HobbyKing Avios Extra 330LX V2

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Written by Jon Barnes
Second Generation Has Improved 3D Performance
As seen in the September 2021 issue of Model Aviation.

Bonus Video

HOBBYKING KICKED OFF ITS 2018 calendar year with the release of an Avios-branded, EPO foam-composition Extra 330LX. That 3D/aerobatic model spanned 1,420mm and came equipped with a four-cell-powered, brushless electric power system. Adorned in a Mirco Pecoraricommissioned blue, orange, and white graphics scheme, the model cloned a full-scale Extra 330 that was then being flown by the original founder of the RCGroups.com forum-based website.

As is often the case in the industry, worldwide inventory of this model dried up within a year or two and the model, along with a selection of relevant and often much-needed spare parts, was no longer available. Although Hollywood wins hands down when it comes to being the king of sequels, it is not entirely uncommon to see many foam models return in a refreshed form. HobbyKing has done exactly that in 2021 with the release of a second-generation, EPO foam-composition, 1,420mm Avios Extra 330LX.

One immediately visually obvious difference right out of the box is that the Avios Extra now sports a neutral (unsponsored and unaffiliated) and seriously snappy-looking red, white, and black graphics scheme. The specifications of most of the electronics used in this Plug and Fly kit align quite closely with those used in the original version.

Four 25-gram, high-torque, metal-gear digital servos are used to authoritatively deflect the control surfaces. Although the ad-speak for V2 touts a more powerful stock power system, the brushless outrunner motor used in this V2 kit is listed as a 4248-600 Kv motor (V1 reportedly used either a 4240-600 Kv or 4250-600 Kv brushless out-runner motor). Although one of the official HobbyKing V2 Extra videos mentions that the motor has been upsized to a 650 Kv outrunner motor, the review model came equipped with a 600 Kv motor.

Both V1 and V2 kits specify a 60-amp ESC and 14 × 7 wood propeller. A pull-pull cable system is retained on V2 for rudder control, with minimal-slop, ball link-equipped pushrods covering the elevator and aileron servo connections.

One interesting (and endorsable) omission in round two of this Extra is the wing root-mounted multipin connectors that are typically employed on models to simplify connecting the wing-mounted electronics when removing/installing the wing halves.

Models utilizing multipin connectors often feature electronically complex wings. Signals passed through this type of connector typically include ailerons, flaps, landing gear retracts, and lighting connections, all of which need to be routed into the fuselage for the ultimate connection to the receiver and/or a DC power source.

With only a single 25-gram servo mounted in each wing half, using multipin connectors on this model is undeniably superfluous. The more traditional, oldschool approach of servo extensions routed through holes that are molded into the wing roots helps keep this 3D/aerobatic model—a fixed gear tail-dragger airplane with no flaps or LED lights—uncomplicated.

Another purely aesthetic deviation in round two is the elimination of a pilot figure and clear canopy. This V2 Extra goes with a gray-painted canopy. Although some might rue the loss of an included pilot figure, the cartoonish figure normally utilized looks that were anything but realistic.

Covering the cockpit foam with a solid canopy also protects the foam, preventing it from wrinkling over time because of excessive exposure to sunlight and UV rays.


A paper assembly manual is not included in the box. A full-color, 14-page digital version is downloadable from the Extra 330LX V2’s product page on the HobbyKing website (click on the Manual/Files tab). Although it is somewhat sparse in the amount of information and guidance that it offers, with simple line-art style graphics calling out the size and length of the various fasteners used to assemble the airframe, most pilots should have no problem figuring out how to assemble this kit.

HobbyKing commendably segregates the relevant hardware used to assemble each airframe component into small, labeled plastic bags. Manufacturers often include extra fasteners with their kits. Some of our bags did contain extra hardware, but I was dismayed to find that several of them were missing the required number of fasteners to get the job done.

As an example, each side-force generator (SFG) attaches to the wingtip with two small screws. My bag held a total of three. Most pilots can easily rummage around in their spare parts bins for any needed fasteners, so this fastener shortage was an inconsequential and relatively minor glitch in assembling the Extra.

this prepainted epo foam composition kit assembles quickly
This prepainted, EPO foam-composition kit assembles quickly, without any need for adhesives. The embedded toolless, plastic, wing-retention clips allow the wing halves to be removed for storage and transport in a matter of seconds.
accessed from the top the battery bay features abundant space for the recommended
Accessed from the top, the battery bay features abundant space for the recommended 4S or 5S battery packs. The length of the battery tray allows pilots to position their packs fore and aft to achieve the optimal center of gravity.

HobbyKing uses large, lovely, and appropriately lengthy composite-construction control horns on this model. Given this 3D/aerobatic model’s pedigree, and when combined with the uber amount of torque generated by the included digital metal-gear 25-gram servos, it appears to be a recipe for post-stall and precision aerobatic maneuver success.

While installing the ball link-equipped elevator pushrod, I was surprised to find that it was too short to bridge the gap between the servo control horn and elevator control horn. I solved the shortage by sourcing and falling back to a more traditional metal clevis, one with alternate dimensions that offered enough additional length to make the connection.

Another possible solution would be to remove the elevator servo from the fuselage, rotate it 180°, and reinstall it, with the net effect of such action being to bias the offset location of the servo spline toward the rear of the fuselage instead of the front.

A final noted faux pas from the factory involves the empennage assembly’s plastic fore-post. When mating the tail assembly with the fuselage, pilots should note that although the plastic alignment pin of the tail assembly is square, the foam receiver into which it mates in the fuselage is round.

A pilot could choose to force it into place, but I thought it to be a more judicious approach to carefully remove the necessary amount of foam to re-form the round hole in the fuselage into a shape more willing to receive the mating assembly.

Because this version of the Extra eschews the use of multipin connectors on the wing roots, pilots might find it advantageous to use small pieces of hook-and-loop material to secure the aileron extensions in place and prevent them from falling back into the fuselage when removing the wing halves for transport and storage.

With a small piece of loop material placed on the aileron extension servo connector and a slightly larger piece of hook material placed on one of the surfaces of the square-shaped cutouts in the wing roots, pilots can conveniently secure the aileron extensions in place for easy retrieval the next time they assemble the airframe!

Another nice feature sure to make assembly/disassembly quick and painless is the model’s use of embedded snap-lock wing retainers. No tools are required when attaching or removing the wing halves—just insert the spar through the fuselage, slide both wing halves onto it, and carefully seat them in place until secured by the plastic retention locks.

an oversize composite construction control horn and pull pull rudder cable system
An oversize, composite-construction control horn and pull-pull rudder cable system combine to create maximum rudder throws with minimal backlash.
pilots might want to crimp the ends of the springs closed after attaching
Pilots might want to crimp the ends of the springs closed after attaching them to the aluminum rudder tiller bar. The review model’s springs were prone to pop free until the loops were pinched closed.


Pilots who are interested in hot-rodding their 330LX by going to a 5S battery might find the following data valuable. I ran the Extra across a wattmeter in the pits before the first flights. Short, static throttle run-ups using a freshly charged battery pack showed that the included stock 14 × 7 propeller pulled roughly 45 amps, with total watts coming in at approximately 675 when held at a wide-open throttle for 10 to 15 seconds.

This computes to an approximate power-to-weight ratio of slightly less than 140 watts per pound (when using a 4S 3,000 mAh Nano-Tech battery pack). Pilots who prefer a little more get-up-and-go in their vertical punchout runs usually prefer that number to be closer to 175 to 200 watts per pound. With a switch to a 5S pack, I saw these two data fields climb to 58 amps and slightly above 1,000 watts, respectively.

Although this data hints that pilots who are interested in exploring a higher-performance model might be able to stick with the stock 60-amp ESC, especially in light of the empirical knowledge that a propeller will always unload a little in flight when compared with running it on the bench, the manufacturer’s recommendation to upsize the ESC to one rated for 70 to 80 amps when switching to 5S packs will admittedly come with the advantage of creating a little headroom.

Pilots who plan to aggressively push this airframe will likely appreciate the peace of mind offered by this approach, but those who are interested in flying the model on a 5S pack using the stock power system could get away with it if their flying style limits the time spent at a wide-open throttle.

this second iteration of the avios extra loses
This second iteration of the Avios Extra loses the RCGroups.com blue, orange, and white color scheme that was used on the first version and replaces it with a more conservative, attractive, red, black, and white color scheme. Removable SFGs contribute to this model exhibiting nearly zero coupling when flown in knife-edge flight.

Ambient temperature will also factor in, with colder environments less likely to create a scenario that could strain the stock ESC on five cells. Another explorable option would be to stick with the 4S pack and perhaps switch the propeller to a 15 × 7, although pilots will want to check the load of an alternate propeller using a wattmeter before sending the model aloft.

There is an abundance of power on tap beneath the cowling to keep this Extra tracking on the rails through nearly every imaginable precision aerobatic maneuver. Josh and I were pleasantly surprised to find that entering a short upline with the proper amount of aggression would allow the Extra’s superior yaw authority to execute a wild, three- or four-rotation pop-top.

As promised in the marketing materials, knife-edge flight exhibited almost no coupling whatsoever. Few foam aerobatic models can claim zero coupling with a straight face. We were pleasantly surprised to find that claim was as close to the truth as it was. And the less coupling that is present, the less time that is required to mix it out, creating more time to enjoy the model and its overall, well-behaved flight characteristics.

Shifting the airframe into the post-stall realm also proved to be a delight. This foam Extra performs harriers, both upright and inverted, with confidence-inspiring stability (we did use a gyro in ours). Using the stock 4S power system, this model will nicely hang on the propeller in a hover, although pilots will want to make sure that they remember and respect the nearly complete absence of ample reserve power with which to arrest a tail slide or to punch out of a hover vertically with gusto.

Pilots who are interested in practicing a hover should do so early in the flight when the flight pack is strongest. Stay several mistakes high and perhaps avoid using older or lower C-rated battery packs that might not provide the necessary thrust to arrest the airplane’s descent if negative inertia builds during the maneuver.

On many airplanes, rolling harriers are performed with full aileron deflection. The roll rate on this Extra was aggressive enough to require a slight reduction of net throw (roughly 80% to 85%) to keep the rolling harriers from accelerating into rifle rolls. One small adjustment that we made after a few flights was to crimp the ends of the springs used on the tail wheel assembly. Ours popped from the aluminum rudder tiller bar several times.


At the time that I pulled this review together, this model was discounted in the US warehouse by $20. Spare parts that are available for purchase include the wing halves, SFGs, stabilizer, fuselage, landing gear, spinner, propeller, and the carbon-fiber wing spar. Maintaining a proper supply of spare parts in inventory for longer than what has become typical in the industry is sure to help this model gain the popularity it deserves.

Veteran 3D/aerobatics pilots who prefer a little more punchout performance might wonder why Avios did not just upsize the ESC that is included with this V2 kit to the optional 70- to 80-amp setup. Beginnerand intermediate-level 3D/aerobatics pilots who might not be quite as focused on equipping their airplanes with no-holds-barred, extreme power-system performance will definitely find this model to be a perfect candidate for developing and improving their 3D and precision aerobatics chops!

the stock 4s power system makes enough watts to hang this big extra on its propeller
The stock 4S power system makes enough watts to hang this big Extra on its propeller, although pilots should respect the relatively limited amount of reserve power on tap when it is time to punch out or arrest a tail slide.
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