therotund1
Sep 24, 2004, 02:00 AM
!Introduction
| spec2
| @907667
|> <b>Model:</b> |< <a href=http://www.hobbypeople.net/gallery/126515.asp>Global's Super Decathlon 52</a>
|> <b>Wingspan:</b> |< 63"
|> <b>Wing Area:</b> |< 641 sq. in.
|> <b>Weight:</b> |< 5 lb. 15 oz.
|> <b>Length:</b> |< 45.5"
|> <b>Wing Loading:</b> |< 20-22 oz/sq. ft.
|> <b>Servos:</b> |< 5, Futaba S3001
|> <b>Transmitter:</b> |< Futaba 9CAF
|> <b>Receiver:</b> |< Futaba FP-R127DF
|> <b>Battery:</b> |< JR 1400MaH 4.8V NiCad
|> <b>Engine:</b> |< <a href=http://www.hobbypeople.net/gallery/210945.asp>Magnum XL.70RFS</a>
|> <b>Prop:</b> |< Master Airscrew 13-6 K Series
|> <b>Landing Gear:</b> |< As supplied
|> <b>Fuel Tank:</b> |< 260cc/8.79fl. oz., As supplied
|> <b>Hardware:</b> |< As supplied
|> <b>Hinges:</b> |< CA type, As supplied
|> <b>Manufacturer:</b> |< <a href=http://www.globalhobby.com>Global Hobby Distributors</a>
|> <b>Available From:</b> |< <a href=http://www.hobbypeople.net>Hobby People</a>
The Super Decathlon has been an airshow mainstay for a long time. You have probably seen one at one time or another and may not have noticed it because it looks like a normal, run of the mill, general aviation aircraft. Not so! The Super Decathlon is rated at positive 6 and negative 5 G's! That's some serious airplane we've got here!
My personal inspiration for this model was seeing Greg Koontz flying his full scale Super Decathlon at Skyfest 2003 in Jackson Tennessee. He specializes in low, low, in your face aerobatics that will make you gasp! His opening has been to roll inverted on takeoff with about twenty feet between the wingtip and the runway. I thought that was just too cool and had to try that with an RC model. You can view photo's at <a href=http://www.skyfest.us>Skyfest's website</a> and view Quicktime Movies of Mr. Koontz, in his "office", at <a href=http://www.gkairshows.com>Greg Koontz Airshows</a>.
!Kit Contents
@907668:The kit contents.
Global's Super Decathlon 52 came with an all built up airframe with iron-on covering. The covering was yellow, black and white in the traditional starburst scheme on top, with black and white "campaign stripes" on the bottom of the wing. It had a good quality fiberglass cowl and wheel pants along with clear plastic windows along with all the necessary hardware for completion.
*Extra goodies that you'll need are:
*2 twelve inch extensions
*A "Y" harness for the ailerons
*A 1.75 inch spinner
*A Pitt's style muffler (if using a 2 stroke engine)
*A fueling valve or fuel dot
!Assembly
First things first. If you're even remotely interested in building one of these, download and read the 40 page <a href=http://media.hobbypeople.net/manual/126515.pdf>assembly manual</a>. This was one of the best manuals I've ever seen. It was complete, logically laid out, understandable and very well illustrated. If you want to get to know this airplane, take the time and look over the manual.
!!Wing
The wing was in left and right halves that were joined with a short wing joiner and then epoxied together to make it one piece. The wing was held on to the fuselage with a centered "tang" in the front and two bolts at the rear. The ailerons were authentic "barn door" style rather than "strip" type. The aileron servos were mounted to hatches which then mounted into the bottom of the wing for a very neat and clean installation. There were four tubular, aluminum wing struts that got attached to hard points in the wing and a cross bar in the bottom of the fuselage. I believed these struts were functional due to the short wing joiner so don't be tempted to leave them off. And besides, they really looked cool!
!!Tail
The horizontal stabilizer also had the Starburst covering scheme on the top of it, but it was solid yellow on the bottom. It had independent elevators controlled by a "Y" type pushrod. The instructions told me to remove a post from the back of the fuselage, then slide in the stab, and then glue the post I removed back in. I test fitted the stabilizer by sliding it sideways into the slot before the elevators were hinged. The fit was perfect so I chose to epoxy it in this manner rather than cut the fuse and slide it in from behind. This method worked fine for me.
The vertical stabilizer was already built onto the fuselage so all I had to do was attach the counterbalanced rudder after the tailwheel was installed! WOW! That was easy!
!!Fuselage
This was where it got a little harder. The fuselage assembly was a little more labor intensive than most ARF's I've had. There was nothing very difficult about what was left up to the assembler, it just took time to do it; so I broke the steps into subgroups.
!!!Engine
The engine was mounted on independent beam type mounts that were adjustable. The blind nuts were factory mounted in the already fuel-proofed firewall. The firewall had right and down thrust already built into it. The recommended mounting position was 90 degrees with the cylinder head at the plane's 3 o'clock position. There was a limited amount of adjustment in these mounting beams. Magnum's XL70RFS was at the outer limit of the mount's adjustment range. The manual gave instructions on how to remove the blind nuts and fill the holes with wooden dowels should it be necessary to change to a different engine orientation. I installed mine as the factory set it up. I had to drill my own throttle pushrod hole depending the particular engine I was using. There was plenty of room around the fuel tank for the throttle rod. There was a little bit of good news about the engine mounting beams. There were four holes already made into the mounting beams to attach the engine. The Magnum XL70RFS lined up with two of them. Hey, that was two less holes that had to be drilled. I could live with that...
Global stated that the recommended engine sizes were .52 to .61 2 stroke and .70 to .91 4 stroke. Magnum's XL91RFS would physically not fit without mounting it inverted and re-doing the mounting setup. More on this in the concluding statement at the end of the article.
!!!Fuel Tank
The supplied tank was of good quality. I decided to use three lines on mine. Fuel feed, exhaust pressure and a dedicated fuel fill/drain line to be used with a fuel dot. The cowled engine made remote fueling a necessity. A Dubro type fueling valve would've worked just fine with a two line setup. I chose the fuel dot method out of personal preference.
!!!Landing Gear
The main landing gear was an aluminum dural type gear held on with four screws that go into factory installed blind nuts. The landing gear was very springy and felt a little weak. The gear mounted into a recessed slot on the bottom of the fuselage.
Warning! There was bare wood in this slot! The slot was too close to the exhaust stream for comfort so fuel proofing was needed. Rather than mixing up a little alcohol thinned epoxy for this job, I chose to paint this area black to match the covering on the bottom of the plane. The wheels, and wheel pants went together without incident and surprisingly easy.
The tailwheel was a standard wire type that slid into a hole I drilled in the rudder for steering. It had a metal strap to support it that screwed into the bottom of the fuselage. The instructions showed me how to bend the strap to get a good fit. I encountered some binding due to the bend in the strap but have not had any problems from it.
!!!Servo Tray
The instructions had me load the rudder, elevator and throttle servos into the servo tray before it was glued into the fuselage. This was a good thing to do because the rearmost servo screws ended up below the back of the wing saddle. It would be very difficult to get at these screws once the servo tray was installed.
!!!Pushrods
The pushrods were wire and balsa wood. These did not come preassembled. The instruction book was very clear on how to make the "Y" type elevator, and the single ended rudder pushrods. The manual instructed me to use the supplied heat shrink material to retain the epoxied wire to the balsa wood pushrod. I also wrapped mine with fishing line and another layer of epoxy for safety's sake. The supplied pushrod wire was a little on the "springy" side.
!!!Wing Strut Mount
Global included a small strap to mount the bottom of the wing struts to the fuselage. This strap was held in by two screws that went into wood blocks already installed in the fuselage floor. Great care needed to be used in drilling these screw holes. There was a possibility of drilling through the bottom covering if they were drilled too deep. A long drill bit or a pin vise drill would be needed for this job as these blocks were right up against the fuselage sides. There simply wasn't enough room for a standard length bit and drill to get in there properly. To keep from drilling too deep, I used a piece of electrical tape wrapped around the bit as a guide to let me know when to stop. It was a simple method and worked well.
!!!Cowl
The cowl was a little bit of a chore to get right due to the size of the Magnum XL70RFS. First, I opened up the cooling holes in the cowl and roughed in the engine clearance holes. Then I had to shave the upper engine mounting beam to get the cowl to go down far enough to center on the engine's crankshaft. Once I got the engine's clearance holes fitting well, I drilled the holes to mount the cowl to the fuselage. There is tri stock behind the firewall for the screws to seat into. This was by far the single most time consuming part of this model. I removed and re-installed the engine and cowl six times before I got it the way I wanted it. But, I was being very careful with it. I considered the effort well spent on the cowl because, if too much material was removed for clearance, it couldn't be put back. I mounted a fuel dot in the left side of the cowl but, in retrospect, I should have mounted it in the lower front of the cowl where there is a recess molded in for a landing light. I could have even glued a simulated headlight lens on the fuel dot!
!!!Windows
There were four precut, flat side windows and a windshield that needed to be cut out for cabin glass on this model. The side windows simply popped in and had a ledge to glue them to. No trimming was necessary on these windows and the fit was perfect! The windshield was also to be glued in after trimming, but, I chose to mount it with four servo screws instead. I did that in case I ever had to service the pushrods. The only other way to get the pushrods out, if need be, would be to remove the cowl, engine and fuel tank, and slide the pushrods out through the fuel tank hole in the firewall.
Warning! Leave the windows out of the model until after everything is done inside the plane. The window holes offer extra access to the inside of the plane.
!!Radio Installation
I mounted my switch and charge jack on the left side below the side window for ease of access. The switch and charge jack could have been easily camouflaged if installed on the black part of the covering. I then hooked up all of the fuselage servos and electronically centered them and adjusted the servo arms. At this time, I marked and bent the servo end of the pushrods at ninety degrees. I removed the pushrods to do this. It was easier, trust me.(A quick tip on getting the pushrods through the slots at the rear of the fuselage.) I slid some spare plastic pushrod tubing through the exit holes toward the front of the plane, then I slid the threaded end of the plane's rigid pushrod into the plastic tubes, then slid everything to the rear. The plastic tubing acted as a guide and took a frustrating job and made it easy. I routed my receiver antenna out the bottom of the plane behind the landing gear. At this point I left the battery and reciever loose in the plane to do a "pre-balance" on it. This was done to determine the final location of these components so as to be able to shift them around to achieve proper balance without adding lead weight. The center of gravity was achieved by mounting the battery under the front edge of the servo tray and the receiver immediately in front of the battery. I then secured battery and receiver with some scrap balsa sticks.
@907669:The interior
!!Completion
The center of gravity was 2-7/8" from the leading edge of the wing. Mine balanced perfectly! Dead on it! That's never happened before.... I set up triple rates on mine with low rates as recommended by Global.
*Low rates:
*Ailerons: 3/8" up/down
*Elevator: 3/8" up/down
*Rudder: 3/4" left/right
Now guess what? The payoff! It's time to fly!
!!!Posing Time
@907670:Ready to fly
@907671:Front
@907667:Left Front
@907672:Left Rear
@907673:Rear
@907674:Right Rear
@907675:Right Front
@907676:Engine
!Flying
This flight session had two "firsts" going for it and one against it. The first flight on the Super Decathlon 52, the first time flying at the field in Dyer Tennessee, and the first time I've ever flown a plane into a tree! (No, it wasn't the Decathlon!)
!!Pre-Flight
After taking photos of the plane, I checked the control directions, fueled it, and fired it up! The plane handled well on the ground but the slightly weak landing gear let it rock from side to side. It tracked very well on the ground even through thick grass (but it did need some throttle to get moving.) And it looked just fantastic!
@907677:Taxiing out
!!Taking Off
The moment of truth... I had a few butterflies... I had heard horror stories about planes like this... Well, it was time... I fed in the throttle slowly to be sure it didn't ground loop on me and gave it a little burst of speed when it was solidly tracking down the runway for insurance. A beep of up trim and two beeps of left were all that it needed. I had those butterflies for no reason. Take off was tail high and easy!
!!Aerobatics/Special Flight Performance
The flight characteristics of this plane were very, very good. Stalls were straight forward with no tendency to drop a wing. Any increase in airspeed and it was flying again. Very nice. At speed it flew like it was on rails. It went anywhere I pointed it. It was one of those planes that didn't have a mind of it's own, meaning it didn't wander around making you chase it. The plane "felt" light. Flying at the recommended control rates was very docile, relaxing even. On higher rates, the Decathlon perked right up! Rolls were not wobbly but did have a little bit of altitude drop. Loops were tight, but not funfly tight. They looked right for the plane. Inverted flight required some down elevator but not overly so. It was easily controlled while inverted.
@907678:Slow flying down low
@907679:And a little lower
@907680:Even lower
Snap rolls were this plane's bag. This plane really got wound up! Getting it to stop didn't require you to either have excellent timing or use the controls to stop it. If left on it's own it would stop snapping in about 1/2 of a revolution. Single snap rolls were very cool and lose very little altitude if any. Left snaps were quicker than right snaps.
@907681:"Campaign Stripes"
@907682:Fly over
@907683:Glory shot!
Knife edge flight had some coupling toward the wing but was easily controlled. The rudder was extremely powerful on this plane and climbing while in knife edge flight was actually easy.
@907684:Knife edge
Spins were scale like at about 45 degrees nose down, either upright or inverted. The plane did take some time to come out of a spin on it's own, so be aware of your altitude. Flying out of a spin was no problem at all.
@907685:In the air
@907686:Looking good
@907687:Looking real good
Slow flight was very relaxing even on high rates. This plane flew at a trainer-like pace with full control.
@907688:Ahhhhh....
!!Landing
@907689:Approach for landing
@907690:Touchdown!
There was one thing that this plane has done for me. It taught me how to do a proper main gear tail up landing. I've never been able to do that. The Decathlon did not like three point, full stall type landings. The angle of attack made it too high for three pointers. It could be done, but it made you work for it. I'm so tickled that I can now land on the mains, properly, that I don't even attempt the tail down landings anymore with this plane. The plane really made it easy. The weak landing gear was not an issue unless I really bounced it hard. I've only had to straighten it once because, in the failing light, I landed about a foot above the runway. PLOP! It was no problem to bend it back and has retained it's shape just fine.
@907691:Taxiing back in
!!Is This For a Beginner?
Well, this get's a yes and a maybe.
!!!The yes
The flight performance was very suitable for an advancing beginner who could handle flying a tail dragger. The rudder work on takeoff and landing was not excessive at all, but it still needed some input. Once it was in the air on even the middle rates, it was easily controlled. It flew so solidly that it actually inspired confidence. The only non-trainer flight characteristic it had is a lack of self recovery. It wouldn't just roll upright and keep flying on it's own. The ease of flying this plane outweighed the self recovery issue in my book.
!!!The maybe
The assembly process had a lot of items you have to do that may cause you to get frustrated. It was a time consuming plane to put together. As I said earlier, there was nothing very difficult about any of it other than the effort you have to put into it. Having an experienced modeler to assist you would help a lot. Read the assembly manual and if you're comfortable with all of the steps then the assembly process could be for a beginner as well.
!!Flight Video
+907692:The Decathlon's maiden flight.
+907693:Getting a feel for the Decathlon.
!!Recommendations
After flying this plane extensively, only two problems have shown up.
The wheel pants had no anti-rotation provision as supplied. One of mine rolled over and turned into a mini-float after the twentieth flight. I recommend drilling through the main gear and the wheel pant to mount a 4-40 blind nut in the wood reinforcement on the pant and bolting it to the main gear as well as the factory set up.
The wing struts loosened up at the wing even after hardening the mounting block with CA. I would recommend actually using epoxy to keep the screws in place on the wing side of the strut connections. I also replaced the lower strut mounting nuts (at the cross strap) with nylon lock nuts.
*The good stuff
*Great covering scheme.
*Easy to see in the air.
*Wonderful flight.
*Classic looks.
*Assembly manual.
*Does not need the power of the Magnum XL91RFS.
*The not so good stuff
*Tailwheel.
*Labor intensive assembly.
*Magnum's XL91RFS will not physically fit without reworking the mounting style.
*No anti-rotation provision for the wheel pants.
!Conclusion
Overall, Global has done a good job on this ARF. The wide flight envelope far outweighed the assembly time. In plain English, this plane was worth the effort!
But assembly WAS tedious. Even <b>I</b> got discouraged at the time involved to assemble it...it took me around 25 hours. Admittedly, I am slow, but not that slow.
Those that were with me at the first flight can attest in my "attitude adjustment" towards this plane after I landed. It flew so much better than I expected that I was amazed. It flew light, straight and true. Global had recommended the engine sizes up to a .61 2 stroke and a .91 4 stroke. These large engines were simply not needed. I believe it will perform well with a .40ish bearing engine or a .52 4 stroke. Magnum's new XL.70RFS is already more than it needs to have unlimited vertical and it continues to impress me every time I fly it. This plane's characteristics will ensure a long hangar life exploring scale, pattern, barnstorming and relaxing flying styles. As long as you are not a 3D die hard, Global's Super Decathlon 52 is a plane for all seasons.
@907670:It's a keeper!
!On a personal note
In the introduction, I stated that I wanted to do Greg Koontz's full size show opening move. I have successfully done it and it feels good! I am now attempting to duplicate his entire routine. What fun!
Special thanks to Don Sims, Donny Lyons and Woody Workman for video, camera duties and support. Thanks guys!
| spec2
| @907667
|> <b>Model:</b> |< <a href=http://www.hobbypeople.net/gallery/126515.asp>Global's Super Decathlon 52</a>
|> <b>Wingspan:</b> |< 63"
|> <b>Wing Area:</b> |< 641 sq. in.
|> <b>Weight:</b> |< 5 lb. 15 oz.
|> <b>Length:</b> |< 45.5"
|> <b>Wing Loading:</b> |< 20-22 oz/sq. ft.
|> <b>Servos:</b> |< 5, Futaba S3001
|> <b>Transmitter:</b> |< Futaba 9CAF
|> <b>Receiver:</b> |< Futaba FP-R127DF
|> <b>Battery:</b> |< JR 1400MaH 4.8V NiCad
|> <b>Engine:</b> |< <a href=http://www.hobbypeople.net/gallery/210945.asp>Magnum XL.70RFS</a>
|> <b>Prop:</b> |< Master Airscrew 13-6 K Series
|> <b>Landing Gear:</b> |< As supplied
|> <b>Fuel Tank:</b> |< 260cc/8.79fl. oz., As supplied
|> <b>Hardware:</b> |< As supplied
|> <b>Hinges:</b> |< CA type, As supplied
|> <b>Manufacturer:</b> |< <a href=http://www.globalhobby.com>Global Hobby Distributors</a>
|> <b>Available From:</b> |< <a href=http://www.hobbypeople.net>Hobby People</a>
The Super Decathlon has been an airshow mainstay for a long time. You have probably seen one at one time or another and may not have noticed it because it looks like a normal, run of the mill, general aviation aircraft. Not so! The Super Decathlon is rated at positive 6 and negative 5 G's! That's some serious airplane we've got here!
My personal inspiration for this model was seeing Greg Koontz flying his full scale Super Decathlon at Skyfest 2003 in Jackson Tennessee. He specializes in low, low, in your face aerobatics that will make you gasp! His opening has been to roll inverted on takeoff with about twenty feet between the wingtip and the runway. I thought that was just too cool and had to try that with an RC model. You can view photo's at <a href=http://www.skyfest.us>Skyfest's website</a> and view Quicktime Movies of Mr. Koontz, in his "office", at <a href=http://www.gkairshows.com>Greg Koontz Airshows</a>.
!Kit Contents
@907668:The kit contents.
Global's Super Decathlon 52 came with an all built up airframe with iron-on covering. The covering was yellow, black and white in the traditional starburst scheme on top, with black and white "campaign stripes" on the bottom of the wing. It had a good quality fiberglass cowl and wheel pants along with clear plastic windows along with all the necessary hardware for completion.
*Extra goodies that you'll need are:
*2 twelve inch extensions
*A "Y" harness for the ailerons
*A 1.75 inch spinner
*A Pitt's style muffler (if using a 2 stroke engine)
*A fueling valve or fuel dot
!Assembly
First things first. If you're even remotely interested in building one of these, download and read the 40 page <a href=http://media.hobbypeople.net/manual/126515.pdf>assembly manual</a>. This was one of the best manuals I've ever seen. It was complete, logically laid out, understandable and very well illustrated. If you want to get to know this airplane, take the time and look over the manual.
!!Wing
The wing was in left and right halves that were joined with a short wing joiner and then epoxied together to make it one piece. The wing was held on to the fuselage with a centered "tang" in the front and two bolts at the rear. The ailerons were authentic "barn door" style rather than "strip" type. The aileron servos were mounted to hatches which then mounted into the bottom of the wing for a very neat and clean installation. There were four tubular, aluminum wing struts that got attached to hard points in the wing and a cross bar in the bottom of the fuselage. I believed these struts were functional due to the short wing joiner so don't be tempted to leave them off. And besides, they really looked cool!
!!Tail
The horizontal stabilizer also had the Starburst covering scheme on the top of it, but it was solid yellow on the bottom. It had independent elevators controlled by a "Y" type pushrod. The instructions told me to remove a post from the back of the fuselage, then slide in the stab, and then glue the post I removed back in. I test fitted the stabilizer by sliding it sideways into the slot before the elevators were hinged. The fit was perfect so I chose to epoxy it in this manner rather than cut the fuse and slide it in from behind. This method worked fine for me.
The vertical stabilizer was already built onto the fuselage so all I had to do was attach the counterbalanced rudder after the tailwheel was installed! WOW! That was easy!
!!Fuselage
This was where it got a little harder. The fuselage assembly was a little more labor intensive than most ARF's I've had. There was nothing very difficult about what was left up to the assembler, it just took time to do it; so I broke the steps into subgroups.
!!!Engine
The engine was mounted on independent beam type mounts that were adjustable. The blind nuts were factory mounted in the already fuel-proofed firewall. The firewall had right and down thrust already built into it. The recommended mounting position was 90 degrees with the cylinder head at the plane's 3 o'clock position. There was a limited amount of adjustment in these mounting beams. Magnum's XL70RFS was at the outer limit of the mount's adjustment range. The manual gave instructions on how to remove the blind nuts and fill the holes with wooden dowels should it be necessary to change to a different engine orientation. I installed mine as the factory set it up. I had to drill my own throttle pushrod hole depending the particular engine I was using. There was plenty of room around the fuel tank for the throttle rod. There was a little bit of good news about the engine mounting beams. There were four holes already made into the mounting beams to attach the engine. The Magnum XL70RFS lined up with two of them. Hey, that was two less holes that had to be drilled. I could live with that...
Global stated that the recommended engine sizes were .52 to .61 2 stroke and .70 to .91 4 stroke. Magnum's XL91RFS would physically not fit without mounting it inverted and re-doing the mounting setup. More on this in the concluding statement at the end of the article.
!!!Fuel Tank
The supplied tank was of good quality. I decided to use three lines on mine. Fuel feed, exhaust pressure and a dedicated fuel fill/drain line to be used with a fuel dot. The cowled engine made remote fueling a necessity. A Dubro type fueling valve would've worked just fine with a two line setup. I chose the fuel dot method out of personal preference.
!!!Landing Gear
The main landing gear was an aluminum dural type gear held on with four screws that go into factory installed blind nuts. The landing gear was very springy and felt a little weak. The gear mounted into a recessed slot on the bottom of the fuselage.
Warning! There was bare wood in this slot! The slot was too close to the exhaust stream for comfort so fuel proofing was needed. Rather than mixing up a little alcohol thinned epoxy for this job, I chose to paint this area black to match the covering on the bottom of the plane. The wheels, and wheel pants went together without incident and surprisingly easy.
The tailwheel was a standard wire type that slid into a hole I drilled in the rudder for steering. It had a metal strap to support it that screwed into the bottom of the fuselage. The instructions showed me how to bend the strap to get a good fit. I encountered some binding due to the bend in the strap but have not had any problems from it.
!!!Servo Tray
The instructions had me load the rudder, elevator and throttle servos into the servo tray before it was glued into the fuselage. This was a good thing to do because the rearmost servo screws ended up below the back of the wing saddle. It would be very difficult to get at these screws once the servo tray was installed.
!!!Pushrods
The pushrods were wire and balsa wood. These did not come preassembled. The instruction book was very clear on how to make the "Y" type elevator, and the single ended rudder pushrods. The manual instructed me to use the supplied heat shrink material to retain the epoxied wire to the balsa wood pushrod. I also wrapped mine with fishing line and another layer of epoxy for safety's sake. The supplied pushrod wire was a little on the "springy" side.
!!!Wing Strut Mount
Global included a small strap to mount the bottom of the wing struts to the fuselage. This strap was held in by two screws that went into wood blocks already installed in the fuselage floor. Great care needed to be used in drilling these screw holes. There was a possibility of drilling through the bottom covering if they were drilled too deep. A long drill bit or a pin vise drill would be needed for this job as these blocks were right up against the fuselage sides. There simply wasn't enough room for a standard length bit and drill to get in there properly. To keep from drilling too deep, I used a piece of electrical tape wrapped around the bit as a guide to let me know when to stop. It was a simple method and worked well.
!!!Cowl
The cowl was a little bit of a chore to get right due to the size of the Magnum XL70RFS. First, I opened up the cooling holes in the cowl and roughed in the engine clearance holes. Then I had to shave the upper engine mounting beam to get the cowl to go down far enough to center on the engine's crankshaft. Once I got the engine's clearance holes fitting well, I drilled the holes to mount the cowl to the fuselage. There is tri stock behind the firewall for the screws to seat into. This was by far the single most time consuming part of this model. I removed and re-installed the engine and cowl six times before I got it the way I wanted it. But, I was being very careful with it. I considered the effort well spent on the cowl because, if too much material was removed for clearance, it couldn't be put back. I mounted a fuel dot in the left side of the cowl but, in retrospect, I should have mounted it in the lower front of the cowl where there is a recess molded in for a landing light. I could have even glued a simulated headlight lens on the fuel dot!
!!!Windows
There were four precut, flat side windows and a windshield that needed to be cut out for cabin glass on this model. The side windows simply popped in and had a ledge to glue them to. No trimming was necessary on these windows and the fit was perfect! The windshield was also to be glued in after trimming, but, I chose to mount it with four servo screws instead. I did that in case I ever had to service the pushrods. The only other way to get the pushrods out, if need be, would be to remove the cowl, engine and fuel tank, and slide the pushrods out through the fuel tank hole in the firewall.
Warning! Leave the windows out of the model until after everything is done inside the plane. The window holes offer extra access to the inside of the plane.
!!Radio Installation
I mounted my switch and charge jack on the left side below the side window for ease of access. The switch and charge jack could have been easily camouflaged if installed on the black part of the covering. I then hooked up all of the fuselage servos and electronically centered them and adjusted the servo arms. At this time, I marked and bent the servo end of the pushrods at ninety degrees. I removed the pushrods to do this. It was easier, trust me.(A quick tip on getting the pushrods through the slots at the rear of the fuselage.) I slid some spare plastic pushrod tubing through the exit holes toward the front of the plane, then I slid the threaded end of the plane's rigid pushrod into the plastic tubes, then slid everything to the rear. The plastic tubing acted as a guide and took a frustrating job and made it easy. I routed my receiver antenna out the bottom of the plane behind the landing gear. At this point I left the battery and reciever loose in the plane to do a "pre-balance" on it. This was done to determine the final location of these components so as to be able to shift them around to achieve proper balance without adding lead weight. The center of gravity was achieved by mounting the battery under the front edge of the servo tray and the receiver immediately in front of the battery. I then secured battery and receiver with some scrap balsa sticks.
@907669:The interior
!!Completion
The center of gravity was 2-7/8" from the leading edge of the wing. Mine balanced perfectly! Dead on it! That's never happened before.... I set up triple rates on mine with low rates as recommended by Global.
*Low rates:
*Ailerons: 3/8" up/down
*Elevator: 3/8" up/down
*Rudder: 3/4" left/right
Now guess what? The payoff! It's time to fly!
!!!Posing Time
@907670:Ready to fly
@907671:Front
@907667:Left Front
@907672:Left Rear
@907673:Rear
@907674:Right Rear
@907675:Right Front
@907676:Engine
!Flying
This flight session had two "firsts" going for it and one against it. The first flight on the Super Decathlon 52, the first time flying at the field in Dyer Tennessee, and the first time I've ever flown a plane into a tree! (No, it wasn't the Decathlon!)
!!Pre-Flight
After taking photos of the plane, I checked the control directions, fueled it, and fired it up! The plane handled well on the ground but the slightly weak landing gear let it rock from side to side. It tracked very well on the ground even through thick grass (but it did need some throttle to get moving.) And it looked just fantastic!
@907677:Taxiing out
!!Taking Off
The moment of truth... I had a few butterflies... I had heard horror stories about planes like this... Well, it was time... I fed in the throttle slowly to be sure it didn't ground loop on me and gave it a little burst of speed when it was solidly tracking down the runway for insurance. A beep of up trim and two beeps of left were all that it needed. I had those butterflies for no reason. Take off was tail high and easy!
!!Aerobatics/Special Flight Performance
The flight characteristics of this plane were very, very good. Stalls were straight forward with no tendency to drop a wing. Any increase in airspeed and it was flying again. Very nice. At speed it flew like it was on rails. It went anywhere I pointed it. It was one of those planes that didn't have a mind of it's own, meaning it didn't wander around making you chase it. The plane "felt" light. Flying at the recommended control rates was very docile, relaxing even. On higher rates, the Decathlon perked right up! Rolls were not wobbly but did have a little bit of altitude drop. Loops were tight, but not funfly tight. They looked right for the plane. Inverted flight required some down elevator but not overly so. It was easily controlled while inverted.
@907678:Slow flying down low
@907679:And a little lower
@907680:Even lower
Snap rolls were this plane's bag. This plane really got wound up! Getting it to stop didn't require you to either have excellent timing or use the controls to stop it. If left on it's own it would stop snapping in about 1/2 of a revolution. Single snap rolls were very cool and lose very little altitude if any. Left snaps were quicker than right snaps.
@907681:"Campaign Stripes"
@907682:Fly over
@907683:Glory shot!
Knife edge flight had some coupling toward the wing but was easily controlled. The rudder was extremely powerful on this plane and climbing while in knife edge flight was actually easy.
@907684:Knife edge
Spins were scale like at about 45 degrees nose down, either upright or inverted. The plane did take some time to come out of a spin on it's own, so be aware of your altitude. Flying out of a spin was no problem at all.
@907685:In the air
@907686:Looking good
@907687:Looking real good
Slow flight was very relaxing even on high rates. This plane flew at a trainer-like pace with full control.
@907688:Ahhhhh....
!!Landing
@907689:Approach for landing
@907690:Touchdown!
There was one thing that this plane has done for me. It taught me how to do a proper main gear tail up landing. I've never been able to do that. The Decathlon did not like three point, full stall type landings. The angle of attack made it too high for three pointers. It could be done, but it made you work for it. I'm so tickled that I can now land on the mains, properly, that I don't even attempt the tail down landings anymore with this plane. The plane really made it easy. The weak landing gear was not an issue unless I really bounced it hard. I've only had to straighten it once because, in the failing light, I landed about a foot above the runway. PLOP! It was no problem to bend it back and has retained it's shape just fine.
@907691:Taxiing back in
!!Is This For a Beginner?
Well, this get's a yes and a maybe.
!!!The yes
The flight performance was very suitable for an advancing beginner who could handle flying a tail dragger. The rudder work on takeoff and landing was not excessive at all, but it still needed some input. Once it was in the air on even the middle rates, it was easily controlled. It flew so solidly that it actually inspired confidence. The only non-trainer flight characteristic it had is a lack of self recovery. It wouldn't just roll upright and keep flying on it's own. The ease of flying this plane outweighed the self recovery issue in my book.
!!!The maybe
The assembly process had a lot of items you have to do that may cause you to get frustrated. It was a time consuming plane to put together. As I said earlier, there was nothing very difficult about any of it other than the effort you have to put into it. Having an experienced modeler to assist you would help a lot. Read the assembly manual and if you're comfortable with all of the steps then the assembly process could be for a beginner as well.
!!Flight Video
+907692:The Decathlon's maiden flight.
+907693:Getting a feel for the Decathlon.
!!Recommendations
After flying this plane extensively, only two problems have shown up.
The wheel pants had no anti-rotation provision as supplied. One of mine rolled over and turned into a mini-float after the twentieth flight. I recommend drilling through the main gear and the wheel pant to mount a 4-40 blind nut in the wood reinforcement on the pant and bolting it to the main gear as well as the factory set up.
The wing struts loosened up at the wing even after hardening the mounting block with CA. I would recommend actually using epoxy to keep the screws in place on the wing side of the strut connections. I also replaced the lower strut mounting nuts (at the cross strap) with nylon lock nuts.
*The good stuff
*Great covering scheme.
*Easy to see in the air.
*Wonderful flight.
*Classic looks.
*Assembly manual.
*Does not need the power of the Magnum XL91RFS.
*The not so good stuff
*Tailwheel.
*Labor intensive assembly.
*Magnum's XL91RFS will not physically fit without reworking the mounting style.
*No anti-rotation provision for the wheel pants.
!Conclusion
Overall, Global has done a good job on this ARF. The wide flight envelope far outweighed the assembly time. In plain English, this plane was worth the effort!
But assembly WAS tedious. Even <b>I</b> got discouraged at the time involved to assemble it...it took me around 25 hours. Admittedly, I am slow, but not that slow.
Those that were with me at the first flight can attest in my "attitude adjustment" towards this plane after I landed. It flew so much better than I expected that I was amazed. It flew light, straight and true. Global had recommended the engine sizes up to a .61 2 stroke and a .91 4 stroke. These large engines were simply not needed. I believe it will perform well with a .40ish bearing engine or a .52 4 stroke. Magnum's new XL.70RFS is already more than it needs to have unlimited vertical and it continues to impress me every time I fly it. This plane's characteristics will ensure a long hangar life exploring scale, pattern, barnstorming and relaxing flying styles. As long as you are not a 3D die hard, Global's Super Decathlon 52 is a plane for all seasons.
@907670:It's a keeper!
!On a personal note
In the introduction, I stated that I wanted to do Greg Koontz's full size show opening move. I have successfully done it and it feels good! I am now attempting to duplicate his entire routine. What fun!
Special thanks to Don Sims, Donny Lyons and Woody Workman for video, camera duties and support. Thanks guys!