reducing significant weight might be next to impossible in some cases, I like the idea of building a wing better suited for the intended usage...this is how I like to do the hobby. The other "fixes" are bandaids.

da Rock

Washing out a wing actually reduces the max lift available from that wing.

The weight of the airplane decides how much lift is needed. The wing can produce what it can produce. Make some part of that wing less effective and that amount of lift available is reduced. And the way the wing gets more lift when needed is from more AOA. But reduce the max lift available by reducing the contribution of the tips and the sooner that wing runs out of max lift .

Wash out the wing or build another, if the sucker is a pig, it flies like a pig.

The heirarchy is simple. The weight decides how much lift is needed at the speed you want. The wing provides it by AOA. Increase the weight and more lift is needed so where does the wing find more lift? from more AOA. It's got nothing else to work with. So you either fly faster or build lighter.

The max lift available and the weight of the airplane don't change in flight (unless you can change the wing in flight). Either get more max lift or need less of it, if you want to land at the speed your plane presently stalls at.

Washing out will let you land safer, but it won't be at the present stall speed. But that really isn't going to matter, because none of us can tell the difference in speed that'll result.

vertical grimmace

My Feedback: (1)

When designing a wing, using a thicker section at the tip does help. We even did this with a modern CL combat design to delay the stall.
I would reiterate that weight is the main reason for the needs of a fast landing. I think that the primary poster had a misconception,fear that because his plane had a tapered wing, it would be hard to land. Not true. If it is heavy and warped or not straight, then yes but I doubt that his out of the box stock ARF will be much trouble. Unless he adds so much too it that it gets too heavy.
I have always loved the way a tapered wing flies. One of them being added satbility in yaw. They just track better.

Jezmo

I think dick is on to something here because I fly a CompARF Extra 2X2 and an Aeroworks Extra 260 both with 50cc engines and both have tapered wings and both have the most docile stalls of any plane I own. The common thing between the two is VERY light wing loading. When they stall they just fall straight down with no hint of a wing dropping. (Think elevator, harrier, or parachute here) I also have some foamies that have tapered wings and they have docile stall tendencies as well which leads me to believe it has a lot to do with wing loading as there is absolutely no way the foamy can have any change in wing thickness nor any chance of washout effects. It may have already been mentioned but lateral balance is very important in getting the stall to occur more straight down. If one wing is carrying more weight it will naturally fall (stall) first creating the appearance of a tip stall even if in reality the whole wing stalled all at once. Just my two cents.

brjensen71

My Feedback: (1)

Aileron differential, it is all that is needed to tame the nastiest tip stalls. Most low speed tip stalls on landing happen when aileron is applied to correct the flight attitude and the wing snaps in the opposite direction.

The old school method is to set-up the linkage to give more up than down throw on each wing. A more preferable method is to use a computer radio with individual servo in each aileron. Either use one of the pre-programed differential set-ups or program one of your own.

The most preferred method for an aerobatic model is to use mixes or a condition to selectively turn the aileron differential on and off. I set-up any model that may have tip stall tendencies with selectable differential, 100% up and 0% down when on ( always have the ailerons on high rate when using this much differential). In other words, I only have spoilerons on landing, full function ailerons during flight.

I have been able to tame several nasty Giles 202's. In fact I can slow the plane up, let a wing start to drop, and use aileron to to correct without tip stalling, or more correctly recover from a tip stall. I can mush a plane all the way in for a nice hard landing (and bent landing gear) if I wish. While slowing an airplane that slow is not the best technique for a nice landing, the aileron differential will prevent a poor landing from turning into a disaster. Knowing that it is there and how well it works, it really helps calm me down and concentrate on flying and learning the quirks of a new plane without cracking it up.