Phoenix Models Super Decathlon ???
 

Hi, I have been flying a Phoenix Models Super Decathlon ARF this last summer. If I let it glide on its own while coming in to land, sometimes it slows down too much the ailerons suddenly become ineffective and the plane will start to drift to one side or the other with out the ailerons having any affect. Has any one else noticed this?? [X(]

RE: Phoenix Models Super Decathlon ???
 

Don't let it get too slow. [X(]

RE: Phoenix Models Super Decathlon ???
 

Well I have never had a plane that does this before! My other planes are responsive until they stall, some. Some start to get sluggish to aileron response like my Sea Fury at slower speeds but you can see it coming. I have never seen or owned a plane that will slow down and glide with no signs of stalling but suddenly not respond the least little bit to aileron input. The throws are to spec which means pretty radical throws so to increase them would make the plane uncontrollable. I have learned to live with it but was just wondering if it could be cured by changing? Add more nose weight maybe??

RE: Phoenix Models Super Decathlon ???
 

On a more serious note, and having had this model before, I have witnessed the symptoms you described. The airfoil of this plane and the small chord of the ailerons does contribute to a lessening of thier effectiveness at slow speed. Being a scale-type aircraft, you have to fly it all the way to the ground. Much like a Cessna, a nose-down attitude should be maintained to keep airspeed above stalling and allow the wings sufficient airflow to maintain thier control responsiveness. Flair should begin at about 2-3' AGL with decent amount of approach on final.

RE: Phoenix Models Super Decathlon ???
 

Thankx for the feedback! I thought the sympton might have been due to the wrong setup on my part. All my other planes will keep sufficient speed up with out interferring with its self sustained glide path so that all I have to do is keep the plane level and lined up until its time to flair. On this plane I have to hold some down elevator to keep the nose down until I am low over the runway. I did have a 40 size Zero that had a very fast glide unless I held in lots of up elevator to slow it down. It was controllable but you had to be on top it. On the plus side, it made the plane very easy to land even in windy conditions. :D

RE: Phoenix Models Super Decathlon ???
 

Primodus, when I saw the plane go into floating mode I would speed up and go around again to land it. After the ailerons stopped working I should have checked if the rudder is still effective. Have you tried the rudder at the slower speeds??

RE: Phoenix Models Super Decathlon ???
 

The rudder is very effective at low speed.

RE: Phoenix Models Super Decathlon ???
 

Very glad to hear that. Thankx Primodus. ;)

RE: Phoenix Models Super Decathlon ???
 

Hi:
I am in the process of assembling a Phoenix Decathlon myself. I am very impressed with the "kit". Question: what engine are you using? What did you do with the muffler? How much of the cowl did you have to cut away? And, last, how do you hide the wires to the aileron servos??

Thanks, Phil

RE: Phoenix Models Super Decathlon ???
 

I am using an ASP Super Series 52 engine with an APC 11-5 prop. The plane has gobs of power and will fly very fast if you want it to with this combo. The muffler points down but the exhaust outlet doesn't clear the bottom of the fuselage. I made a muffler deflector from balsa that I epoxied to fuel proof it and then JB welded it on to the top edge of the exhaust outlet. The fuel hits the deflector and flows against it until it clears the boootm of the fuselage. Because it is outside the the muffler and is open, it doesn't add any back pressure to the muffler or the engine. I actually had to make a big square cutout for the engine. I had to use a needle valve extension and an inline fueler. The wires dangling down from the servos look crappy and I didn't realize that they would be that bad until the plane was completed. Where they exit into the fuselage is also a pain and they get in the way of the servos unless you tie them up. Haven't had time to see how to correct that as yet. Maybe others can offer ideas about that. :eek:

RE: Phoenix Models Super Decathlon ???
 

Thanks for the reply. Yes, I anticipated that the aileron hookup would be unsightly. There has got to be a way to conceal these even if we have to tape them the the underside of the wing all the way back between the hold down bolts. My "Y" connector is plenty long to accomplish this Mickey Mouse solution!

From the pictures in the manual it looks like they are using a OS 46 LA. I suppose the muffler tucks into the already cut out portion of the fuse. I have either an OS 46 AX or a Super Tiger 46 to stuff in this plane. Either should deliver more than adequate power with either a 10 x 6 or an 11 x 7 for better vertical if needed.

Did you seal the aileron gap? It is small but could present a problem with flutter. However, at scale like speed it shouldn't be a problem.

I have heard that the ailerons give up at slow speed but that you still have rudder. Did you find it tending toward ground looping??

Phil

RE: Phoenix Models Super Decathlon ???
 

Sounds like you are under the impression that the wires are outside the fuselage area, they are not. They are run inside the wing and pop out inside the fuselage above the servos. I bought 6" servo extensions and taped the joint before pulling the wire through the wing into the fuselage area. I was referring to how you could see the 2 servo leads through the fancy window as it exits the wing. I had a pilot ready to install and realized that the leads and connections were hiding the pilot so I grounded her. The OS 46 AX would be a great engine for the plane! If you want to use the ST, well good luck to you! I never sealed the aileron gap but I went with larger push rods and flutter has never showed up. On ground looping, with my setup what works for me is to slowly throttle up and watch the plane as it gains speed. There is one point where it will want to suddenly turn to the left. When I see this, I get on it right away with a bit of right rudder just enough to stop the turn. At this point I throttle to full and the plane is ready to take off in about 3 more seconds!! Trying to take off by hitting the throttle to full will start the plane turning to the left right away from the torque which can't be counter acted without causing ground looping. Except for the ailerons not working at slow speeds, I don't find the plane hard to land. As far as flying the plane goes, it looks intimidating with the short and bulky fuselage but its actually a nice plane to fly. hard to fly. I installed fiberglass landing gear, and a Sullivan tail wheel assembly for the tail wheel because I had them. I think you will like the plane. :D

RE: Phoenix Models Super Decathlon ???
 

Mine had a 46AX and it was a great match. Vertical was not unlimited, but it could "get on up". Definately seal the ailerons, always a good bet on an aerobatic plane. Also, while not as bad as the Cub, it does have a bit of a time getting under control during takeoff. I always used the "gun and run" tactic, worked well.

RE: Phoenix Models Super Decathlon ???
 

Thanks Fastsky for taking the time to answer my questions.

I realize that the aileron extensions and Y exit inside the fuse. I just didn't want them to be easily seen. So, I thought about taping them to the bottom of the wing running aft and bring them down at the rear of the cockpit to the radio. I used heat shrink tubing around the connections between the Y and the servo leads. That should hold them with no problem.

Did you fill in the area under the landing gear attachment point? It looks kinda funky the way it is. Did you add the black stripes down the fuse?

I've been flying tail draggers for a couple of years and find that applying throttle gently until the tail wants to come up is best. Up to that point I've held full up elevator so that the tail wheel is effective. Works for me!

Thanks again.

Phil

RE: Phoenix Models Super Decathlon ???
 

I never did anything about the landing gear area. I am not sure what black stripes you are talking about, so no I didn't add any. Here is a pic of my plane at the field. You can see the servo lead wires hanging down inside the fuselage. [8D]

RE: Phoenix Models Super Decathlon ???
 

Hey guys. I've been flying my first plane, a Cadet LT40, for about 5 years now and it's starting to show its age and wear. I've crashed it a few times, and the repair points are starting to weaken, and it just looks tired and sad. It's been a good plane, but I think it's time to pull the radio gear and engine and hang it from a ceiling somewhere. I have a few other models, but I've been looking for a scale high wing sport plane. Most of my experience with full scale aircraft is in Cessna 172s and 150s and (my favorite) Aeronica Champion's, so I've always been partial to this genre of aircraft. I've been considering purchasing the Phoenix Models Super Decathlon ARF and dropping the gear into it, but I wanted to get some opinions from people who have them and have flown them. Firstly, I have an old Futaba 6 channel FM radio that is NOT a computer radio. It works fine, but it does not have exponential rates or anything like that, is this suitable for this plane? Secondly, my engine is an un-ringed OS Max .46FX that runs fine, I know people have talked about the .46AX being good for this model but what do you think about the .46FX? Finally, what do you think about the scale looks of this model, ease of building (and time to completion) and viability as a first scale sport model? (AKA, am I in over my head?). Thanks in advance for your time!

RE: Phoenix Models Super Decathlon ???
 

You are asking about a first scale sport model. The SD is a sport scale in looks, but flies much more like a scale model. It is a great model to develop scale piloting skills, as it is unforgiving of poor piloting. For example, take off requires that the wing be flying before rotation. Some flyers are unfamiliar with that concept. The takeoff roll needs to be much more gradual (like a full scale takeoff) than a typical RC plane to avoid ground looping. It is a relatively heavy model (compared to typical trainers) and requires some anticipation of maneuver response (except snap rolls, which are amazingly quick for that big wing). A quick fix is just to stuff an oversized engine in it and forget about that nonsense of getting the wing flying before take off, etc.

I like the plane, but I recommend it as a "scale trainer" moreso than a second sport plane. Your non computer radoio will be fine. You can set aileron differential very simply by positioning the servo arm so that it gives more up than down movement. Good luck in your choice.

RE: Phoenix Models Super Decathlon ???
 

Hi, the 46FX and the newer 46AX are very similiar in performance(both very strong running and reliable). The newer version seems to have slightly more power and seems to have an even smoother idle than the FX but only by a bit. The engine would power the Decathlon nicely. Your radio is fine as well. The Decathlon is more demanding than a 2nd type plane. Its take off can be a bear unless you throttle up slowly and can then be ready to counter with the rudder when the torque suddenly starts to turn the plane. After this point, the rest of the takeoff is straight forward. I wouldn't suggest it if your only other plane was an LT40. Its too big a jump The plane is heavy for its size but is amazingly fast and responsive. These 2 points alone make it too big a difference from a trainer, never mind the touchy takeoff!! That being said, its a blast to fly if you can handle it!:D

RE: Phoenix Models Super Decathlon ???
 

I've used both an OS46AX and OS55AX on mine. Here is a picture taken last December when the 46 was in it. If you look very closely you can see a light blue silicone exhaust extension sticking out directly below the cowl. Just the tip shows in this picture.

I changed to the 55AX simply to see how it would improve the flying since mine turned out a flying weight of 6' 5oz. That's the heaviest 46size ARF I've assembled in the 13 or 14 ARFs done since getting back into the hobby. It gave a slightly better vertical, but wasn't worth the effort. The 46AX does good enough.

I taped the Y-harness to one of the window frames. Some still shows, but I don't have a pilot inside so wasn't worried about looking odd.

RE: Phoenix Models Super Decathlon ???
 

Hey all, thanks for your responses and advice. I have flown a few other models, specifically a Carl Goldberg Matrix 40 (3D aircraft) powered by a Saito .72 four stroke (it'll go virtical out of sight, and I can do many 3D maneuvers with it) as well as a small electric p-51 (I'm actually building a second scale electric p-51 now with robart retracts and flaps) however, it's size made it's flight characteristics a bit unrealistic. I have experience with full scale tail draggers (Aeronica Champion) so I'm familiar with the principles behind take off in such a plane. I also have RealFlight which I could practice with before hand. But all that aside, it could still be too much of a jump. I would really like to give it a shot, but I would hate to smash the thing on the first go. It sounds like the gear would be fine, especially since my LT40 weighs about 11 pounds and the engine handles it without any trouble. I would have expected the SD to weigh more than it does. It really sounds like a lot of fun, however, it would be the most difficult take off and landing I've yet experienced. The Matrix is actually easier on takeoff and landing than my LT40 since it's so rediculously overpowered. If I set it on it's tale and gave it full throttle it would probably take off virtically. The P-51 is no help either, most of the time I just hand launched it. It would definitely be my first scale model, and it may be too much. At any rate, thanks again for your responses!

RE: Phoenix Models Super Decathlon ???
 

not sure what happened to my ARF. everyone has such great things to say about it and mine has been a dog from the start. First, both wing panels had broken ribs. Great Planes replaced them without question quickly. The assembly manual seems to be missing more than it contains. No directions for mounting the wings (no holes drilled) and the rear of the wing does not sit into a notch. No contact information in the manual. when I finally do get it together, I hope it flies as well as all of yours. No kidding, "my last Phoenix Model"!