After seeing this great looking plane in the magazine and on-line promotions, I decided to review the ParkZone Super Decathlon RTF plane. The covering scheme not only looked fantastic but it is just the right combination of colors that I love to see for great flying orientation!

You won't need anything to get this plane up and into the sky. ParkZone has included everything right in the box.

Here are the features of the Super Decathlon:

• Realistic features and scale appearance
• Proportional elevator, rudder, and throttle
• Mode-Change Flight Control System allows users to fly in two modes
• All components needed for flight are included in one box so you can get up and fly fast!
• Docile flight characteristics allow you to do large field moves within a small field of space
• Reusable 27 MHz proprietary radio system with Rx/speed control module and separate 5-wire servo motors
• One-piece wing with scale wing struts
• Gear-reduced 370 class motor with large propeller
• Stainless steel landing gear, including wheel pants
  

Wing Span: 35.4 in (900mm)
Overall Length: 25.3 in (640mm)
Flying Weight: 16oz (450g)
Motor Size: 370 class with gearbox
Radio: Proportional 3-channel FM
Trim Scheme Colors: Red Fuselage - Blue Trim with white borders
Recommended Battery: 8.4 V 600 mAh Ni-MH
Throttle: Proportional
Approx. Flying Duration: 13 minutes
Approx. Assembly Time: 5 minutes
Transmitter Range: 2500 feet (762m)
Available Frequencies: 6 Frequencies on 27 MHz
Smart Trak: No
X-Port: No
Charger: DC Peak
Landing Gear: Stainless steel with wheel pants

Everything you need is supplied in the box. This includes the RTF plane, transmitter, flight pack, peak charger, and support hardware. The box even includes AA-size batteries for the transmitter!

It takes longer to charge the 7-cell, 600mAh NiMH flight pack than it does to assemble the plane. I simply installed the eight AA batteries into the transmitter and then pushed on the pre-finished landing gear into the fuselage bottom.

The control linkage comes ready to go on the lowest throw setting. Since the transmitter has a dual-rate switch, I decided to increase the throw range by moving both the elevator and rudder clevises to the 3rd hole from the end of the control horns. The clevis was re-adjusted outward (by unscrewing it a few turns) to re-center the control surfaces after first centering the transmitter trim tabs.

A look around the fuselage reveals the radio components and geared power system

A look inside the fuselage reveals the radio components. The ESC is integrated with the receiver in an assembly that can be pulled up for changing the jumper settings. The Super Decathlon stock settings were what I wanted to use so no jumpers needed to be changed.

Jumper settings were provided for the following features:

Jumper 1- Mix of Elevator and Rudder:
You can add the jumper to utilize software that will allow a slight mix of elevator and rudder. In this mode, when rudder input is given, a slight amount of up elevator is added. By doing this, the nose of the airplane will be more likely to “stay up” when rudder input is given. This can be of great help to pilots that are transitioning from 2 to 3 channel aircraft and are not used to pitch control.

Jumper 2 - V-Tail/Standard Tail:
Tail control: Your Super Decathlon comes with the plane set for conventional “T” tail control. If you remove the jumper, you will switch the control to “V” tail function. This would allow you to transfer the radio system to a “V” tailed aircraft, such as the ParkZone™ Slo-V™, or elevon equipped aircraft such as the ParkZone™ F-27 Stryker™.

Jumper 3 - Auto Cutoff:
Auto Cut-Off: Your Super Decathlon comes with the jumper included in the third port. This sets the auto cut-off to function with 6-8 cell Ni-MH battery packs. If you remove the jumper, the auto cut-off will function with a 9 cell Ni-MH battery pack or a 3S LiPo battery pack.

When your Super Decathlon goes into auto cut-off, prepare to land immediately. You will maintain control of steering and pitch, but not have access to throttle at this time. You can “blip” the throttle to try to re-arm, but only attempt this once as you are preparing to land.

I was happy to see that the flight pack was positioned near the CG. This meant that a change in the pack weight by changing cell type or battery technology would have little impact on the balance.

Although the plane was suppose to weigh 16oz (flying weight), I measured 15.6oz for the empty plane and 3.6oz for the 7-cell, 600mAh NiMH pack. My plane weighed 19.2oz ready to fly. This additional 20% in weight could play a factor in how well the plane performed with a geared Speed 370 (aka Speed 300) power system.

My Super Decathlon was ready to fly before the battery finished charging. It looked great right out of the box and I was anxious to give it a test fly. The wing measured 35" by 6" so the wingarea was about 210 sq. in. The wingloading would be 19.2/(210/144) or 13oz/sq. ft. which is a bit high, but functional, for a geared Speed 300 plane.

Test Flight #1:

The maiden flight was on a cold grey day with temperatures around 35 degrees

I flew the Super Decathlon on a cold grey day with a moderate wind. The temperature was around 35 degrees F. The wind seemed to change directions and the speed was 5-15mph. Obviously, these conditions were less than desired.

On my maiden flight, I was both impressed and a bit disappointed. I was impressed that the plane flew straight with neutral trim settings on the control surfaces and transmitter trim tabs. Since most of the flight was at full power, I was a bit disappointed in the power system.

Although I knew that the plane would fly better under nicer weather conditions, I decided to investigate the power system.

Cowl Removal:

A single screw holds the cowl in place along with some double-sided tape on the sides

The prop removes easy by pulling off the spinner and unscrewing the nut. The cowl can be removed with a single screw after first peeling off the black sticker. The side decals must be either cut or peeled back. I choose to cut mine at the cowl edge. The cowl sides must be pulled out to break the hold of the double-sided tape.

The power system looked neat and easy to repair. Note that the motor is reversed so that it can still spin in the forward (CCW) direction in the gearbox. I thought this was a clever design overall.

A 0.1oz nut was wedged onto a plastic post in the front of the cowl. This was most likely a fine adjustment to the CG. Since my plane flew perfectly straight when the control surfaces were at neutral, I feel that ParkZone did a good job in both balancing the plane and obtaining the correct thrust angle.

I noticed that my prop was not perfectly balanced so I added a small piece of masking tape to the back side of one blade. This eliminated the "double vision" seen when watching the prop from the side at full throttle and also reduced the vibration felt from the fuselage.

Since I could not easily measure the current with the 7-cell, 600mAh NiMH pack, I decided to put the front end back together and give it another test flight. Perhaps I would see more power once the NiMH pack and gearbox had a few flights on them.

Test Flight #2:

I found a way to connect my watt meter using a series of adapters. The stock ParkZone connectors are not my normal choice for other planes.

The stock setup measured as follows using the 3.6oz, 600mAh, 7-cell pack:

• 5.8amps, 43 watts, stock prop (perhaps an 8x6)
• 5.8amps, 43 watts, GWS 9x4.7 SF prop
• 7.0amps, 47 watts, GWS 10x4.7 SF prop

In essense, the stock setup, although properly designed, is a bit low in power for this plane at 36 watts/lb. The change to a GWS 10x4.7 prop provides an additional 10% more power but also taxes the motor more. This may be ok due to in-flight unloading of about 10%.

I also tried a few 2-cell Lithium packs with the GWS 10x4.7 prop:

• 6.3amps, 40 watts using 3.0oz Kokam 1500mAh pack
• 6.3amps, 40 watts using 1.6oz ThunderPower 860mAh pack

Of the two Lithium packs I tested, the lighter weight ThunderPower pack reduces the flying weight by 2oz or about 11% at 17.2oz.

While the plane would certainly fly easier in a calm summer morning, the cold temperatures in a New England winter season put greater demands on the power system. Perhaps a GWS 10x8 prop combined with a lighter 2-cell Lithium pack would supply the easiest upgrade for increased power and reduced weight. The upgraded power system could deliver about 50 watts/lb. with a lighter wingloading.

My Super Decathlon sat on the frozen tundra of upstate NY waiting for better weather conditions. It was -1 degree F at the time and I wasn't about to test fly it with the larger GWS 10x4.7 SF prop until it got warmer.

Fortunately, the weekend weather was much better! It was 28 degrees outside with an easterly wind about 8-10mph. I had a relatively clear parking lot at work on the weekend, which was mostly snow free, so I ROG'ed it right from the pavement and easily cleared the 8' snow banks created from plowing earlier in the week.

I finally had a good time with my Super Decathlon! I took off into the wind with authority and I could throttle back for some cruising around. After flying for about 5 minutes, I decided to bring it in early so that I had enough power for a safety pull-out, if needed. I managed to land the plane right in the small parking lot without incident so I took a chance and ROG'd it a second time, again with no problem. After a few quick circles, I came in for a second near perfect landing. Landings seemed very easy by simply reducing throttle and watching the plane slowly descend into the parking lot area. As the plane approached the ground, I flared the elevator up a bit.

I didn't have any problem with ground clearance when using my 10x4.7 prop but the landing gear mains are a bit soft requiring a reasonably soft approach. Overall, I walked away pleased with the model and decided it was time to take some video.

Watch the video of the Super Decathlon
Windows media 5.57 MB	The video of me flying the Super Decathlon is stock except for the GWS 10x4.7 SF prop. Since the parking lot where I flew yesterday was loaded with cars, I had to hand toss it in the field across the street. The plane has sufficient power now in cold weather to fly and a reasonable flight time. We don't get much sun this time of year so I really enjoyed flying today!

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Power System Modification:

The stock motor was replaced with a Venom Fireball 370P motor

On a tip from a fellow RCU member, I decided to try a Venom VMG Fireball Micro 370P Motor from Tower Hobbies.

The new measurements with the Venom Fireball 370P motor show that it is only a slightly hotter wind. The construction looked similar to the stock Speed 300 motor although the Venom Fireball motor did have additional cooling vents in the case which cleared the stock gearbox. This should provide excellent cooling when pushing the motor for better performance.

The Venom Fireball setup measured as follows using the stock 3.6oz, 600mAh, 7-cell pack:

• 6.3amps, 47 watts, stock 8x4 prop
• 6.5amps, 47 watts, GWS 9x4.7 SF prop
• 7.7amps, 52 watts, GWS 9x7 SF prop

The motor swap did require the use of a pinion puller and some green Locktite to keep the original pinion gear on the new Fireball motor. This is not the easiest modification for people to attempt so I recommend caution. The result appears to be an increase of about 5 watts using a smaller GWS 9x7 prop which will help with ground clearance.

The ParkZone Super Decathlon is a great-looking model that comes in a complete Ready-To-Fly (RTF) package. The plane is RTF in less time than it takes to charge the battery. I did find the weight of the plane to be well over the manufacturer's specification. The additional 20% in weight, combined with the cold winter climate of upstate NY, created a marginal amount of power requiring full throttle for most of the flight. A simple prop change to a larger size produced much better results without undue stress on the motor. Additional modifications were tested and are listed below in order of simplicity.

• Swap stock 8x4 prop with 10x4.7 SF prop for 10% increase in power
• Swap stock 7-cell battery with 2-cell Lithium pack for 11% decrease in weight
• Swap stock motor with Venom Fireball 370P and 9x7 SF prop for a 21% increase in power

Although my model required a minor increase in power to fly well in cold weather conditions, I would recommend that you fly it stock first before considering any modifications. Whether airborne or on the ground, I love the look of my Super Decathlon! It flies well in a small field and transports easily when I see a good weather report in the morning before going to work.

The landing gear mains are a bit flexible requiring a soft landing. If they do get bent, it is easy to straighten them out and they can be removed from the fuselage with just a tug. The rest of the plane is very rugged and the wing struts prevent any warping in flight. The solid structure produces very stabile flight at both low and high speeds. Since the plane flies true to its scale heritage, I recommend it for intermediate to advanced fliers only. The Super Decathlon is a good way for seasoned pilots to enjoy a stress-free outing in the backyard or just down the street!

A Horizon Hobby, Inc. Brand
Horizon Hobby, Inc.
Champaign, IL 61822
Toll-Free: (800) 338-4639
www.parkzone.com

Horizon Hobby, Inc.
4105 Fieldstone Road
Champaign, IL 61822
Toll-Free: (800) 338-4639
www.horizonhobby.com