vertical grimmace

My Feedback: (1)

Way to get me back on track Bozarth! By the way, you want me to do another race up here next year? We will set our schedule soon.

bogbeagle

Increasing the aeroplane's weight will increase the stall speed, but it won't alter the "float". The L/D will remain substantially the same; just that everything will happen at a slightly higher airspeed.

BMatthews

VG, you're calling the model a garbage heap but you're having to add things to kill the model's performace to make it behave in a manner that allows you to teach the students how to deal with stalls? I'd say it sounds like the model is just fine and if it is suffering from any problems it's one of being too light for your tastes.

You say it speeds up and floats in the landing approach if the student pushes the nose down for any reason. That's entirely normal. What tis means is that the student needs to learn to keep the nose high with elevator trim or stick pressure and vary the descent rate using a click more or less of throttle. This is how full size airplannes do it and it's how I had to make my own approches with a super clean airframe Quickie 500 set up with "only" a .25. If I didn't concentrate on keeping the nose up a little it would just float right on down the runway and it was time to power up and go around again.

If the issue is that the model design is so clean that it just does not want to settle into a stable and adequite descent rate than upping the stall speed isn't the answer. What you need is added drag so that the glide is not so efficient. And spoilers is not the way to do this. Spoilers certainly kill some lift but they also induce a strong nose down pitching action if they are the typical model type upper surface only sort of spoilers. And while adding sharp triangular strips to the leading edge will make the airfoil stall easier and more sharply they mostly make the stall more abrupt and only have a slight effect on the actual stall speed. The stall speed being related more to wing loading than other things.

If the wing uses strip ailerons I'd say that the best way to kill some of the float on the approach and to force the students to establish a proper nose up and thus draggy descent is to reflex the strip ailerons a bit. Maybe as much as 15 degrees but after that other oddities may occur. You'd have to test for such things. It's still not idea but at least it alters the airfoil so that it's more draggy when slowed down. By reflexing the ailerons you're also putting some negative incidence into the wing. Up elevator trim will be required to compensate. Also at the same time you do this you're effectively reducing any existing downthrust so don't be surprised if the model wants to nose up with added airspeed.

vertical grimmace

My Feedback: (1)

I think if the opportunity arises, you should fly one of these Nexstar's, stock, with the added Leading edge droops and little plastic speed brakes and form your own opinion of this aircraft. There seem to be so many marketing ploys these days to tempt new pilots and promise the world to them, it is just annoying. Ever try flying those old Cox plastic .049 planes? Same thing really. Except that this airplane will actually leave the ground. These airplanes are virtually unflyable with the droops installed. I will not fly one until they are removed.
Also, according to the advertising, the wing has 2 different airfoils. Now I have done this many times with my designs on tapered wings, but I find it unnecessary to add a higher lift section at the tip, with a hershey bar wing. I feel this may be where some of the trouble is.
I originally mentioned reflex and may start there. We are not even using the throttle on approach. I am guessing that the prop needs less pitch. That should help. Tomorrow is trainer night so I will report back in. One thing is for certain though, I have a lot of time on this design, and nothing will change my negative opinion of it. It can be made to fly OK but only after all the junk is removed.

anuthabubba

My Feedback: (102)

Just cut a rib bay or two off each wingtip.

Terry in LP

TFF

If a buddy box is used, the garbage would have never made it in the air much less the first engine run. I make all students take it off. It only has a use if you live in the tundra and the plane was delivered by dogsled.

vertical grimmace

My Feedback: (1)

Yes, cutting that "other" airfoil off might just be the ticket. Maybe I will try to talk them into that! First, I am going to try an 11.5" x 4 prop. I think this plane firstly needs to get a lot slower. I will know tonight.

BMatthews

I have to admit that I haven't flown one. And from your report I'm likely a far happier person for it...

The modelling community tends to grossly overpower everything based on the idea that "you can always throttle back". But at some point even idle is enough power to fly a plane. Perhaps this is a key part of the issue with these? If so adding a flatter pitch prop should help.

vertical grimmace

My Feedback: (1)

The engine is an OS .46 FX essentially and is very strong. One of the better aspects of the plane. I literally saw a guy last Sunday, who is soloed and somewhat proficient take one of these aircraft off and It just flounder with no penetration like it was very tail heavy. He almost lost it several times and was lucky to land it. I looked at the plane after he landed and sure enough he had the droops on. That is how it handles with them and they really throw the plane out of trim. It does fly OK after they are removed I must admit.

Bax

My Feedback: (11)

If a model will "flounder with no penetration like it was very tail heavy", then it either IS tail-heavy, or the modeler is trying to fly it in too much wind, or fly it too slowly. Many of the features of the Hobbico NexStar were designed by some of the finest R/C flyers in the world...one of the members of the design team is a former European Pattern champion, and others are highly-experienced IMAC and scale flyers and competitors...as well as knowing airplane design inside and out. The design team worked with many non-flyers in the development of the NexStar to check its suitability for training novice R/C flyers. The features of the airplane were not put on for "marketing purposes", but for very real reasons...to suit very real-world conditions...to train very real-world R/C flying novices.

Also, we noticed that you mentione that one person was "soloed and somewhat proficient"...perhaps not as proficient as all thought. The wing droops (or flaps or both) did not cause his problems. It was his flying skills (or lack thereof). There was no mention of the model's balance or trim condition. At what throttle setting was it trimmed for level flight? Was the modeler trying to be too active on the controls? That's a common problem for beginners.

Fly the model at reduced power settings, and you'll find that it handles like a dream. It's great to fly 'round and 'round the pattern doing touch and goes. Just use good throttle management. Yes, handling will be greatly changed when you remove the flaps and wing droops, but that's only to be expected...real aircraft have noticeable trim changes when you deploy the flaps or retract them.

All in all, the Hobbico NexStar is a fine-handling airplane that can be used to teach a variety of people to fly R/C airplanes, and has features that make a lot of the teaching easier. Those features were all carefully considered and tested long before the model was ever released. Several thousands of Hobbico NexStar airplanes in the hands of modelers are a testimony to the effectiveness of the design.

Jezmo

I have personally flown and taught others on this plane both with and without the added aero devices. The planes I am refering to were the students but in all cases, before taking off, I checked for proper control direction and deflection amount, proper balance, radio functionality, and proper assembly of the plane among other items. This is part of my safety process before teaching someone to fly and I also try to teach them why I am doing these checks and what they mean. In my experience with this plane it has some different flying characteristics than most other trianers I am familiar with but in no way was it "hard" to land. It certainly didn't seem to "float" any more than the other flat bottom airfoiled trainers out there that are equally as light as this one. Most have had the OS LA series 46 on them although one fellow had a SuperTigre G45 on his. Yes, they removed the aero devices after they had progressed some and Yes the trim needed to be changed afterwards. Once properly trimmed they flew great without the aero devices just as had been expected. The planes all had ample power and each student flew these NexStar's until they were ready for something more advanced. I never found landing them to be a particular challenge especially when compared to other flat bottom airfoil "Trainers". Just my two cents, you're mileage may vary.

vertical grimmace

My Feedback: (1)

Not being affiliated with the hobby industry, and only having a genuine desire for a new pilots success without entry into their wallet, I will not back down from my negative feelings about this design. I have flown at least 3 of them and they were set up stock from the factory. I get exactly the same feelings from the other instructors in the club. I will not, or cannot recommend this plane. Maybe they just have a different characteristic at 5,000' of altitude where we fly.

Oh, the students were no shows, so it looks like I will have to wait another week to try out these ideas. I am confident the prop will help.

TFF

That stuff is really for people who want to do RC and have 0 way of instruction. The first time I flew one it had the stabilization still plugged in. I was asked to fly it to see what was going on because it would not trim. The stabilization kept turning into the Sun. Yanked that first then the flaps. If I lived in the country and one showed up under the Christmas tree your best shot is to try as is. With an available club the stuff is not needed. You have to configure to your situation. One problem comes with new people is, in there mind they spent a bunch of money and they think it is the last plane they will ever have; to change it hits their ego of either buying the wrong thing or because their understanding is not there it screws with the logic of if they put it there why do we need to remove it? Getting the trust of the student is tough.

gerryndennis

VG, My first experience with this concept was when a guy turned up at our flying field with his first model (a P51) and asked if someone could teach him to fly it. Being the instructor I started into the 'We'll get it airborne and give you a go, but you'll need to build/buy a proper trainer to learn on before you can fly this' speech when I noticed the clear plastic leading edge droops. So after familiarising myself with the concept we got stuck into the training. He soloed on his third day of training, and within a month was confidently flying his P51 and no longer needed the 'training aids'. Brilliant concept and absolutely succesfull.

On the face of it a P51 is about the least suitable trainer you can think of, but;

Add leading edge (NACA) droops to completely tame the stall/spin characteristics to allow slow stable flight and approaches

Add drag plates to the u/c legs and temporarily lock the flaps partly extended to increase drag (allows slower flight with higher/more reliable throttle setting), but more importantly gives a lower L/D ratio which means a normal approach can be made, with some power on, without excessive speed building up, and without excessive floating on touchdown.

Supply a simulator disc so the basic coordination and control inputs can be practiced prior to flying.

As to cost, well it wasn't cheap but when you consider that he didn't have to build/buy a high wing trainer, an aileron trainer, or a low wing trainer/sport model before moving on to a 'warbird' maybe it's not too bad. Certainly too expensive for my taste, but definitely suited this guys time/family/lifestyle balance.

Quality? Well time will tell, but it's certainly no worse than most of the other ARF's out there.

I have seen a Nexstar fly, and they fly very well with, and without the aerodynamic add ons.

Leading edge droops were developed by NACA and are extensively used by Andy Lennon (amongst others), a very clever model designer, they are certainly not a marketing ploy.

I'm reading between the lines of your posts, so please excuse me if I've got hold of the wrong end of the stick. It seems to me that what you are saying is, that you have made modifications to improve the L/D ratio (removed the droops and maybe the flaps) and now the model flys like the L/D is high (speeds up if the nose drops a little on final and floats). Increasing stall speed isn't going to help here.

Can I suggest refitting the flaps and droops, trimming the model out at a reasonably slow (low to mid throttle) speed, and flying it like a basic trainer. As your students gain skill remove the bits and start flying like an aerobatic/aileron trainer.

Please accept my apologies if I've misunderstood your posts, but just passing on what worked for me.

Good luck,

Dave H

da Rock

There happens to be a caveat to that wing droop idea.

Yes, the P51 with droops and brakes is a better trainer than most who're unfamiliar with the concept would assume. Although the addition of the drag brakes on the gear struts isn't really a plus. But it's not the least suitable trainer you can think of at all. Unless you've not seen the "advertising concept at best" F-22 Raptor in all it's glory. The reason I mention that travesty is when you've encountered that "trainer", it's hard to believe that all the wing-droop trainers aren't some kind of fraud, if not a complete one like that Raptor.

Yes, the P51 trainer is way better than probably anyone with experience thought it'd be. I've taught two guys on theirs. But it's not the best trainer and some beginners really do need the conventional high-wing, quicker to return to level trainer. And the Nexstar without the stuff actually is almost perfect. And of course, the F-22 is pretty bad as a 1st trainer. So as with almost everything in this hobby, the application of that stuff isn't a cut and dried given.

The caveat is that all that stuff can and often will make the Nexstar less, makes the already screwed up Raptor awful, and actually turns the P51 into an acceptable trainer, but not one for everyone. It appears that the addition of droops can be a mixed blessing, not a given. As with many things in this hobby, that wing droops turn anything into a trainer idea ain't a simple concept.

da Rock

As for the topic of this thread, the P51's "training equipment" could serve as a lesson that points to somewhat of an answer on how to at least slow the plane, if not raise it's stall speed.

The P51's full equipment includes flaps and speed brakes. The speed brakes work. They slow the plane and make it less dependable, especially in gusty conditions. I've had a couple of students bring P51s. After experiencing their airplanes with and without those brakes, when I have another student show up with a P51 first thing we're doing is pulling those brakes. For learning, they're not really needed as the droops and flaps work well to allow slower speed, and it's lots safer slow speed. At least in my experience.

I guess I don't understand any motive for increasing the stall speed for a beginner. Stalls increase the risk involved. Having a beginner face higher risk won't work with some of the guys who're frightened of losing their investment. And if you've got a student who's blindly brave, there are better ways to scare him into paying better attention than having him fly a quicker to stall model.

tomfiorentino

I have started my 9 year old on the Nextsar. I have the wing droops installed but not the flaps and I couldn't be happier. In fact, there isn't much that I find objectionable. Interesting to note for those who haven't flown it that at higher AOA where the droops become more effective, the aileron control deteriorates quickly and gets sloppy. Rudder authority remains great though and the airplane banks more relative to the same rudder input at higher speed. But hey...learning to use rudder on landing will never hurt anyone! Many of us can rationalize the aerodynamics of that but its all the right stuff in all the right directions for teaching a new pilot IMHO. Furthermore, outside of it being a high wing, removing the droops and brakes provides a nice flight progression as I think lots of time trainers get boring a little too quickly for some of the kids.

Another observation is that the fuse is really, really tough and is substantially built. This, in combination with the vibration mount, makes the plane very quiet with none of those irritating harmonics that shake and rattle many trainers.

Looking forward to flying it off the snow...which won't be long in Upstate NY!

Food for though I guess....

Tom

rmh

Not trying to claim "which is the best setup" but.
you simplycan't beat going lighter - for easiest landing techniques.
The lihtest setups simply require no flare and can be flown at extremely slow speed -right to the ground
An example is a Seniorita -
Mine has a wing loading of 11 ozs to the ft
with the coupled rudder/aileron controlthe only roll/turn/yaw input is of course -the rudder
It really works well except of course in a cross wind
the model is not good in a cross wind.
My Taylorcrft -tho much larger has a wing loading of 24 ozs to the ft
It will land slowly but nowhere as slowly as the Seniorita - the Seniorita will stay aloft at about 15 mph
For the scale buffs the Seniorita is too light for anything except basic training .
For the scale lightplane buffs - the Taylorcraft setup is very good - as it will control in light crosswinfs fairly well
If you really want to successfully learn to fly overweight scale warbird stuff . you have to learn flap use .
learning flap use is a whole different ball game and offhand -I can't think of a "flap trainer" I really like.
Flaperons are a mixed bag ,so Ireally can't recommend them to anyone
The old Zlin 526 training craft had inboard flaps and were excellent stable planes which were also good areobats
great Planes has a new 526 AFS -I only glanced at it but it may be a good transition plane
The 526 AFS was essentially a 526 with severely clipped wings.

vertical grimmace

My Feedback: (1)

The Seniorita is a great example of a wonderful flying trainer. Good basic design that is not comlicating itself with gimmicks. Too bad more aircraft like this do not show up on trainer night. I flew a Hanger 9 Alpha last week. Another great flying aircraft. Hope to see more of those as well.

iron eagel

Try another prop.
The NextStar comes with a 11X7 on the OS .46, go to a lower pitch and it will slow right down for landing.

vertical grimmace

My Feedback: (1)

I am actually not sure what prop they were running. It was not the stock prop though. Regardless, I am sure it had too much pitch.

PA441914

a few things

cyclops2

Post # 6 says to me. Somebody has found the perfect COG for that plane. I balance everything to get that same condition. LOVE it.

Fail safe.... of the RC receiver & ESC is EASY. Circle & no throttle. Neat way to save a plane.

sensei

I also agree; the easiest thing to do is add weight on the C/G, that old stall speed will move right on up just as far as you want to push it. The nice thing is you have not modified the airplane so you can just pull the weight back out when your done.

Bob

hugger-4641

My Feedback: (6)

Try moving the CG foward.  I use mostly Avistar's for training and I usually want the CG back so they will land slower, but with the Nexstar you will probably want the CG near the front of the limit. I have helped a couple people learn how to fly their Nexstars because they had already bought the plane before asking my advice.  I agree that the Nexstar is a less than desirable trainer in my book. It can be made to practically take off and land itself if you remove all the junk and have the right prop. But I don't think this is the best way to train people. If they just want to fly the easiest thing there is to get in the air, then I tell them to get a hobbyzone supercub, which I do use for training as well. But if they actually want to learn how to fly a nitro plane, they need a plane that actually makes them learn how to fly and not just float in and plop down. Just my opinion.