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Written by Andrew Griffith
A high-quality electric helicopter kit.
Read the complete review in the July 2014 issue of
Model Aviation.



Specifications

Model Type: Electric Helicopter
Skill level: Intermediate to Advanced
Main Rotor Diameter: 49.6 inches (1,260mm)
Length: 44 inches (1,120mm)
Height: 13.8 inches (350mm)
Main Rotor Blades: 550mm
Tail Rotor Blades: 92mm
Weight: 8 pounds, 1 ounce
Drive System: Belt drive with torque-tube tail drive
Gear Ratio: 8.46:1; 3.86:1 (tail gear)
Power system: 6S LiPo
Radio: Six-channel minimum
Construction: Carbon-fiber stacked frame
Motor Kv: 1,100
Street Price: $1,159 (combo); $649 (kit)


Test-Model Details

Motor/Engine: KDS BL4020 1,100 Kv (included in combo)
Battery or Fuel: OPTIPOWER Ultra 6S 22-volt 5,000 mAh 50C LiPo
Radio system: Futaba 8FG Super 14-channel radio; Futaba R6202SB FASST Dual S.Bus HV receiver; three KDS N630HV cyclic servos (included with combo); one KDS N650HV tail-rotor servo (included with combo)
Ready-to-fly weight: 8 pounds, 1 ounce
Flight duration: 4-6 minutes, depending on head speed


Pluses

• Carbon-fiber frames and tail boom for a strong and lightweight frame.
• Belt drive is smooth and quiet.
• Torque-tube-driven tail with large spiral cut for smooth tail control with minimum power loss.


Minuses

• No printed manual provided with kit.


Excepts from the Review

What a wonderful time to be involved in RC helicopters, or model aircraft in general! I’m dating myself, but when I first started flying helicopters, hovering twice in the same day and taking a helicopter home in one piece was a major accomplishment. The two or three people in the country that could hover nose-in were guaranteed a spot on the podium at the AMA Nats. Today we have lightweight models and radio systems with components that we could only dream about 10 years ago.

The good news is that we have a lot of choices available to us in every size, shape, and power system, and it seems like new models are entering the market almost daily. The bad news is that we have so many choices available that sometimes narrowing down the list to a final purchase is little bit overwhelming. Thankfully most of the hobby-grade helicopters are of very high quality, so it’s difficult to make a bad choice; you simply need to find the one that meets your needs and desires.

The Agile 5.5 is the first 550-size helicopter that I have owned. My club field is home to a number of active helicopter pilots, including a couple of members of various teams. Between helping others and watching what the team guys are flying, I’ve been exposed to a large variety of helicopters. The 550-size has piqued my interest lately, as it has the power and presence in the air of the larger models with a more modest cost, especially in the battery department.

Since attending the Orlando Helicopter Blowout, I have really been getting the itch to fly helicopters more. I have been doing a lot of airplane reviews lately and consequently, my helicopter skills are slipping due to lack of practice. I wanted something that was small enough to carry in the truck with my other projects, and electric-powered so that I could get a few flights in each flying session without hauling around all of the support equipment required to fly nitro.

I was attending the Blowout when I ran into Allen Bryan from KDS Models USA. The company had a tent with a number of helicopters on display, including the Agile 7.2 and its new little brother, the Agile 5.5. Allen is the CEO of KDS Models USA, which is located in a large distribution warehouse in Houston, Texas. After watching factory pilot JaeHong Lee really give it to a 5.5 during a noon demo, I sat down in the KDS tent for some time with Allen to discuss the new Agile 5.5, see what it brought to a fairly crowded market, and finally handshake on an agreement to receive one of the new kits for review.

I was curious what made the Agile different from the growing number of helicopters in the 550 class of electric helicopters. Roberto Gaziano designs robotics for media and military applications and turned his considerable talent to the task of designing the Agile series of helicopters. Two years of development and testing went into bringing the Agile 5.5 to the market and included both Roberto’s engineering talent and factory pilot JaeHong Lee’s extensive flight testing of the prototypes.

Some of the unique features are the two-stage belt-drive system and the high-quality components that result in a very rigid airframe. KDS has been a major supplier of CNC components, tools, and electronics for the RC industry for some time, and manufactures nearly all the components for the Agile up to and including the screws, so there is control of the quality of the parts from beginning to end.

My first impression when unpacking and examining the Agile was that everything was well organized; not only was it organized, but it was very well organized. The larger parts are nicely arranged in molded trays with a spot for each part. Unlike other kits, the Agile screws and small hardware are bagged by size and type. All of the socket head M3 x 10 screws are in one bag; when you need four of them for a step, you remove them and seal the bag. It’s different than some kits, but I like the way it was done, as the end result was that everything needed could be found quickly.

Building the Agile 5.5 isn’t difficult, but you should take your time and build it carefully and precisely. I used Z-42 threadlocker and Pacer Z-Poxy from Frank Tiano Enterprises to assemble the Agile. It always takes more time to document a review build, but I estimate that it would take approximately 5-7 hours to build and set up another Agile.

The first thing that really surprised me with the Agile was how stable it was even in the prevailing winds. In Idle Up 1, the Agile felt extremely solid without being twitchy. The solid feel gave me confidence to fly around a little bit and get used to the Agile. I didn’t try much in the way of aerobatics, but two things really stood out that day. The Agile was very stable even in the wind and it was fairly fast, especially moving downwind. I’ve found that higher airspeeds tend to reveal any bobble or instability in the rotor-head design or the flybarless control unit. The Agile exhibited no bad tendencies and the EBAR maintained a good balance of quickness and stability. As a result I was quickly gaining confidence in both myself and the model.

I noticed as I started doing funnels and hurricanes that the tail was shuddering a little. Here’s where the EBAR controller is great. Just land, tweak the gain, and get back in the air to test. I had the entire helicopter tuned to my liking in two packs. Every time I landed the Agile it seemed to ask, “Is that all you’ve got?”

Read the full review in the July 2014 issue of Model Aviation.



The author displays his new Agile 5.5. The Agile is compact and will easily fit in any vehicle.





Conclusion

Agile: An adjective meaning quick and well-coordinated in movement; lithe; active; lively.

I would say the KDS Agile 5.5 definitely meets and exceeds the definition!

I found the Agile 5.5 to be both responsive and solid. The Combo Kit was comprised of components with performance and satisfaction in mind; a welcome departure from combo deals that are put together with the sole objective of saving money by using marginal components. The components are high quality and have withstood my more-sedate flying style, as equally as holding up to “let’s see if we can break the Agile in flight” without missing a beat.

While not an inexpensive kit, the Agile is well engineered and appears to be assembled using high-quality components for an uncompromising final product.

—Andrew Griffith
andy@customcutgraphix.com


Flight Video



Manufacturer/Distributor

KDS Models
allen@kdsmodelsusa.com
www.kdsmodelsusa.com


Sources

Castle Creations
(913) 390-6939
www.castlecreations.com

Futaba
(217) 398-8970
www.futaba-rc.com

ExperienceRC (OPTIPOWER)
(989) 488-7813
www.experiencerc.com

Frank Tiano Enterprises
www.franktiano.com

Super Glue Corporation (Pacer Technology/Zap Glue)
(800) 538-3091
www.supergluecorp.com/zap-brand-products

DuPont (Teflon Silicon Lubricant)
(631) 666-4186
www.dupont.com/

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