Hobbyking Avios Grand Tundra - FlyingGiants Review
The Grand Tundra is a high-wing taildragger centered around two massive tundra tires and a pair of shock absorbing landing gear. It's an rc bush pilot's dream and has successfully re-ignited the aviation spark in my life.
A Grand Bush Plane
| Product: | Avios Grand Tundra |
| Retail price: | $349.87 |
| Wingspan: | 67" (1700mm) |
| Length: | 49.6" (1260mm) |
| Material: | EPO foam |
| LED Lights: | Switchable landing lights, always on nav lights |
| Motor: | Turnigy Aerodrive SK3 5045 500kV |
| ESC: | 60a Aerostar w/ Reverse |
| Included Propellers: | 17x8, 16x8 |
| Recommended battery: | 4s - 6s 4000mAh |
| Battery used: | 4s 5000mAh |
| Recommended radio channels: | 7 channels |
| Available from: | Hobbyking |
The bush plane is a popular aircraft in the rc world, as it's the natural progression for a modeler is to add giant tundra tires to at least one airplane in their hangar, and then attempt to fly it off of the most inhospitable surfaces. The new Grand Tundra from Avios takes the guesswork out of sourcing sprung gear and truly soft tundra tires by pairing them with a STOL airframe, a giant propeller, and installed electronics. The resulting combo is a rugged high-wing that, in my case has inspired me to get back out and fly, even with the local temperatures barely above freezing.
In this review, I'll assemble the Grand Tundra and fly it at a relatively rough field with pilot CJ Kurella on the sticks. Let's get started.
What's in the Box - Fit and Finish
The Grand Tundra shipped to my door safely in a stout cardboard box and foam cradle, which is standard procedure for ARF foam aircraft these days. All parts were wrapped to prevent contact damage, and the only broken parts were a few of the vortex generators that were missing fins. Luckily, extras were included and I only had to use one broken one on the aircraft.
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The EPO airframe of the Avios Grand Tundra. It's available in green/gold, and blue/silver.
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The Grand Tundra features plug-in wing connections to make assembling in the field a painless affair.
The airframe has a high level of completion from the factory. Servos are installed with the horns in the correct location, and all electronics were mounted and ready for service. The graphics were applied well with no issues worth noting.
One area that caught my attention was the plug-in connectors on the wing root. These types of connectors have been given a bad reputation in the past, and personally I think that reputation is completely unfounded. Some critics consider them a failure point, but I have never experienced an issue. The Grand Tundra's wing plugs slide together smoothly and show no signs of ever failing. Time will tell, but I'm confident in this design.
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The bottom of the fuselage has plastic mounts for the landing gear and optional floats. Note the standard air exit holes in the rear of the fuselage, which direct cooling air out efficiently.
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The included Aerostar 60A ESC. It's reversible for precise taxiing on the water with the optional floats.
On this list of included electronics is a Turnigy Aerodrive SK3 5045 500kV motor, an Aerostar 60a ESC that's reversible for precise maneuvering on the optional floats, an LED lighting system with on/blink/off control for the landing lights, and an LED blinking beacon on the belly. Mini metal-geared servos are used for the control surfaces, and micro 9g servos are utilized for the flaps.
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A look at the included Turnigy Aerodrive SK3 5045 500kV motor. It can swing a large 17x8 for 4S or 16x8 for 6S battery configurations.
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The wings are setup with flaps capable of 90-degree deflection. All servos are pre-installed and the only requirement is installing the pushrods.
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Huge balloon tires with black painted wheels are standard on the Grand Tundra. They are spongy foam and quite functional at absorbing a hard landing, especially when coupled with the sprung main landing gear.
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A pair of props are included: 17x8 for 4s and 16x8 for 6s power setups.
The landing gear and tundra tires are a work of art on the Grand Tundra. The main gear are made of steel and are quite functional with the included rubber bands absorbing the energy from even the hardest landings. Coupled with the very soft foam rubber tires, the Grand Tundra can taxi, takeoff, and land on very rough terrain.
Assembly
The photos below with captions detail the main assembly steps. As I say in every review, follow your assembly manual for detailed instructions. The Grand Tundra goes together very quickly, and even includes a Philips head screwdriver and hex head wrench for bolting on the main landing gear, the tail gear, and the elevator halves. The rudder snaps in without any fasteners.
The use of CA adhesive is required only for the vortex generators; place a small drop of foam-safe CA on the slit in the foam and press each vortex generator into place.
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With the main gear installed, wrap two rubber bands on each leg. You can make the spring resistance harder or softer with the number of wraps you make with the rubber bands.
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The Grand Tundra is sitting on it's landing gear and ready for final assembly.
The shock-absorbing landing gear are a functional thing of beauty, and arguably the focal point of the aircraft... oh and those big tundra tires!
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The horizontal stabilizer and elevators are installed, and pushrods connected.
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Here we see the rudder installed in the vertical stab and pushrod in place.
I was happy to discover that all servo horns were installed from the factory at their correct positions, and only minor adjustments to the control rod lengths were in order.
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The sprung landing gear a quite soft with minimal wraps of the rubber bands. You can add more wraps to increase stiffness to your liking.
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The vortex generators will definitely keep clean air flowing back to the ailerons; a characteristic that's great for slow speed maneuverability.
Transmitter Setup and CG
With my brand new Futaba 16SZ being used for control, I setup the Grand Tundra with the flap-to-elevator mixing, a necessary mix to prevent ballooning when the large flaps are deployed at high angles. A few degrees of down elevator with the flaps corrects any nose-up tendencies. Depending on the size of battery you use and your CG location, you may need to fine tune the amount of elevator you mix with the flaps. Next, I put the landing lights on a switch and plugged them into my receiver. The pair of landing lights on the wings gets 5v power from the receiver, and with a 3-position switch, can be cycled off, on, and flashing.
Aileron travel (end point adjustment) was set at 60%, elevator was set at 70% down and 110% up, and rudder was set at 100%. Expo was set at 45% for all control surfaces, making the Grand Tundra perform scale maneuvers nicely around center stick, but still allowing a nice roll rate when the ailerons were pushed hard.
The Avios Grand Tundra calls for a 4s to 6s 4000mAh LiPo, and I opted for what I had on hand: a 4s 5000mAh. She balanced easily with this 14.8v pack at the recommended 60mm back from the leading edge.
Videos:
| Hobbyking Avios Grand Tundra - RCGroups Review Part 1 (5 min 54 sec) |
| Hobbyking Avios Grand Tundra Flight Demo - RCGroups Review Part 2 (4 min 36 sec) |
Flight Report
As the name suggests, the Grand Tundra is a large airplane when compared to its little brother, the Durafly Tundra. But even with a 4s 5000mAh LiPo feeding power to the 500kv motor, the Grand Tundra feels light and nimble on the sticks. We flew the GT at a relatively rough field to test out the functional landing gear and soft foam tundra tires. I had my friend and test pilot CJ Kurella on the sticks as I shot photos and video.
From takeoff to landing, and every second of flight in between, the Grand Tundra flew on a rail and exhibited no bad tendencies.
With flaps down or up, the Grand Tundra gets on the wing and takes off quickly and easily. Rolling takeoffs are in the 15 foot range without flaps; cut that in half with the flaps at 45-degrees.
The big 17x8" prop pulls the GT around with authority, and acts as a massive air brake when at idle; you can hear it cutting through the clean air very noticeably.
General sport aerobatics weren't a problem for this oversized bush plane, although knife-edge flight required more rudder input than we had setup. Loops, rolls, and hammerheads were uneventful and quite entertaining... this isn't a sport aerobatic airframe but performed the maneuvers well.
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Look at that gear! We purposely flared the Grand Tundra a few feet off the ground to test the gear and tires. They didn't disappoint.
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The GT looks right at home on this rough field.
As I said earlier, the oversized tires and sprung landing gear are the focal point of the Grand Tundra, and watching them do their job of soaking up the rough stuff was quite satisfying to watch. We flew a number of landings where we purposefully flared a foot or two off the ground, only to have the gear and tires soak up the impact without any issues.
The 4s 5000mAh LiPo provided flight times in the 8-10 minute range with 30% left over. That included a mix of sport aerobatics and flaps-down cruising. You could stretch 12 minutes out of it with some throttle management.
Conclusion
The Avios Grand Tundra has rekindled my love of flying model airplanes. Over the years, you begin to expect more out of airframes, and the desire for something new and unique becomes a daily reality. The Grand Tundra delivers on that with its off-road style landing gear and tires that just beg for take offs and landing in places other models wouldn't even consider rolling. The GT flies with authority at fast and slow speeds, making it an easy transition from a beginner high-wing airplane. Finally, it's a very complete ARF, meaning all electronics are installed and minimal assembly is required to get the Grand Tundra on the wing.
So if you're in the market for an airplane that will impress you and your flying companions, not only for its utilitarian looks but also for it's rugged and solid performance, then look closely at the new Avios Grand Tundra, as it will not disappoint.
Last edited by Matt Gunn; 04-02-2018 at 10:44 AM..| Thread Tools |
04-02-2018, 11:23 AM
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United States, PA, Delmont
Joined Mar 2013
25 Posts
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Using unsightly rubber bands for shock-absorbing on the LG was really idiotic when a simple change of the connecting lugs so that steel springs could be used would have been much better both functionally & aesthetically. The cost would have been negligible.
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04-02-2018, 11:40 AM
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United States, FL, Jacksonville
Joined Dec 2007
9,372 Posts
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Nice job Matt!
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04-02-2018, 12:54 PM
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United States, TX, Sealy
Joined Mar 2008
534 Posts
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What a great looking airplane, and looks like fun to fly also !
GM |
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04-02-2018, 07:28 PM
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OHIO
Joined Nov 2017
31 Posts
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Terrible.
"Paid review." |
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04-03-2018, 07:03 AM
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Muncy,pa
Joined Oct 2006
115 Posts
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Quote:
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04-03-2018, 10:25 PM
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United States, FL, Center Hill
Joined Jul 2014
1,520 Posts
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Anyone know what the full scale is called? I have had a full scale fly across my property the last three evening that look identical to this plane but it is red. I'll keep the camera on the patio for a few evenings and if it comes again take a photo.
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04-03-2018, 10:35 PM
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United States, OH, Parma
Joined Oct 2009
1,566 Posts
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Quote:
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04-09-2018, 05:45 PM
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NorCal, East Bay
Joined Feb 2009
420 Posts
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The Avios is not based directly on a full-scale plane, but shares many common features.
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Also looks similar to a Kitfox: |
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04-14-2018, 07:18 AM
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United States, GA, Cumming
Joined Jan 2008
55 Posts
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Like the plane...and looking for something different... so have one on the way...
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