Avistarpilot

Hey all, It's been FOREVER since I have been on these boards. Life happened after college and I haven't posted on here in years. I have flown on and off over my hiatus of this hobby but I am planning on getting back in and am currently trying to finish my kit plane that I started years ago.

With that said, I currently have a Hobbico Avistar(real original when I decided to make a screen name lol) I feel comfortable flying this bird but will definately get more time in since it has been a few years since I've flown her around the patch. Question is, I have an O.S. 40LA in there now. For what it is it does the job but I'm looking for something with a little more umph. The kit I am currently building is a Great Planes Super Decathalon 40. My thoughts are to find an engine that I can break in and fly with the Avistar to make it a better performer, and when the time is right transfer that into the Decathalon? I've had thoughts of a .46 FX or a TT .51? I've read that the Decathalon is a bit on the heavy side so a bit bigger engine would help with that aspect. Just kinda testing the waters here to see what others have done. I'm not looking to make this a full aerobatic aircraft but from what I have read & watched the combination of a bigger engine, larger control throws, and zero dihedral and it has potential to be a nice performing aircraft.

Thoughts? I apologize if this is in the wrong section. I still consider myself somewhat of a beginner(this is still my first plane after all), and the Avistar is an advanced trainer so I guess I figured there would be enough of you with Avistar experience to lend a hand.

Steve Steinbring

Yes a larger engine will give you more takeoff performance!

But is it going to make it a different airplane not really, it is still a trainer with or without dihedral. The wing has a high lift airfoil (flat bottom) which somewhat limits aerobatic capabilities. You can go through a lot of trouble trying to modify the airplane to improve its characteristics...... but IMO its wasted $$$$ and effort. The Avistar is a good airplane a nice trainer, but it is what it is! The .40 LA teaches you to better fly the wing vs. flying an overpowered thrust vectored airplane making you a better pilot in the end.

I would go ahead and purchase your choice of a more advanced airplane/engine and keep the Avistar as it is! Everyone should have a trainer in their hanger IMO, there is something nice about relaxing flying with a trainer, good for buddy cording friends, or just doing touch and go's when the mood suits you.

Welcome back!

thebest_102

My Feedback: (6)

As Mythoughs for an Engine I like the OS46 AX and the 55 AX. I have had great sucess with both they have great performance. As to the trainer it is possible to mount those engines on there fro break in and testing but those engines break in fast so it is not a requirement. I would keep the trainer and put the older engine back on if nothing else trainers are a blast to fly.

WaffleMan

My Feedback: (1)

55 ax would work good for you, And I havent heard anything bad about the new thunder tigres.

fredscz

My Feedback: (47)

To be a bit different in response to your questions I have actually had a couple of Avistars with LA engines as well as ST and OS 40/46's. An Avistar is not exactly a trainer because of it's semi-symetrical wing. While it can be used as a trainer it is a lot better plane for simple aerobatics than a flat bottom wing trainer. All those I have seen were Semi-symetrical but it's always possible they made a flat bottom wing version.
I flew one for a long time with a Thunder Tiger 46 which is a very good engine(not to be confused with a Super Tigre). Your problem is going to be weight. The avistars I have had easily balanced out without any extra lead using an LA engine, so if you use a ballbearing 40/46 you may need quite a bit of weight on the tail end to balance it. The OS55 is an even better engine but does weigh just a little more than most 46's.
I have flown two different 40 size Decathalons and both were a real handfull on the ground. You might do some research on them and get advice from those who have actually had the plane. Be carefull using a two stroke on a plane that you plan to invert the engine. 4 strokes work well that way but two strokes can be problematic no matter how well they are tuned. The Decathalons I flew had side mounted engines.
Fred

Jacobs Jasta 7

The Avistar is a great little plane. I lost mine in a mid-air about a month ago. I agree with everyone this plane is not a beginner plane, but maybe one step up from a trainer.


Pete

gene6029

Avistarpilot, the Avistar with an OS 55AX is a rocket! I flew mine for a season with a OS 40 LA then switched to a 55AX, its unreal. I have recently dropped a 40 back into it and added another servo along side the original so i could add flapperons. The Avistar is a real performer with both motors & will lift off with flapperons in under 20 feet even with the 40. I have dozens of planes to fly, but still get a kick out of flying my old Avistar. I have won fun fly events with it, so its not just a trainer.....Gene

Avistarpilot

Thanks for all the replies guys, keep em' coming. This is exactly what I'm looking for. I think while I'm in build mode I may so some slight modifications to my avistar as well. I have epoxied the wings but I think if I'm planning to get a .55 I will glass the joint as well. Wouldn't mind fabbing up a dowl & screw hold down as well. I don't trust the little metal straps. If I can dowl the LE and screw the TE and throw a few rubber bands on for good measure the wing isn't going anywhere. I still plan on keeping her in my arsenal. But as of right now my arsenal consists of my airworthy avistar and a Decathalon that is at best under an experimental certifcate haha.

Thanks for the replies once again, I defiantly got the itch again! I'll have to contact my old club and re-join. Looking forward to lurking around on this board!

Rotten40851

My Feedback: (2)

The Avistar is a great little plane, it is capable of aerobatics as well as training without any modifications. You will need some more power than that LA 40 though. I have taught students to fly on differant kinds of planes and I think the Avistar is best. I would definetly say the O.S. AX 55 as your upgrade. I have flown the Avistar with this engine and she flies real nice, plus you will need the extra power for the Decathlon as they are a little dicey with that short fuselage  taxiing down the runway.  Good luck, hth    John 

Rotten40851

My Feedback: (2)

One more thing, Important!! Make sure your Avistar is balanced laterally. Hold the tip of the spinner and the bottom tip of the rudder and see wich side is heavier. add the correct amount of weight to the light side ONTHECENTEROFGRAVITY!! remember (adding weight fore oraft of the CG changes it) sounds stupid but has alot to do with tracking straight through your manuvers. John

JollyPopper

My Feedback: (6)

I have an Avistar with an Evolution .46 on the nose. It turned out to be a great combination. I got tired of the rubber bands on the wing fiasco so I figured out how to route velcro straps to hold the wing on. Many of the veteran pilots at my field flatly told me it would not workuntil they saw me do it. I am confident that you would break the wing before you could rip it off with the velcro holding it on. These things go on in seconds where it took several minutes to stretch those rubber bands and the velcro does not break while the airplane is sitting in the hot sun. So far I have used this on two different planes and I have yet to find a down side to it.

levram1

My Feedback: (1)

How about posting some pics?

Stuntpilot51

Here's a real early pic of the first Avistar arf back in 1991. Sorry for the poor quality it's a picture of a picture, we had no digital cameras back then.

Mine started with a O.S. 61 4 stroke and then I wedged my first O.S. 91 4 stroke on it.

Had alot of fun with this setup. Only other suggestion I might make is turn it into a taildragger.

This early version also had a semi symetrical wing which had a bit of dihedral which was removed, I think as stated this newer one has a flat bottom wing.

levram1

My Feedback: (1)

I was meaning JollyPopper with the velcro wing attach setup.

CGRetired

My Feedback: (1)

Yeah, but the purpose of the rubber bands is to break away in case of a crash. As stated by Jolly Popper, the wing will break before the velcro gives away.

CGr.

levram1

My Feedback: (1)

CG. I am quite familiar with the purpose of the rubber bands. I too am tired of them I and am interested in the velcro setup.

CGRetired

My Feedback: (1)

Yeah. The problem I have with them is if you don't take care of them right away, ie. dry them out, well, one use and they are done. And, even with that, I don't really trust them for use after the first time. I thought I was all set one day, looked in the rubber band box and there was about 20 of them, about 5 were any good... jeech.

CGr.

levram1

My Feedback: (1)

I buy them by the quarter lb. Shake talc powder in the bag and store them in the lower section of my flight box. I use them for 1 day flying and then toss em.

Weasel Keeper

My Feedback: (16)

I trained a friend to fly with an Avistar powered with a Magnum 52xls i believe it was. This turned out to be a very good combination. He could fly for 20 minutes at half throttle just putting around the sky. Pour the coals to it and you could do almost anything you wanted. I'd say a BB 46 to 55 would be perfect. We had to add a fair amount of lead to the tail, but if you replaced the metal engine mount with a glass filled nylon mount it might balance without the weight. Wish my Magnum 52 ran as good as his did.

skyraider71

I flew my Avistar on an AX .46 and it was a ball to fly. It took off in 25 feet, and had plenty
of power to pull it through basic aerobatics...lots of fun.
Just be aware that The Avistar was designed for the LA .40. The AX .46 is heavier, I had to
move the Rx pack behind the servo compartment to balance. It was easy to do though.
I regreted selling it.

JollyPopper

My Feedback: (6)

levram1, I apologize for not checking this thread again until now. I currently don't have any picutres of the velcro setup, but I will take some later this evening and post them. I can try to explain the process. First, you must buy velcro that has no adhesive on the back. Also buy all nylon velcro rather than the stretchy kind. Buy 5/8 to 3/4 wide, depending on what you can find. Now take the fuzzy half and sew a loop in one end of it, the loop being big enough to go around one of the pegs that you normally put rubber bands on. Place your wing on your plane and put the loop around one of the rear pegs. Now, with the fuzzy side up, pass the velcro over the top of the wing and behind the front peg. Cut the strip of velcro as if comes around the front peg. Now remove the strip from the plane and sew the hook half of the velcro to the fuzzy part so that the hooks and loops face each other when you put the velcro back on the plane and come behind the front peg, go around the peg and back up over the wing. Pull snug and mate the two halves of velcroc over the full cord of the wing. Bring the velcro to the trailing edge of the wing and cut it off where ever it looks good to you. As cgretired stated, this arrengement may or may not break away in the event of a crash, but Iwas just sick of stretching those rubber bands and having them break and snap my hands and then the ones that didn't break do so after the plane sits in the sun for awhile. Velcro won't break or snap your hands. It can be put on in seconds and looks much better than the rubber bands. I have not crashed or hard landed a plane while using this setup so I can't say what happens, but regardless of what happens, I will not go back to rubber bands. Just my opinion.

Avistarpilot

I guess I wasn't aware some avistars were a flat bottom wing. Mine is Semi-symmetrical airfoil so that's kinda why I am contemplating doing a little bit to it. What started this thought was a video I saw on youtube while "working"...It was an Avistar with a .50 something I believe and he was doing all sorts of acrobatics, and hanging the plane on its prop a few feet off the ground, and then powers straight out of it. There's no way the little LA is going to do that. I can do basic aerobatics just fine with that but vertical flight is very limited. After seeing that I was hooked. After reading some of the comments, according to the pilot all that was done was the larger displacement engine, he took a little dihedral out of the wing, and increased the control throws. We'll see but since starting building this decathalon it has got me in build mode. Im gong to try and fly her(avistar) this weekend to get my feet wet again after a year or so of being on the ground, and then fly the crap out of it and get comfortable again before I go crazy with it[8D]

skydvejam

I have one myself and it is semi-symmetrical as they all are. They are known as a sports trainer, I have a Sensei that is a flat bottom trainer and the wife and kids can putt putt in that one all day, but they always have an issue with the Avistar lol. Anyways I only have a older OS40 in mine, while it does OK, I still long for more lol. I am getting a 60 size mid wing for more though and putting a 75 2 c in the nose, that should do the trick