EXCLUSIVE interview with Charlie Hua, Ultrafly Models, at Toledo 2004

Pat Mattes' exclusive interview with Charlie Hua, general manager, UltraFly Corporation, an electric-powered model manufacturer newly distributed by Great Planes Model Distributors into the US! Includes video of the new releases, ***AND*** of several upcoming projects!

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With few exceptions, I have attended nearly every annual Toledo R/C Exposition for over 20 years. And every time I leave there after the weekend, I’m already looking forward to the next year’s show before I even get home! The last 5 years or so at Toledo has been monumental in showcasing the latest technologies and availability of electric propulsion systems. The electric facet of the hobby shows no sign of tapering off, and in fact continues to experience exponential increases in power systems, kits, and accessories. At one time it was almost easy to digest all the available information and stay “ahead of the curve”, but recently that has become nearly impossible. To be an expert in any one field, you have to break it down to finer segments than normal just to keep up with the rampant progress being made, whether that be in construction materials, motor types, or the latest battery technology. My point is that it has become nearly impossible for anyone to be a total electric expert anymore due to the wide proliferation and diversification of that facet of the hobby. The growth is astounding.

That being said, I had a special opportunity at this show, and wanted to share it with you all. At the 2004 Toledo show Great Planes had several new electric planes that really caught my attention. The looks alone were enough to draw me closer, but there’s more than just looks behind a good plane. I happened to be at the right place at the right time, asking many questions about the models on display. While there I was introduced to Charlie Hua, the General Manager of UltraFly Model Corporation. Great Planes will be distributing models from UltraFly later this Spring, such as the stunning renditions of a Navy T-45 Goshawk (BAE Hawk) and the Swiss Air Force PC-7 by Pilatus. Also displayed was the Cessna 182, which is a beautiful craft as well and has some great features such as a beginner wing and an advanced wing with the kit, allowing greater functionality.

Charlie and I talked at length at the show, and I wanted to cover the background of UltraFly Model Corporation and the design methodology behind these three aircraft and several others in the works. Charlie had 20 years experience in the Information Technology field, and wanted to branch out into different possibilities. He formed UltraFly Model Corporation on May 1st, 2003.

Selecting the Market

Charlie and his development team started doing market research on Ready to Fly electric models to better determine what the availability in the market was, and how the needs of the modelers were being met, or conversely, not being met. After benchmarking countless models in the size range they wanted to compete in, they started compiling a list of attributes to measure against, and began to strategize how to achieve them. Through this benchmarking they determined there was too much competition in the balsa ARF market, and felt their focus should be where they could have the highest impact, namely the injection molded foam ARF market. The advantages of injection molded foam over balsa constructed ARF’s or even site-cut EPP or EPS foam ARF’s was that injection molding provided a consistent quality that was locked in from the first kit to the last. It also allowed for far more complex shapes and an inherent ability to be more true-to-scale. Foam aircraft are more accommodating to harder landings, and in the event of a truly hard landing or even a healthy crash, they are often fairly easy to repair.

Charlie and his team continued to tighten their focus, and looked deeply into the marketing of today’s electric ARF class of RC planes. They began asking themselves the questions any company should: what price range does the market bear? What is the buyers experience level? What product strategies and offerings should they develop? What product strategies do their competitors have? What design goals should each aircraft offering have? And so they went to work.

The vision they formed for UltraFly Model Corporation would be thus:
Target Market:Intermediate to advanced pilot
Product Line:Injection Molded EPS foam '400' park fliers
Pricing:$85-100 US/ $95-110 European/Japanese
Customer Expectations:Determine from competitive products, and exceed them!

So with that vision in mind, the first task was to set design goals for each aircraft to be offered.

Charlie and his design team felt their product line should fall within these criteria:
Flying Weight:450-750 g
Motor:Mabuchi 380class motor (special wind)
Gearing Options:1.9, 2.4, 3.0, 3.9:1
Cell Count:8-10 NiMH 1100mAh cells

Throughout their benchmarking activities, UltraFly felt the largest weakness in most of the foam ARF aircraft available was lack of power. Current offerings were typically in the range of 60-70 watts for a 1-meter wingspan plane. Charlie felt the target should be at least 100 watts. His team wanted to develop park-flyer sized models in the 75cm to 120cm wingspan, with the appropriate amount of power available.

But increasing the variety of aircraft available also meant increasing the number of motor systems, and optimization would be difficult to maintain. Charlie felt that through the proper development of a single motor, proper gearing and propeller options, the optimization of the motor system could be maintained and still be used in a variety of aircraft. This helped dramatically with PowerPoint standardization, too. Sort of a “one size fits all” mentality!

The Products

At this point in the discussion Charlie fired up his laptop, and said he had something to show me. He loaded digital movies of each of the three planes on display at the Great Planes booth (immediately below this paragraph!). His emphasis on trying to develop a good power combination was evident! The Cessna 182 certainly flew very well, and having two different wings and the option of different power consumption for each version was a nice addition. The PC-7 certainly didn’t perform like your “typical” foam ARF; it had great flying characteristics and flew with authority. But most impressive of all was the video of the BAE Hawk. Putting 10 cells against a 400 sized motor, utilizing a gearbox, and then running a 6x5.5 prop sounds like a hop-up mod you would read about in a magazine, not the standard setup! The result is a beautiful little jet that flies like one too. It is rock steady in flight, and powers through large loops with ease. It screamed by the camera on its many passes down the runway, and effortlessly pulled away each time. And this was done at 9 amps? Power, speed, and duration, all at once! All these videos were fun to watch.


Charlie graciously also provided us video previews of products planned for near-term introduction from UltraFly Model Corporation:


And a list of a few of the other future products, sorry, but no video yet...

  • Ultimate 3D.
  • Glider(s) and a flying wing design.


Charlie was very personable to talk to throughout our interview, and he spoke with an evident enthusiasm about the hobby and what he felt UltraFly Models would be bringing to the market. In years past it was the customers who tweaked (or downright replaced!) the power systems available or recommended for electric airplanes. More recently, that same knowledge and optimization of power systems is now coming from the manufacturers themselves, which is good to see. No longer will first-time electric airplane owners consider electrics to have “lackluster” performance. The development of better power systems, and equally as important, the proper application of those systems, continues to push this facet of the RC hobby in a positive direction. And that paired up with novel, unique models to put those systems in brings forth exciting new horizons.

My hopes are that the dedication demonstrated by UltraFly to bring this kind of product into the marketplace not only meets with overwhelming success in the electric RC industry, but also drives them from a “new” company clear up to the ranks of being a household name!

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May 03, 2004, 11:41 PM
hweird's Avatar
Do you have Ultrafly's web site address? Very interesting discussion. I like their research into the market. Sounds like their listening to the kit bashers on the Zone and ending up with better flying models.
May 04, 2004, 02:46 AM
RC Player
Hi Howard,

The Web is under construction and will be available when our product get into US market. There will be a lot info after it is ready!


May 04, 2004, 11:19 AM
hweird's Avatar
Thank you Charlie!

Looking forward to seeing the site. The planes look great.

Are the Ultrafly brushless motors being advertised by Aircraft World (http://aircraft-world.com/shopexd.asp?id=2045) also your product? When will these be available? What competitive differentiators does it have? Looks like just another brushless motor similar to a MP-jet or Himax. Odd that it is described as a geared outrunner.
May 04, 2004, 07:26 PM
RC Player
Yes, the motor is from our company! We put a carbon housing around the small outrunner and offer a gearbox together. It comes with 1.9, 2.38, 3 & 3.9 four ratio for user to change and fit form most of the present park flyers under 1 kg. Visit the below thread.


May 04, 2004, 08:04 PM
Insert Witty Comment
Suntzu's Avatar
I started that Ultrafly thread. Also, I was one of the first to buy (AC WORLD) and test the ultrafly 30/24 in geared and direct drive format. Its a great little motor. I want to get another one for twin direct drive for a P38. Im glad I took the plunge on an unknown e-rc manufacturer.

I thought Charlie2020 might have worked for Ultrafly as he was the only one with Data on these motors. Great to see a manufacturer actively involved in the forum here.

It would be great if there was some more data on the motors apart from the basic info on the AC WORLD site as I really dont want to kill my little 30/24 testing its limits.

Would we expect comprehensive motor data on your new website? That would be great.

I've got a sneaking suspision that the F16 and Su27 in the videos are using the Ultrafly motors?? I know what mine "sounds" like on direct drive!

Here a link to some direct drive ultrafly 30/24 action on 2s2p and a 6x5.5 apc e.
Starjet on Ultrafly 30/24

Ill buy that F16 or Su27 as soon as you tell me when/where I can get one.

Keep up the good work charlie!
May 05, 2004, 04:33 AM
veni,vidi, roto volubilis
Happy|Harry's Avatar
great article!, and it's good to finaly see pics and videos of your planes charlie, i look forward to trying some of the planes out

May 05, 2004, 10:38 AM
Registered User
fleanme's Avatar
those are great looking planes.
does that cessna have flaps?
and what are your scheduled plans for release of these plane?


edit: are those jets EDF's?
Last edited by fleanme; May 05, 2004 at 11:26 AM.
May 05, 2004, 09:28 PM
RC Player
Hi Neal,

All these are in production. We estimate it would come to market by early July!
Hawk is a back pushed aircraft. let me copy a paragraph from our airplane introduction:

“Fly just like a JET!” is what we are delivering!
The T-45/Hawk is able to fly just like what you can expect from a jet airplane. Its stock power system gives it enough strength to do a 70 feet high loop continuously. The roll rate is about 4-6 roll/sec. However, in its landing approach, the unique wing design enables the aircraft to lower down its speed to 10 miles without tip stall. The special 15-degree down angle of the elevator provides the stable control in its high-speed maneuver and low speed approach.
This T-45 (Bae Hawk) uses a Firestone Gearbox with Ultrafly 400 motor. This power system (shown in the picture) is designed to be strong and capable of delivering 180 watt of power. The power system is configured with 1.89 to 1 gear ratio and turning an APC 6x5.5E propeller at 12000RPM. The 12V battery is discharging 9A and output 96 watt which enables this aircraft to fly as you expected. The scales like canopy is formed by upper and lower part of vacuum mold and attached to the fuselage with magnet for convenient access to the battery.

May 05, 2004, 10:48 PM
Registered User
fleanme's Avatar

thanks charlie

the f16 flew like it was an edf. is it?

how about that cessna. that photo looks like maybe there are flaps?

edit: took a closer look at the photos. i saw the flaps on the cessna. very nice.
Last edited by fleanme; May 05, 2004 at 10:51 PM.
May 06, 2004, 12:03 AM
RC Player
Hi Fleanme,

Cessna does has flap and fly like a real one! It also come with steerable front gear/rudder. The 1.1m wing span and wing area is big enough to carry another 200g of load but you need to upgrade the power system for that purpose.

F-16 you saw is the No. 6 prototype. It flys terriblly! Until prototype 10, we fixed all the problem. This model took us more than 6 months of time to developed it and also the most expensive in R&D process. We need another 3 month to put it into production. I will come around September time frame.

May 07, 2004, 02:50 PM
Registered User
Patrick Plawner's Avatar
Utrafly model A30/29, installed in Protech Tigermoth. With 8 cells and 8x4 prop.

See the video, the motor works fine
May 07, 2004, 03:45 PM
Registered User
Peter Khor's Avatar
Wondering if GP will only be bringing in the planes, or will the brushless motors be available via GP also?
May 08, 2004, 05:17 AM
RC Player
Great Plan do distribute this motor! It will be available in 2 months. If you can't wait, AC is still the fastest way!

May 08, 2004, 05:33 AM
RC Player
Inside info:

Su-27 & F-16 use Falcon 400 motor(a special winding 400 motor) with 1.9 to 1 gearbox running an APC 6x5.5 at 12000rpm if you use 10cell Kan1050. You may use Hecell as well but the rpm will goes 400rpm lower. Flying are almost the same. It really don't need a brushless to rock & roll.

Su-27 should be available in 3-4 month from now. F-16 late this year!

The only airplane uses brushless motor is the Ultimate 3D. This would be available with Su-27.


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