Horseman3381
Well-known member
Hello all, here is my foray into the 2019 Flite Test Fantasy Plane Challenge, Don Karnage’s Triplane.
One of my favorite TV shows growing up was Disney’s TailSpin. I partially attribute it to my current love of airplanes and directly attribute it to the reason I Fly RC. I have friends that have been flying RC for years. I was always hesitant to get into the hobby due to the cost. When they would ask what it would take to get me into flying I would tell them “When someone makes an RC Sea Duck, then I will start flying”. So a little over 2 years ago when I discovered Flite Test and they released the FT Sea Duck, living up to my word I got into the hobby with the Sea Duck being my first plane.
Ever since I started flying the Seaduck I have wanted Don Karnage’s plane so me and a buddy could fly them together. After 2 years or so and having a number of designs under my belt I decided the time has come to make it happen.
I started work on this project a few weeks ago and decided to build it using the FT C Power Pack and a 10” prop which will allow the fuselage to be approximate 5” in diameter. Below is a schematic layout of the version 1 plans I drew up.
The stats of the plane are:
There are several challenges with this plane, the biggest being that when designing a bi-plane you generally want to have at least one wings chord length (depth of wing) between the wings. In this design I am using a wing with a 5” chord and the layout only leaves a 1 1.4” gap between each wing. This means that each wing will not be able to achieve its optimal lift potential.
I started this project 4 weeks ago. I was able to get the plans drawn in a few days, and the plane build over the course of a week after that. Then after waiting 2 weeks for the weather to clear I finally got the plane out to the field this past weekend.
Initial flight test were done by setting it on the pontoons and running it down the runway. This was not terribly successful as the pontoons would either stick and it would nose over, or it would go down the runway, go straight vertical for 5 feet and nose dive to the ground. After the first day of testing me and some flying buddies determined the plane was tail heavy. I took it home and made some modifications to be able to put the battery further forward.
The next day after moving the battery forward we decided to try hand launching the plane. I was able to get several short but controlled 20’-30’ flights out of it, however the plane was still tail heavy and seemed to be lacking in power. We were about to call it a day after breaking the last prop I had brought (10x4.5), when another guy at the field said he had a spare 10x7 prop we could try.
Desperate to get it flying I decided to give it a go. I put the prop on, tore off the pontoons and gave it a go. With this setup the plane now had the power it needed to fly, however it was still tail heavy. I was able to do a lap of the field with the plane at an 85 degree angle. Though this doesn’t sound that successful it proved the plane had the power to fly, and was controllable.
There was only 1 thing left to do, push the battery forward as far as I could so that it was touching the front of the plane and give it a toss.
IT FLEW!
Not only was it flying, but it flew relatively well. It was a little squirrely, but very controllable. Anything short of 7/8 throttle and it started to fall like a brick. But at full throttle I was able to do 6-7 laps of the field (approximately 2 minute flight).
Now came the dreaded problem that has caused many of my planes to crash…. Pilot Error. I was lining the plane up to bring it in for a landing. I took it out a little farther to give me time to bring it down. However when making the turn to bring it in line with the runway I lost orientation and dove it straight at the ground. Fortunately I had high rates on and I was able to pull the plane up so it pancaked instead of nosing in. In the process of this rather impressive STOL landing I managed to break the last prop we had.
BUT IT FLEW!
I do not have any flight video because after the 15th or 20th attempt to get it flying we decided to stop taping. When it finally made it in the air, we didn’t have our phones or camera on us. Though the plane was/is still flyable we were out of props, so unable to get it up again.
I learned a lot from version 1 of the plane, the biggest being where the CG needed to be:
The next step is to make the following modifications to the plane for version 2:
It will be a few weeks before I have time to get Version 2 built, but I am hoping to get a few more flights out of version 1 this weekend and get some video of it.
One of my favorite TV shows growing up was Disney’s TailSpin. I partially attribute it to my current love of airplanes and directly attribute it to the reason I Fly RC. I have friends that have been flying RC for years. I was always hesitant to get into the hobby due to the cost. When they would ask what it would take to get me into flying I would tell them “When someone makes an RC Sea Duck, then I will start flying”. So a little over 2 years ago when I discovered Flite Test and they released the FT Sea Duck, living up to my word I got into the hobby with the Sea Duck being my first plane.
Ever since I started flying the Seaduck I have wanted Don Karnage’s plane so me and a buddy could fly them together. After 2 years or so and having a number of designs under my belt I decided the time has come to make it happen.
I started work on this project a few weeks ago and decided to build it using the FT C Power Pack and a 10” prop which will allow the fuselage to be approximate 5” in diameter. Below is a schematic layout of the version 1 plans I drew up.
The stats of the plane are:
- 1’-10” wingspan
- 5” diameter fuselage with a 1’-8 ½” overall plane length.
- Construction Materials:
- 4 sheets of foamboard
- 3 paint sticks
- 12+ bbq skewers
- FT Firewall
- 9 FT mighty mini control horns
- Flite test C-Pack w/ 2200 mah battery
- 11x4.5 prop
- 3 - 5g servos
- 2 - 9g servos
- 5+ channel receiver
- Radio capable of being programmed to run dual elevators
There are several challenges with this plane, the biggest being that when designing a bi-plane you generally want to have at least one wings chord length (depth of wing) between the wings. In this design I am using a wing with a 5” chord and the layout only leaves a 1 1.4” gap between each wing. This means that each wing will not be able to achieve its optimal lift potential.
I started this project 4 weeks ago. I was able to get the plans drawn in a few days, and the plane build over the course of a week after that. Then after waiting 2 weeks for the weather to clear I finally got the plane out to the field this past weekend.
Initial flight test were done by setting it on the pontoons and running it down the runway. This was not terribly successful as the pontoons would either stick and it would nose over, or it would go down the runway, go straight vertical for 5 feet and nose dive to the ground. After the first day of testing me and some flying buddies determined the plane was tail heavy. I took it home and made some modifications to be able to put the battery further forward.
The next day after moving the battery forward we decided to try hand launching the plane. I was able to get several short but controlled 20’-30’ flights out of it, however the plane was still tail heavy and seemed to be lacking in power. We were about to call it a day after breaking the last prop I had brought (10x4.5), when another guy at the field said he had a spare 10x7 prop we could try.
Desperate to get it flying I decided to give it a go. I put the prop on, tore off the pontoons and gave it a go. With this setup the plane now had the power it needed to fly, however it was still tail heavy. I was able to do a lap of the field with the plane at an 85 degree angle. Though this doesn’t sound that successful it proved the plane had the power to fly, and was controllable.
There was only 1 thing left to do, push the battery forward as far as I could so that it was touching the front of the plane and give it a toss.
IT FLEW!
Not only was it flying, but it flew relatively well. It was a little squirrely, but very controllable. Anything short of 7/8 throttle and it started to fall like a brick. But at full throttle I was able to do 6-7 laps of the field (approximately 2 minute flight).
Now came the dreaded problem that has caused many of my planes to crash…. Pilot Error. I was lining the plane up to bring it in for a landing. I took it out a little farther to give me time to bring it down. However when making the turn to bring it in line with the runway I lost orientation and dove it straight at the ground. Fortunately I had high rates on and I was able to pull the plane up so it pancaked instead of nosing in. In the process of this rather impressive STOL landing I managed to break the last prop we had.
BUT IT FLEW!
I do not have any flight video because after the 15th or 20th attempt to get it flying we decided to stop taping. When it finally made it in the air, we didn’t have our phones or camera on us. Though the plane was/is still flyable we were out of props, so unable to get it up again.
I learned a lot from version 1 of the plane, the biggest being where the CG needed to be:
The next step is to make the following modifications to the plane for version 2:
- Relocate battery hatch to the bottom to allow better installation of battery in the appropriate location.
- Modify the pontoons to have concealed wheels in the bottom for runway takeoff.
- Design an air duct into the plane to locate ESC in to help with cooling due to over-proped motor.
- Attempt to reduce the weight of plane by eliminating unnecessary internal structure.
- Lengthen wingspan by 1 ½” in attempt to get a little more lift out of them. (This will still allow the 3 wings to fit on a single sheet of foamboard)
It will be a few weeks before I have time to get Version 2 built, but I am hoping to get a few more flights out of version 1 this weekend and get some video of it.
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