E-flite Radian XL 2.6m BNF - RCGroups Review - RC Groups

E-flite Radian XL 2.6m BNF - RCGroups Review

The Radian's big brother is here and RCGroups took it to the field to see how this big bird flies.

Splash

The New Radian XL has a 102.4 Inch Wing Span!

Wingspan: 102.40 in (2.6m)
Wing Area: 946.45 sq in (61.05 sq dm)
Length: 56.9 in (1444mm)
Flying Weight: 79.5 oz (2254g)
CG (Center of Gravity): 91mm behind the leading edge @ the root
Motor: BL 10 1250Kv
ESC: 40A
Prop Size: 12x4
Battery: 3S 3200mAH Lipo
Available From: E-flite
Price: $229.99

When I was on the ground at Joe Nall it was hard to miss the newly debuted Radian XL. It's big, we're talking surf-board big! It seemed to have lots of power and a magical ability to find lift. I guess that certain look an rc pilot gets when he sees a plane he wants must have been beaming out of my eyes because I was the lucky one to get to review this big sailplane!

I got my introduction to sailplanes from Jim Martin, the founder of Hobby Lobby. If he was at our field, he was flying a sailplane. The next person to push me into sailplanes was Skip Miller; I've had three DLG sailplanes over the past few years. The trick was getting it high enough to find a thermal. Thermals get wider the higher up you go. The Radian XL was my first powered glider in many years. I was excited to get it in the air and see if we could find some lift.

Radian XL Flight Review - RCGroups (9 min 16 sec)

Features

  • Big - easy to see and easy to fly
  • Efficient 2.6-meter polyhedral wing with fully-proportional spoilers
  • Full-Flying horizontal stabilizer for superb pitch control
  • Assembles and disassembles quickly
  • Powerful, efficient brushless motor
  • Constructed of durable, lightweight Z-Foam material

Needed To Complete

  • 5+ channel Spektrum DSMX/DSM2 transmitter
  • 3S 3200mAh LiPo battery

What's In The Box

For such a big plane, there was very little to do to get it flying. The hardest part is finding a work area large enough to get the plane together! Everything in the fuselage was pre-built and ready to go. Servos, the AS3X receiver, motor, and prop were all installed out of the box. I did have to CA the rudder on, but that was almost too easy to really mention. I didn't time myself, but I think I had it all together in around 20 minutes.

AS3X Receiver

The BNF version not only had the receiver installed and ready to go, but it was pre-programmed to work with my DX-9. That meant I didn't have to trim anything or setup the spoilers, all I had to do was bind the plane; the bind cable was pre-installed in the fuse. I connected the bind cable and fired up my DX9 and all was right with the world. I actually spent some time searching the web and writing Horizon about the TX setup before I realized it was already done for me. The spoilers were even setup on a three-way switch. If you are wondering how the trim was, I'll touch on that in my flight section.

Spoilers and Wing

First of all, spoilers are always pretty trick to have on a model, but on a big sailplane like this they are essential. The fully-proportional, retractable spoilers really help you manage your descent and use less area to land.

The 102 inch wing, was designed for thermal-grabbing with minimum drag. It's just so dang big that it really signals lift and is a great aid in catching thermals. But, it's big enough that you'll be breaking it down when you put it in your car, or even your truck.

Full-Flying Horizontal Stabilizer

The Radian XL has a full-flying horizontal stabilator for good pitch control. The entire surface rotates up or down to provide extra aerodynamic force. This give great elevator response at any speed. Plus, it's high enough off the ground not to catch grass.

The Fuse

That's a long fuselage and the question I was getting at the field was, "Is there carbon fiber in that fuse?" The word from the designers is. "Mid wing aft to about mid section of the vertical fin. Yes there is." I can say after flying her I never saw any issues, wiggles, or weakness.

Brushless Power

The power system on this plane was stronger than expected. It flies right out of your hand and can get you down from any large thermal with plenty of power to bring it home to your feet. Not having a motor on my DLG birds really made me appreciate the instant-on capabilities of this power plant. With a flick of the throttle I was back up and looking for new thermals.

Breakdown

When you get the box you will immediately realize how big this plane really is. I had dreams of keeping the wing in one piece and loading the fuse and wing side by side in my truck. I drive a huge Ford Excursion and the wing would poke into the drivers area.

Taking the wing tips off is super simple. I hate having to keep up with screws (especially when loosing them means no flying). After I remove the wing tips I put the screw back into the tabs for safe keeping. I also have a bag for the wing hold-down screws that rides with the plane.

I took the shipping box and cut it in the appropriate places to hold the fuselage and the broken-down wing. This is a great way to keep everything in one piece, and I keep my screws and a screw driver in the box.

Flying

This is the best part of the review. I was at my yearly event I have in Nashville; we fly in a 100-acre field. RCGroups user (and old friend) Wind Junkie was there and I grabbed him to fly with me. He has experience with the Radian, so before we threw the XL into the air I asked him what he expected.

He thought that since it was a foam plane the penetration would not be that great. He as also wary of the power system. He didn't think there would be enough power on tap to get out of trouble.

I figured we would have to trim the rudder and elevator before the flight but it seemed to visually look perfect right out of the box. We launched it with little effort. Our close-up video had to be postponed because the plane flew directly into a thermal and started going up. It went so high we had to shut the video camera off! What are the chances of a first launch into and screaming thermal?!

The Radian XL had the power needed to break out of that thermal and come home. The spoilers worked just as they were supposed to, they simply slowed down the plane and caused it to drop by killing the lift.

We did some low speed, low altitude camera-shot cruising while I took photos, then it was back up into the sky. I realized at this point we had yet to touch the trim tabs after launching. Incredibly, the Radian XL was trimmed perfectly without touching anything!

At the top of the review is my flight video. You can see the first launch into the thermal and hear Wind Junkie and I discussing the plane and its flight characteristics.

Build Photos

Flying Photos

Conclusion

I love this bird. Out of the box it builds super fast, and it looks great. The AS3X was ready to go right out of the box and it was barely noticeable in the air. I have to think that it's tuned to the point that it just does it's job and we simply fly the plane. The XL really allows you to read thermals due to it's large size, which is evident in my flight video; it's a big baby to fly. You have lots of time to thing about what you are going to do next. I'm used to looking at tiny planes in the sky every second so I don't get turned around. The Radian XL is so "XL" that you won't have to worry about that.

Generally, big planes like this are a pain to get loaded, unloaded, and put together and get into the air. This is a big bird, but getting everything screwed on could not be easier - I think that's a big plus!

The fuselage and battery tray are easy to get to, and plugging in the spoilers is a no-brainer. Thanks to the power system launching is also super simple.

This is a well thought out sailplane that I think anyone would enjoy. Horizon has done it again!

Last edited by Matt Gunn; Oct 04, 2016 at 10:09 AM..
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Oct 10, 2016, 11:47 AM
Sagitta Fanboy
Nice review, but that was for the BnF Basic, not the new PnP version which does NOT include a receiver.
Oct 10, 2016, 02:12 PM
rcnova
summary: Very Heavy combined with a lethargic power system
Many reinforcements are heavy fiberglass - light weight carbon fiber used minimally.
Designers still needed to 'hide' metal weights in nose to get balance right - adding to 'dead weight'.

Still a great plane for the price point and fun to fly - just do not expect a quick climb or power to spare
Oct 10, 2016, 02:48 PM
Admin Deluxe
Jim T. Graham's Avatar
Have you flown the plane Nova?
Oct 10, 2016, 03:08 PM
rcnova
Yes, bought the BNF on pre-order - one of the first to fly (after completing the factory required repair bulletins).

Look at comments on the main blog for the plane for more information.

Note: per video provided with the review above - at 4:03 - states that the plane "does not have a lot of vertical capabilities" plus additional disclaimers on the power system.

At 79.5 oz, this plane weights about 5 lbs - most 2.6m powered sailplanes weight much less. The wing loading of 12.1 oz/ft2 is the high end of a sailplane. remember the 5 lb plane is powered by only a 3S battery.
Last edited by Nova - K; Oct 10, 2016 at 03:31 PM.
Oct 10, 2016, 03:35 PM
NY Slope Dog
Wind Junkie's Avatar
I think the power is perfect for the intended purpose. I mean we are talking about a 100" span FOAMIE here.

You don't want to speed this one up, so adding more power would likely just get you into trouble.

And unless you're going for max endurance the weight is fine. I suppose you could remove any factory nose weight and sub in your own (giant) battery to compensate, but fo rthe sport and Sunday flyer I think the designers did a darn good job.
Oct 10, 2016, 06:05 PM
Sagitta Fanboy
Quote:
Originally Posted by Wind Junkie
I think the power is perfect for the intended purpose. I mean we are talking about a 100" span FOAMIE here.

You don't want to speed this one up, so adding more power would likely just get you into trouble.

And unless you're going for max endurance the weight is fine. I suppose you could remove any factory nose weight and sub in your own (giant) battery to compensate, but fo rthe sport and Sunday flyer I think the designers did a darn good job.
The power system is decidedly more anemic than the smaller Radians, in comparison to the weight of the bird. A 2m Radian or Radian pro can easily do 200m in 20-25s, the XL will not do that in 30s. It's perfectly fine for sport flying, but don't expect to have enough climb performance to be competitive at an ALES contest without some changes to the power system (again, unlike the 2m Radian which can fly ALES climbs just fine stock).

Numerous people have added more power with varying degrees of success. You can build it up to ALES-level power (in the 5-600w range) and get climbs equivalent to a 2m Radian, but you need to be more careful about how much extra power you add, as you can readily add power beyond what the fuselage can handle. Don't expect to get vertical performance like an upgraded 2m Radian can handle.

As to the weight, yeah, it's porky (Multiplex's 2.6m Cularis foamy builds up to 20-25oz lighter). This gives it surprisingly good penetration, but at the cost of poor light air performance. Note it does have a lot of wing area for its span, that's a relatively low aspect ratio wing and that preserves a lot of the Radian's legendary float despite the high weight. It will not have the low-speed handling issues of the 2.4-2.6m Multiplex foamies as its higher wing area gives it excellent low-speed float.
Oct 23, 2016, 01:06 AM
Registered User

Radian XL with Apprentice S receiver


I got to trim out a West Pasco Model Pilots Assoc. member's XL with the stock RX and DX9 TX. I used 5 flight modes: throttle stick has "Cruise" at low throttle, "Launch" at high throttle, and "Loiter" at half throttle. Moving switch D from 0 to 1 puts it into "Thermal" mode, and position 2 puts it into "Land" mode with full spoilers. Trim is set up so each mode has unique trim controlled by the stick's trim levers. I've marked the trim positions on the side of the fin as a check.

Since I've been spoiled with putting Apprentice S receivers and Eagle Tree Guardians into all my models for pitch and roll leveling I compared the two.

The Apprentice S receiver is much better than any unstabilized receiver. On launch using full aft stick the gyros maintain a 40-45 climb angle from a slow hand launch speed to its final 40? mph terminal climb speed. Once at altitude and with motor off the gyros maintain a pitch level attitude in Cruise and Thermal modes even when using rudder in thermal turns. The rudder gyros do a fairly good job in maintaining heading unless you override with stick or rudder trim. With Land mode and full spoilers you can trim in a 10 degree nose down descent or hold full down stick and then gyros limit dive angle to about 30-40 degrees. You can move the DX 6,7,8,9, or18 switch B to 1 (Intermediate) or 2 (experienced/off) if you want to do loops and high speed dives but this is risky for flutter.
Oct 24, 2016, 07:41 PM
DFS#000178
Rampage's Avatar
Can the spoilers be set up as roll spoilers? Or do they have to be activated together?
Oct 24, 2016, 07:47 PM
Sagitta Fanboy
Quote:
Originally Posted by Rampage
Can the spoilers be set up as roll spoilers? Or do they have to be activated together?
They're single servo activated, so no roll spoilers possible without significant modifications.

Also they're seriously inboard & only moderately effective so you likely would get little roll out of them.
Oct 30, 2016, 11:09 PM
Registered User
Libelle201B's Avatar
I agree with Wind Junkie, there is enough power for three or four descent launches no problem. I love its size as it's easy to see at altitude and would make for a very good for fun XC sailplane IMO. As mentioned it thermals very well even if a bit heavy and I have thermaled mine up from telephone pole height several times no problem. Also mine flew right out of the box with no trim adjustments. I have an old Ace thermal sniffer I may put in the XL at some point. I'm really happy with mine
Jan 23, 2017, 05:43 PM
Registered User
I have had this sailplane for about one month now. This is one heavy, heavy plane, motor is definitely underpowered, but does eventually get up there if there is no significant wind. It does glide nicely. The tiny spoilers are extremely effective. As mentioned in other's posts elsewhere, this plane can not handle winds much over 7 mph. I took her up the other day in 10 mph winds, and on launch she barely got up over 250 feet after a minute, my heart felt so heavy...I thought she was just going to give out and keel over in exhaustion. This is purely a fair weather bird. Quality, overall, is poor to fair. Over-priced in my opinion. I still can't get over how heavy she is for a foamy. The reviews in the magazines seem awfully biased IMO. Of significant note, the plastic inserts on the stabilizer where you place the set screws, cracked---and no, i did not over-tighten the screw. Horizon did send out a new stabilizer pronto, but this one also cracked after just a few flights, no hard landing incurred. When I called Horizon, they agreed to send out another stabilizer, but warned they were no longer going to stand behind this product----very disappointed. This is clearly a material quality/engineering issue. On the positive side, it does thermal nicely.
Jan 24, 2017, 12:05 AM
Registered User
Sounds like it's time to sell yours. I'll buy it hah!
Ballast is needed in every R/E sailplane in steady winds over 5mph. Especially winter flying. It's magic--try it. If you want vertical launches then get a warmliner. I put my Mobius camera on my friends XL and got some great shots. It's a bus--drive it accordingly.
Jan 24, 2017, 12:15 AM
Registered User
I have many many sailplanes and have tried out many more from 70's models on and haven't found one I like yet as much as my regular old parkzone radian--with ballast of course--and many of the simple mods.
Nothing beats parking, plugging in the wings, and flying. Simple is great. It helps that I have 4 superb sites within 5 minutes of my house.
Have to love the XL's ability to hang up there in zero sink tho.
Mar 13, 2017, 10:54 AM
Pro Bro # 2398
GassPasser's Avatar
First plane I seen in awhile that's getting my urge to get flying again.


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