It’s done! Let’s hope it flies the way it looks. It’s brush painted enamel paint finish over silk tissue and dope, and the colors match my T-shirt from Venice Beach California! The idea is that it is classic looking with all-new modern technology. It has an O.S engines .65 AX engine, Futaba S-bus servos and Fasst 2.4 GHz control, and Powerbox iGyro 3e.
Complete set of pictures is here, and the build is described in this post.
I wanted to build a plane from scratch last fall, and I chose the Joe Bridi designed Sun Fli 4, from 1968. Two plans exist online for this plane and I chose the RCM plan version. The plane has a variable airfoil which is thinner at the wingtips. Because of this, I chose to have foam cores cut.
I had a plan to make this plane look original, but be all modern on the inside ,with Powerbox iGyro, Sbus servos and an O.S .65 AX engine. I want to paint it instead of covering it with plastic film, so I have finished the airframe and turned it over to my father to have it covered with tissue and dope.
All the build pics are in the Sun Fli Flickr album.
The Super Kaos 60 project came to a successful conclusion last summer. I’m very happy with how it turned out, particularly that it only weighs 2,8 kilos! The engine deserves special mention. After priming, it just fires right up by twisting the spinner slightly by hand. What a wonderfully magical metal mystery of fire, smoke, sound and happiness. Planes and engines like these are what will keep me in this madness for years to come. The engine tached 10.600 on an APC 11×9, and I tuned it down to 10.450 for consistent running. The 11×8 wood prop was (not surprisingly) all noise and no thrust. APC is the stuff. I have also replaced the stock muffler with a Hatori type 50-size muffler.
She flew beautifully, and the engine ran as it was made to – fast and loud! What a plane. The low weight made for easy take-offs, big loops, fast rolls and slow landings. Perfect. I enjoyed every minute of the build and the first flights. I have put all the photos from the build, finishing and flying up on Flickr and you can see them here.
I’ve been fortunate enough to get my hands on a classic Great Planes Super Kaos 60 kit, new in box, from the early 1980s. Top condition. After it had been maturing like a fine wine for a year or so I could not resist it any longer. I’m knee-deep in building it, and as usual I’m posting all the build photos on my Flickr page, you can see them all here.
It will be powered by a restored O.S .61 FSR ABC, and guided by Futaba S-3151 and S-3152 servos and a Futaba 14SG Radio with a new FASSTest receiver. It will be simple and basic with fixed gear an Oracover finish.
Done! Well, almost. The wing mounting is fastened with four nylon bolts, two for each half. And because of the pushrods going to the tail I can’t reach the ones at the back. I have to modify it to make it more user friendly with a pin or screw to lock it in place, before I can fly it. But it looks like I wanted it to, it balanced perfectly, and hopefully it’ll still fly like the classic Tiger 2 does. More pictures in the Flickr album.
New plane! A very nice ARF from Tower Hobbies, which is relatively faithful to the Kaos design. It features plug-in wings and a battery tray for electrics. I opted for the glow-power option, using the O.S .65 AX engine with stock muffler. The ARF is very well designed and has lots of options for positioning radio gear to achieve proper balance.
Mine came out slightly nose heavy, meaning I had to use the far aft option of positioning the radio gear to its fullest extent to achieve proper balance:
I did not like the way the tank tray was made because I wanted to re-route the throttle linkage underneath the tank, and so I removed the battery tray and made a new tank tray from scratch using the original parts as templates:
The finished tank tray ready for tank installation:
To achieve proper balance, I also had to install the throttle servo at the back of the radio bay along with the elevator and rudder servos. I had to lift one servo higher than another (the elevator servo in the middle, the mod is not shown in the picture) to achieve proper clearance between the elevator and rudder rod connectors.
The positioning of the battery and receiver on top of the servos is a stock option, all the parts are included. It is removable with just four screws, and it works well:
The ailerons are cut for midi-servos. I used BLS153s that I had lying around, and they fit perfectly. I added after-market linkages to suit my own taste:
Since it is a glow-powered plane I varnished the inside of the wing root, and all areas of exposed wood. I also put a thin stripe of fuel proof laquer to seal all edges of the covering and trim, something I find extends the life of any model.
The rudder vas well hinged but poorly sanded so I had to re-hinge it with a larger gap, which I then sealed with a strip of white Oracover on both sides. Benefit is a gapless and aerodynamic hinge line. I also re-hinged the elevator and sealed the gap there too, because the joiner was glued in crookedly.
Throttle installation. The measurements for drilling the hole given by the manual is NOT correct. Mount your engine first and then measure yourself. Remember you have to clear the tank tray behind the firewall!
The cylinder head must be removed in order to fit the cowling. There is a full size paper template provided in the manual, and that makes it easy to get a really good looking engine installation! Do not cut all holes at once. You do not need the hole for clearing the cast ridge on the carburetor, and the opening for the air intake is a little too far back so don’t trust the template entirely. One more thing: When positioning the engine, measure 142 mm from the rear of the firewall instead of the 140 mm stated in the manual. The two extra millimetres makes the cowling-to-spinner fitting easier to adjust.
A very nice looking plane. Well done Tower Hobbies.
I haven’t had a chance to fly it at the time of writing, so in the meantime, enjoy the pictures here.
It was one of those incredible warm and sunny august afternoons, with clear blue skies and just a hint of a breeze, and I brought my daughter along and went flying. We were alone at the field when my Killer Kaos crashed spectacularly.
I tuned the engine. At first it was flooded, and that killed the OS #F plug, so I replaced it with an OS #8. At home, I had shortened the pipe by cutting the header a good 2 centimetres. It worked. The engine ran strong, frighteningly so, as I tached it at 11.200 rpm. Glad I ordered bigger props, I thought, as I took off. Immediately it started leaning out, not providing the power the tachometer promised when on the ground, and I landed a minute later. The engine was piping hot, it oozed heat and I scorched my finger touching the head. I was at a loss, and then I remembered:
The engine was bought used, and when I got it, it was full of burned Castor oil. I always use 15% nitro and 15 % Aerosave pure synthetic blend in my engines. Problem is, this engine was brought up on low nitro and Castor oil and it was made in an era long before the AX-series engines I’m used to now. So I switched fuels, draining the tank and putting in 10 % nitro fuel with 18 % synth/Castor blend oil. The difference was amazing.
It screamed. I was able to turn the needle almost one full turn out, and power and smoke just kept coming. Simply unreal. Delighted, I took off into wind, and the Kaos was tooling along the blue skies like a dragster down the strip, a gorgeous white smoke trail in its wake. It just hauled upwards like nothing else mattered, and I got that incredible, indescribable rush of pure joy and I wanted nothing more than to hammer the throttle and roll upwards until the cows came home. Then it blew up.
I knew it was flutter before my brain even processed it. The elevator boomed for a second with such ferocity, it even drowned out the sound of the engine. I startled so that I pulled the throttle back as pure muscle reflex, attempted a turn towards home, and realized only the ailerons worked. It wobbled, stalled and then went in nose first. It only lasted two seconds.
The engine was buried 10 inches in soft soil. The fuselage from the rear wing mount forwards was smashed. The fuel tank, receiver, two servos, battery, everything smashed. One wing half in pieces, another crushed. Incredibly, the header and pipe seem undamaged. But the plane is a total loss.
The elevator fluttered. No doubt about it. There is a gaping hole where the elevator horn was, and the carbon rod broke where the threaded rod was screwed into it. The horn and link is missing. It’s one of the very few planes I’ve had over the years with a single elevator pushrod, and it will be my last.
I’m really sad. I was in heaven, truly enjoying myself and thinking that wow, this is what all those hundreds of hours in the basement is really all about. The sound, the smoke, the goose bumps you get when you pull up and the plane, your creation, just keeps on going. And then nothing but silence and sorrow.
I’m also grateful, now that the shock has passed. Grateful that a lot of expensive parts survived. Grateful that I had those few minutes of pure pleasure in the skies before it was over. Grateful that it landed in a field and did no harm to anyone. Grateful to have had this plane. I always wanted to fly pattern, and this was the first plane I had that didn’t crash. I flew it in its original version for four seasons, and it really taught me to fly pattern. It inspired confidence, and I felt it even today, that my fingers could do nothing wrong with it. It was… solid. A rock.
The only way to relieve my sorrow is to look ahead. My decision was already made as I walked to the crash site: I will build another. It will take a while, as is my custom, but I have already started to plan my next one. I will build it from scratch, I have my original plan, and using bits and pieces of the wreckage as templates I will build a new Killer and fly it like there’s no tomorrow, and as a homage, the new one will carry one single wing rib from the original with it into the skies.
So long my friend.
We had an informal gathering of pilots to fly, have fun and informally compete in a vintage pattern meet at Jarlsberg airport. The name honors the Norwegian pattern icon Tore Paulsen. I came 5th with my Curare. Enjoy the pictures here.
The O.S engine gave me a little headache. I ran it at home a little bit, and it ran strong and started like any O.S motor should, i.e. with a light flip of the prop. It tached 10.000 rpm on the APC 11×12 and idled smoothly. All was well and then I tried holding the nose up, and it leaned out badly. A lot of tweaking later, I was unable to fix it. I re-did the fuel plumbing and moved the tank a lot further forward and hoped that would solve it. It may have been optimistic having the tank as far back as I did without using a pump or header tank.
On the field yesterday I had exactly the same problems. I switched from an O.S 8 plug to an OS F, and that did nothing. I tried a smaller prop, an 11×9, and that helped a bit. I then tuned it some more and eventually it ran strong. I had one flight where I landed early because I could hear it leaning out a bit in loops, tuned more, and then suddenly it ran like nothing else mattered, not missing a beat going up, down, sideways or anything. Success! The third flight was suddenly bad again, leaning out. Landed in a hurry, tuned, and suddenly it ran great again.
I have a successful track record of making stubborn engines run good, and I don’t intend to let this one beat me. I suspect the pipe is slightly too long, and I think shortening it might do the trick. I will also try an 11×10 to load it up just a bit more.
The plane flew just like you’d expect. I had some wild deja vu’s while flying. I have lots of flights on the old version of it, so it behaved as I remembered, which is a strange sensation when I was mentally prepared for a maiden flight! I was also surprised at how well behaved it was on takeoff and landing, and how well it tracked straight and level. It has no vices whatsoever.
Here’s a before/after photo, with at least 13 years between the two:
All the pictures from the project can be found here:
https://www.flickr.com/photos/aerowold/sets/72157651018400942
The restomod project blogposts:
Restomod part 1
Restomod part 2
Restomod part 3
Restomod part 4