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Ail & Rud settings to slow landing by crabbing

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Ail & Rud settings to slow landing by crabbing

Old 12-29-2015, 01:26 PM
  #26  
speedracerntrixie
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Originally Posted by Charlie P.
I wouldn't say abandon it. It's a viable technique for cross wind landings if they can't be avoided. I just don't think it can be a mix. Kind of had to be adapted to conditions.

But for the basics stick with taking off and landing into the wind.

Later we'll work on crabbing and then the knife-edge approach to lose altitude. ;-)
yes but, the airplane has to be set up correctly otherwise this becomes much more difficult.
Old 12-30-2015, 09:50 AM
  #27  
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Oh, I agree. Nothing worse than trying to crab in a model with the ailerons reversed. ;-)
Old 12-30-2015, 10:19 AM
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Originally Posted by Charlie P.
Oh, I agree. Nothing worse than trying to crab in a model with the ailerons reversed. ;-)

LOL almost lost my coffee on that one but I think you know what I ment. How many times did we read a model review that read " just a couple clicks of right and one click down and it trimmed out perfectly"? Worse yet, how many guys bought into that crap? Some of us know there is much more to getting an airplane flying really well then just pushing the trims a few clicks. Ever wonder why one guy will rave about a certain airplane while another dogs the exact same design? It's all in the setup and trimming. Yet IMO it's the most difficult thing to get across to guys. Just like this thread, I provided the answer early on concerning why this particular airplane doesn't like to slow down. It's just not set up correctly, the CG is too far forward. Sure it could be helped with some refining of technique and a prop with less bite but the airplane is still going to be nose heavy and fly poorly over the entire envelope because of it.

If we were to beleive some people, one would think it impossible for me to land my 40% Extra simply because it has unlimited vertical and runs a 30X13 prop, oh my how do I slow it down enough to land? LOL
Old 12-30-2015, 11:14 AM
  #29  
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Yes sir.

I'm old school enough that I try not to use sub trims when installing the linkages. I still remember before computer transmitters when there were no model memories, so if you had more than one model they HAD to be neutral when powered up.
Old 12-30-2015, 05:04 PM
  #30  
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Originally Posted by speedracerntrixie

If we were to beleive some people, one would think it impossible for me to land my 40% Extra simply because it has unlimited vertical and runs a 30X13 prop, oh my how do I slow it down enough to land? LOL
Sorry you seem to think the discussion that tried to convince the OP to expand his landing skills were aimed at you. It really isn't about you at all.

I would have suggested to him a couple of ways to judge how nose heavy his plane is, but it looked like you'd offer that help.

It would be interesting to see how the OP got that foamy nose heavy and how much it is. Foamies usually don't have any options at all about equipment placement which is usually the cause when a CG is off. Looking at the Ripmax site it looks like it's a typical foam-e with a somewhat limited battery compartment.

It actually does make sense to offer the OP some suggestions on learning to slow a model down to land.

Last edited by da Rock; 12-30-2015 at 05:20 PM.
Old 12-30-2015, 06:19 PM
  #31  
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Originally Posted by da Rock
Sorry you seem to think the discussion that tried to convince the OP to expand his landing skills were aimed at you. It really isn't about you at all.

I would have suggested to him a couple of ways to judge how nose heavy his plane is, but it looked like you'd offer that help.

It would be interesting to see how the OP got that foamy nose heavy and how much it is. Foamies usually don't have any options at all about equipment placement which is usually the cause when a CG is off. Looking at the Ripmax site it looks like it's a typical foam-e with a somewhat limited battery compartment.

It actually does make sense to offer the OP some suggestions on learning to slow a model down to land.

Correct, it was about the OP, that's why we should strive to give him the best advise we can even if we don't agree. We all have different experiences, why not let him benifit from them all?
Old 01-02-2016, 06:20 AM
  #32  
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hi LuckyPat, hope the new year starts off with that AcroWat flying better.

It seems nobody is going to follow up on the nose heavy advice. Experienced flyers usually know how to flight trim that, so for the less experienced, flight trimming it is among the most simple of the trims.

There are at least 3 methods. They all start with a model you've got trimmed to fly level and steady.

The simplest of the three is to simply roll the plane inverted and judge how much elevator you need to continue at the same altitude. If the model is nose heavy, you had to trim some up elevator to get level upright flight. You will have been flying around with your horizontal tail "pushing down" to lift up the extra nose weight. When you rolled inverted, that trim setting causes the plane to pitch toward the ground and you've got to provide opposite elevator to keep the plane flying level. If you need to hold much elevator to hold level when inverted, the plane is nose heavy. The AWot looks like it's got a symmetrical airfoil and is a mid-wing, so it ought not require any significant elevator to fly level inverted.

The other two tests are easier for most inexperienced flyers. Both start like the first, from normal, level cruise. One is to pull up about 45degrees, the other to dive about the same.

To do a climb test, point the nose up and watch the pitch as the plane slows in the climb. The idea is that as the plane climbs, it will slow down and the pitch trim for level flight will get less effective as the speed erodes. With a plane as you describe that has greatly excessive power, it probably would be smartest to enter the level part before the pitch up at about half it's top speed and don't touch the throttle at all in the test.

To do a dive test, most flyers pull off the power, pitch it down and then watch how straight the model tracks. It should follow a fairly straight line. This test doesn't work well for fast, slick airplanes since they don't slow down. Probably not the best to use with the AWot.
Old 01-02-2016, 06:33 AM
  #33  
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All three of those tests rely on the plane slowing down. All three are done with the expectation the tail will not be able to carry the excess nose weight as the airflow over the tail loses speed. The expectation is you've got excess pitch trim and it's set for upright flight at medium to flatout speed.

An experienced modeler often does none of the three tests. Lots of them simply pay close attention to what happens to pitch when the plane slows down. There isn't any horizontal tail that's been carrying around extra nose weight that will keep the plane level as it slows down. When nose heavy airplanes slow down the trim pitch force weakens.
Old 01-02-2016, 06:51 AM
  #34  
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Nose heavy airplanes will pitch nose down as they slow on approach. If they're extra nose heavy, they'll keep pointing down more and more. The problem with them is when your elevator throw is so limited the elevator can't hold the nose up, the plane is in trouble. Otherwise, the pilot flies his downwind and base legs getting the plane setup for final. Full scale are taught that power controls altitude and elevator controls speed. (They also have prop pitch, btw.)

Pylon racers often use their wings to slow down. They chop power and work elevator to get the plane in a pitch up attitude. Just enough to slow the plane is what they're after. It's a lot easier to do when you're not flying a pylon racer, btw. High rate works great for this especially for very fast airplanes that live most of their airtime in significantly low rate.

You really land some planes on the downwind or base leg. OK, you set them up for landing, obviously not "land them". Landing doesn't really start as you cross the threshold.

Some special purpose planes often fly like two different planes from high speed to low speed. They're really not the best for every flyer, but you can learn a whole lot from those things. BTW, the Revolver is in the same family with your AWot.

Last edited by da Rock; 01-02-2016 at 06:57 AM.
Old 01-02-2016, 10:46 AM
  #35  
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Another couple good ways to check CG, pull to a 45 degree up line and roll inverted. For 3D type flying you would want the airplane to continue on the 45 or even slightly climb. For more precision type aerobatics you would want a gradual arc towards the canopy. In knife edge flight, tail heavy will tuck to the gear while nose heavy will pitch to the canopy. The biggest two clues for being nose heavy are pitch trim change with airspeed changes and fast landing speeds. These apply to any aerobatic model with a symmetrical airfoil.
Old 01-04-2016, 03:58 AM
  #36  
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BTW, there is a simple way to "check" the balance of most foam-e's. It's easy and doesn't require flying actually. Most ready built foamy models that come with almost everything installed like the AcroWot for example, really don't allow you to change the balance much at all, especially if you use the recommended battery. In fact, the choice of battery is about the only possibility of un-balancing the design at all. The designer made the battery compartment to fit the batteries he tells you to use. A foamy needs all the foam it can get to have what strength they wind up with, so the mfg isn't usually going to provide much wiggle room in what is usually the biggest hole in that beer cooler body.

The AcroWot foam-e comes with the suggestion you use a 3S 2100-2500 battery. They are usually 6oz to 7oz. They don't vary much in weight and the recommended range isn't but 1 ounce.

So how do you figure your CG? Realize that any battery over the biggest suggested is going to risk making the plane nose heavy. But keep in mind that unless you hog out some foam to cram a bigger battery than suggested into that hole, the plane will very probably handle as advertised. Still worried about it? Go on any popular forum that has a thread or two about your particular foam-e and read about it. The people who've actually bought it are a fair source of info. For a European model like the AcroWot, I'm not sure what forums that'd be. But simply knowing whether or not you're using the right weight battery gives you a clue. If you're Not, your Wot might not be balanced. If you are, there isn't much change it's out of balance.
Old 01-04-2016, 09:33 AM
  #37  
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Shopping around and looking at different discharge rate batteries can yield a size variance that would allow for more CG adjustment. Personally I would rather fly a well trimmed airplane for 5 minutes then a nose heavy one for 8. I recently ran into the same situation recently with an E powered sailplane. The recommended battery is 1300 mah. After my initial test flights I discovered the sailplane was very nose heavy even with the battery as far back as I could place it. Since the sailplane is used only for ALES contests where I only need a 30 second motor run I replaced the 1300 with an 850 that had a higher discharge rate. Problem solved and the sailplane flys as it should. Check the spec sheet on the two 2200 mah batteries, some variation is size and weight, going to a 2000 or 1800 would give even more room for adjustment and a slightly lighter pack. The choice would be what's more important, performance or run time? There are always ways of removing weight although each item is rather small it does add up. Examples: can the motor wires be shortened? Can the motor connectors be eliminated and wires soldered? Can a lighter prop be used? Would the OP be OK with the astetics of not running a spinner? There is always a way.
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Last edited by speedracerntrixie; 01-04-2016 at 10:07 AM.

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