You're correct, if you land hard you may have a problem. I sometimes fly off of very rough grass fields. With a springy tail gear the tail can bounce up further on taxiing, than it would when it was accelerated and lifting for take off.

You need to look at your particular setup and figure your prop clearance accordingly. With the Ohio Tail gear being so stiff, but higher than the stock unit, flying off pavement with a 14 or 15 inch prop isn't much of a problem, unless you set down really hard on landing.
I tried a 13X6 and 13X8, but felt the engine was revving too high with such a small prop.

I compromised and settled for a MAS 14X6. The engine is revving to nearly 10grand on this prop. I am afraid that in the air it will go much higher, so I set a really broad power curve on my 9Z to prevent accidentally over revving.

Of course, the proof of the pudding will come, whenever the weather lets me test fly it and see how it goes. I did remove the wheel pants and installed a little larger, stronger main wheels and smaller tail wheel to enhance using the 14" prop. The brown truck brought me a new GB Obsession last Saturday. Nearly have it finished. Waiting on a 8611 servo to come for the rudder. Once that's in, it will be ready to test fly too. Weather man forecasting rain and wind again this weekend, so don't know when I'll get out my first flight reports. I have three new planes in the hangar waiting test flights.

Don't trust the stock wheels, both of mine failed the first time out. The plastic on one just shattered during take off attempt. May have had a piece of debris get kicked up into the whell pants, but they didn't show any indications of such.

Hope you are having better luck with yours than I have had with mine so far.

Mike Boyd
AMA 7197

Some people do two point landings and some do three points. I never understood why you would want to do a three point. I think a two point would show more skill.

But hey, I only burn holes in the sky and spray burned fuel.

But I do try to stay away from the one point landings.

ROFL Those one poiters are killers....
Only three point take offs and landings I see are with the 3D stuff... Like I said though we have a paved runway ... Grass is probably different... I like the nice long scale take offs and landings myself.. But that is just me .

I put a APC 13X4 on my .56 and seem to have enough clearance.. Guys are telling me it is more pull and less speed then the 12X6 I had on it... First good day we will see...

welp i desided to change engines in my decathlon, I'm going with a new Saito 82. Any thoughts on this ?

OH NO!!! I tanked my decathalon today at the field. A total dumb thumb. Straight in. Components are OK, but the airframe is a total loss. LAME!!! This was by far my favorite plane ever. It will be replaced!!!![>:]

I had a MAS wooden 14X6 on mine when the left wheel broke and it did the ground spiral, with the tail up and didn't even come close to touching the prop. My .91 FX really likes an APC 15X6, but the extra 1/2 inch over the 14 inch seems like it was pushing it. That is why I went with the 2 3/4 inch replacement wheels. Someone recommended 3" for grass. this would be a very solid suggestion also.

DON'T TRUST THE STOCK WHEELS, mine broke on a paved runway. Granted my plane weighs a little over seven pounds, but they still should not have shattered the hubs like these did.

The weather man is talking more trash weather for this weekend, 3/25-26-06, so doesn't look too good here in central Texas for the fourth weekend in a row. But the rains have come and the fires are out, so there is a silver lining to these clouds.

Good luck to ya'll!!

Update 3/27/06, wind blew intolerably last weekend, so still no flight report. I went out in the wind with the UCD .46 and the new obsession on Saturday, but too chicken to fly a highwing tail-dragger in 20 MPH+ cross winds on a maiden flight, with such a small plane with light wing loading. The obsession went dead stick, but glided easily back over the lake and through the trees, onto the runway without incident.

Maybe next weekend????

I don't usually use the stock wheels.. I don't like the cheapy foamy things that come with most.. I have a weird thing going on with mine.. To trim it takes around 3 clicks of right rudder... For take off ease I have to take it out and then put it back in once airborne.. Still truing to figure out what is causing me to need this.. Don't think it is engine offset as it is required at all throttle settings... The rudder seems to mounted straingt as near as I can tell.... Nothing serious but it is bugging me I don't know why.

Iron, it could be a thrust angle issue...but we'll see if mine exhibits something similar.

Anyway - Since I was out of town most of last week and the weekend weather was lame I've been working on it to get it ready for Saturday morning. All I have left to do is mount the wing servos and balance and she's ready to go. I'll take some pictures tomorrow and post them.

Great, never enough pictures

I've installed a HB .61 in mine and had to mount the battery in VERY rear of the fuse to get it to balance at 90mm.
The HB .61 weighs 14.3 oz without muffler(Very Light!!!)
Good luck trying to balance yours without extra weight.

OS 70 Surpass 22 oz
Saito 72 (Engine Only) 16Oz
Magnum 46 16oz
OS 46AX 17.2oz

MAgnum .91 RFS - ~22 oz...how much does your muffler weigh?

My NASA calibrated left arm scale says about 2-3 oz. It's hollow cast aluminum. - the muffer, not my arm.

Well; It took 6oz to balance at 90mm behind the leading edge.

Needless to say some movement will happen of some radio gear shortly but this weekend I have to fly it. The weather tomorrow is looking like it will be okay in the morning with rain starting around noon. I plan to be done by then.

I test ran the engine today and had what seemed to be a good idle but I didn't tac it - it wasn't rolling though which is what I shoot for. Seemed reliable which I always worry about with an inverted engine. But...tomorrow if all looks good she flies.

Looks good Mike. I had the Magnum .91 FS at 135 deg. and never had a problem running. I really liked how it idles with the McCoy 59 plug.
Since my club has lost our field, I wont be flying mine until May [:@] when the new field will be ready.
Flight report is mandatory!

Alright; First flight went well. I had eyeballed the control throws and they weren't too far off but they were a little more than needed and the rudder was very powerful on the first flight so my takeoff roll wasn't that pretty.

So the first flight went well; I trimmed it out and did a few passes to confirm the trim slow and fast and it seemed good so I then went to slow speed stuff. I like to get real familiar with how and airplane stalls and this one seemed to stall to the right gently but then when I Would try recovery it would recover "badly" in that it was hard to get flying again. It didn't seem snapish just that recovery took some effort - so...don't stall low. Also I know I need to do some more balance work on it so maybe that will help a bit. Entry to the stall was fairly gentle and it didn't have a thing for snapping badly so that's all good.

Landing was nice too; I just brought it in with some power and it held a nice mild nose high stance and I just used the elevator to bring it down. It doesn't float in at all really and because of the poor stall recovery I wouldn't advise trying it.

The next two flights were some fun and aerobatics. It'll hold knifedge easily but it does have a lot of coupling issues. I had to hold hard opposite aileron and some nose down to keep it straight but it did it well. It also tends to go nose high in aileron/elevator turns so rudder coordination is a good skill to have (unless you're lazy and want to mix it in). Even with a little nose heavy as I had it it still did very well inverted requiring only a little down elevator to hold it. It snapped okay; I think the nose heavy held it back a bit here as it wouldn't really get into the snap until well into the second turn. Still it was fun regardless.

All in all I'm very pleased with it and feel like it's a good scale flyer even though I have it over powered. I think something like a strong 50 2 stroke or a strong 70-80 4 stroke is the sweet spot and that the 91 is a little overkill but that's what I had and it was the only engine on my shelf calling to me constantly for use (it hated being on the shelf and proved it today with its behavior).

With the tank moved as I mentioned earlier in the thread I had a nearly perfect idle with 20/20 and a 14x6 mas prop. I have an APC but the MAS looks better in this case; otherwise I would never use it (they flew way too much). I'll probably try the APC next time.

All in all I am very pleased with it and think it's going to be a nice airplane to have in my hanger. I do think it needs a few pinstripes though.

Forgot to post the pictures...

Sound good Mike. Can't wait to fly mine. I've heard reports that she's snap happy at 100mm balance point. I think from your report that if may be fine at 100mm. What do you think?

Mine is balanced at 90 and has not shown any snap tendancys.. Yet I have induced a stall several times at altitude generally the nose just drops and recovery is not an issue.. It is one of the easiest landing planes I have... I ususally chop the throttle on the last leg and she will settle in for beautiful two point landings...
Pin striping does improve the looks IMHO... I went to the auto store, picked up some double line and used it on mine.. I like the look much better

I think it would be quite snappy at 100mm; Today I started at 90mm and then 3oz fell off - now I'm not exactly sure where it is but I flew it nose heavy like that and it was fine.

I'm going to move the servos back into the tail in the coming weeks and liberally laterally balance it better.

With my Saito .56 (15.5oz) I have the battery pack (1700 mah) mounted to the back of the former closest to the wing bolt down plate.. I think I may still be a tad tail heavy... I am going to tack a couple of ounce of lead in the nose and try it as soon as this weather straightens up.. As is the plane will tend to mildly porpise unless I am careful with the stick... This is sure a nice combo for some nice relaxing flying....

Almost every reference I have heard in regards to this planes handling qualities, point to the fact thats its actually quite scale in its handling. I flew one for about 120 flights before I planted it firmly in the ground goofing off. It can be a bit slow recovering from unusual attitudes and that is consistant with the handling of the real plane which I also used to fly about 20 years ago. When recovering from a stall it was imperative to not use too much elevator control after the initial recovery. Doing so often resulted in the plane wanting to again quickly restall or go into what in full scale flying is referred to as a secondary stall. Killed many an aspiring aerobatic pilot. Problem is if you stall, most pilots want to immediately get it flying again and this hasty attempt is what often leads to the fatal secondary.
I was flying my Decathalon with a Magnum 52 four stroker. It handled very nice, was not overpowered but pleasent. I enjoyed snapping it deliberately at low altitude and predictably it met its demise in such an episode. Crap. LOL I will agree with most everyone on here that its one heck of a value for the buck. I replaced it with the Phoenix Models 300 extra and its just as much fun and even $10 less. Same engine but this thing rockets along on the same power. I'm getting the feeling that pretty much all these Phoenix models are good value.

Very informative thread! I've got to say, it's been interesting to read the posts from you hot-doggers but, what about us up and coming greenhorns?!!!! I did a search on the forum looking for threads about this plane because I'm looking at using it as a stepping stone in my progress as a more proficient flyer. I had already put together a wish list consisting of the Phoenix Super Decathlon and an OS .46 LA engine (2-stroke). I like my Saito 50 on my trainer and I've had a high-revver on my 20-size T-Craft. I thought of putting a Saito, like the 56 on this model but decided that I'd just go with the much lighter .46 2-stroke instead. Any help I can get in keeping it in the air is appreciated and losing wieght has GOT to help, no? I've flown my T-Craft a few times but it eventually became a lawn dart. Probably going to fix it but for just over 100 bucks, this plane looks like a great deal, and it's a little larger than the T-Craft (More stable?) I hear everyone looking for more than scale performance but I've got to wonder, would the lighter engine and scale performance be my friend under the current learning condition or is having the additional power to pull out of a problem a plus? Also, with swinging a larger prop and having more torque, is there more torque roll when you apply the power after a slow-pass? I don't see me knife edging or hanging it on the prop any time soon, but I'm open for down the road (if it stays aloft that long). Any input from those who have flown it?

Andy

Easter Sunday morning, almost dead calm. Take off a little quirky, turns to the left, the tail dropped and it wallowed in rolls. Landed, put in quite a bid of differential on the ailerons and mixed a little left rudder, with left ailerons. Knife edge much better, rolls straighter left and right. Let a very experienced friend fly it. He had near perfect knife edges, rolling circles, very precise point rolls. The .91 4S with the 14X6 prop gives it nearly unlimited vertical performance. On low rates, flies very scale. On about all you can get high rates, it rocks.

My friend could not believe it was only a $120.00 ARF. I will fly it about 5 more times, so I can fly it in the scale fun fly I am CD'ing in June. Only need to paint the cowl on my Dynaflite SD and it will be ready to test fly in a couple of weeks. I finished the tedious task of pinstriping all the stars and trails yesterday, since it was too windy to fly.

The little Pheonix SD is really a neat little scale airplane. Mine will get floats put on it later this summer. It should have plenty of power to pull it with floats with this engine. That is the reason I went with a .91 in the first place.

Hope everyone has a Happy Easter!!![8D]

Sounds like you had some great flights Think I need a bigger engine in mine... One can only take so much of this slow and gentle (scale) flying

I rechecked my CG and it is about 95 mm back from the leading age. It isn't tail heavy, needs very little pressure, forward on the stick inverted, so I think I will leave it right there. I did put a remote glow connection on the plane also. It is soooo much easier to attach the glow igniter on the side of the plane, than at an angle from the bottom, with the inverted engine. Remember, I put a 1100 NiMH, 5 cell pack and both the elevator and rudder servos in the rear of the plane to get the CG, where it is now, with the .91 Magnum. This engine weighs 23.5 ounces. If I was buying a new four stroke for it, I would go with the new Saito .82 or .91, since they weigh much less than the Magnums and OS's.

This plane should rock on a Magnum .52 two-stroke or OS .50 SX two-stroke and would be much easier to balance with either of these engines. The SD just sounds so much better with the smokin' four stroke in it. I plan to buddy box my grandson with it in the next couple of weekends. This thing is definitely NOT a trainer or even a second airplane, but as far as scale aerobatics, it ain't too shaby!!


Happy Landings,
Mike Boyd