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El Niño 3.9m

Product Code: EL-NINO
 (4 reviews)

Price: $2,044.68

3 in stock

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* Layup & Colour:


El Niño F5J is the latest and greatest 4m F5J plane to alight on planet HyperFlight. It is an extraordinary tour-de-force by the designer and manufacturer Alex Hoekstra. Informed by DLG build techniques the structure is exquisitely light, the surface finish is excellent and the aerodynamic detail design is exceptionally good. The F5J design requirements were modelled using XFLR5 and it was found that a model with a very high aspect ratio of 21.5 matched to a low 1000 g weight gave the best combination of small thermal climb performance and a good speed range. To achieve performance at these very low Reynolds Numbers a family of 11 specially optimised ultra thin airfoils were developed. Good handling was assured by incorporating a little washout. This has the added benefit of eliminating tip stalls in the bumpy thermals often found low down.

The phrase flies like big discus launched glider is rather overused and under attained. El Niño really achieves this goal, with the model clearly indicating the tiniest air currents and almost responding to your thoughts, rather than ploughing though the ether and lagging control inputs like a heavier and less nimble model. The excellent performance and lovely handling will allow audaciously low F5J starts to be made with confidence, and will enable a sport flier to outsoar the best.

The El Niño fuselage is a very streamlined, tadpole like shape, with a tiny bulge at the front to accommodate the motor and batteries progressing into a very slim boom. The fuselage front has the motor firewall molded in place. This needs to be reinforced with a 2 mm glass or carbon fibre firewall. The 19 cm glass fibre canopy hatch is securely fastened by carbon pegs to the front and rear. Removing it reveals fairly constricted opening with a maximum width of 28 mm. Fitting the powertrain, battery and RC will require careful planning. The nose is quite short so a slightly heavier powertrain and battery may be required to achieve the required centre of gravity. Simple and strong 3 mm OD carbon tube pushrods are ready fitted, changing to 1 mm wire at the rear, providing a conventional and slop free linkage to the elevator and rudder. The fuselage in front of the wing is made from glass fibre coloured black, so it is 2.4 GHz friendly to help with the RC installation, further back it changes to carbon fibre for maximum stiffness. The wing is mounted on a very slim and low drag pylon, to minimise the interference drag caused by the two bodies meeting. Similarly the tailplane is mounted on a small pylon, which is again nicely faired into the rear fuselage boom. The fin and rudder slide onto a spigot molded at the end of the boom. The fit of these parts is brilliant and perfect alignment is assured. The exceptionally light 17 g fin/rudder assembly only requires the rudder horn to be fitted to complete it.

The tailplane is of Rohacell/Carboweave spread carbon construction with a superb finish despite its 24 g weight.

The wing is of hollow molded construction, rather than using solid foam cores, as the manufacturer believes this is the only way to avoid the surface finish deteriorating due to the underlying foam bubble structure slowly deforming the surface. The front part of the wing incorporates a Dbox to improve the torsional rigidity despite the airfoil's 5.2% thinness.

We currently have two wing layups in stock:

Light - this wing layup uses 40 g/m2 Carboweave veil type spread carbon everywhere.

Strong - this wing layup uses a 60 g/m2 Carboweave veil type spread carbon on centre paerl and 40 g/m2 on the tip panels.

El Nino comes with all linkage and other items required for completion, apart from the RC and powertrain. A ballast tube is supplied capable of taking up to 280 g of lead, but this much is hardly ever required. Ballast slugs can be easily constructed by the modeller from fishing weights threaded onto a 1 mm wire.

The main things that separates El Niño from the competition is the low weight, the high aspect ratio nearly 4 m wing, the excellent aerodynamic design and the beautiful finish.

Check out these Dutch forum El Nino announcement and El Nino build thread for lots more info. Now supplied with well made wing bags.

(c) 2017 Neil Stainton.

El Nino Specifications
Wing span 3.93 m 155 in
Wing area 72.0 dm2 1116 sq in
Length inc spinner 163 cm 64.2 in
Flying weight from 1050 g 37.0 oz
Wing loading 14.6 g/dm 4.8 oz/sq ft
Aspect ratio 21.5
Wing airfoil Proprietary
EDA (dihedral) 6.4º
Spinner Diameter 28 mm
Centre of Gravity 100 - 105 mm from wing leading edge
Controls Rudder, elevator, ailerons, flap, throttle

El Nino Typical Weights
Fuselage inc pushrods 114 g 4.0 oz
Wing centre panel 270 g 9.5 oz
Wing tips 290 g 10.2 oz
Tailplane 24 g 0.8 oz
Fin 17 g 0.6 oz
Accessories 65 g 2.3 oz
Total structure 780 g 27.5 oz
Wiring 10 g 0.4 oz
Receiver 7 g 0.2 oz
Rudder servo 9 g 0.3 oz
Elevator servo 9 g 0.3 oz
Wing servos (4) 38 g 1.3 oz
Speed control 30 g 1.1 oz
Motor 77 g 2.7 oz
Prop & spinner 20 g 0.7 oz
Battery 70 g 2.5 oz
Flying weight 1050 g 37.0 oz

El Niño Recommended Servos
Elevator & rudder KST X08, Blue Bird BMS-A10H, MKS DS6100, MKS DS75K, MKS HV75K, MKS HV6100, Blue Bird BMS-106HV
Aileron KST X08H, Blue Bird BMS-A10V, MKS DS75K, MKS HV75K, Graupner DES428MG
Flap MKS DS6100, MKS HV6100, MKS HV6110, Blue Bird BMS-105HV

El Nino F5J Powertrain Recommendations
Powerline Micro 1010 3S 500mAh LiPo, 12x8 prop
Powerline Micro 1015 3S 500mAh LiPo, 15x8 prop
Leomotion L3007-5000R 3S 900mAh LiPo, 13x6 prop
Tenschock Viper 4450 5:1 3S 800mAh LiPo, 14x7 GM prop, 40A ESC

Note this is preliminary information and may be subject to change.

Reviews 4  

 Review by:

El Nino 3.9m

As a mechanical engineer, I am very impressed by the aerodynamic design of this glider. In my opinion, it has the best performance of any of the current large, F5J gliders. This is because it has the lowest aerodynamic drag combined with ultra light weight (mine weighs 1,048 grams), very thin airfoils for good penetration, and very tight circling capability.

I have an older Xplorer and one of the early Ultimas to which I can compare the El Nino. The Xplorer weighs over 2 KG while the Ultima and El Nino weigh about half that. The difference in flight behavior between these three are remarkable.

Being relatively heavy, the Xplorer flies fast, penetrates upwind very well, and responds quickly to control inputs. Its glide slope is quite good, but not as good as either the Ultima or the El Nino, and it flies down that slope faster than than the other gliders. Its relatively high weight and high flight speed means that it does not "float" as well as the others, and it is not able to detect and circle as tightly in light lift.

The Ultima is the ultimate floater. It flies very slowly and will turn extremely tightly. So in calm conditions, it has significantly better duration than the Xplorer. But the Ultima is useless in windy conditions. The Xplorer's greater weight and speed makes it vastly superior to the Ultima, which will only hover into any significant head wind, and it is knocked around severely by turbulence.

The El Nino is a much better all-around glider than either the Ultima or the Xplorer. This is because the El Nino is very light so floats well, but it has a very thin airfoil for speed. The result is that the El Nino will float well in light conditions, but penetrates into the wind almost as well as the Xplorer.

Generally the faster the glider, the greater is its sink rate. So fast gliders typically do not have duration performance as good as slow floaters. The El Nino is an exception to this rule. It has such low drag that its glide slope is flatter than any other glider I have experienced. As a result, it can be flown fairly fast while maintaining a very slow sink rate. Additionally, it can be slowed down for calm conditions and float virtually as well as the Ultima.

The higher air speed of the El Nino also translates into more responsive handling. The Ultima has very weak and sluggish handling due to its very slow speed. The Xplorer has good control response, but due to its weight, it just isn't quick and agile. By comparison, the El Nino is both agile and responsive.

In short, I find the El Nino to have the best all around performance because it has a very wide speed range, an amazingly flat glide slope, outstanding duration, indicates lift superbly, and has the best handling and agility. It is by far my favorite glider.

So why have I given it only a 3-star rating? Unfortunately the fit, finish, workmanship, and completeness are poor. A glider this expensive should be state-of-the-art in these areas -- like the Xplorer. The El Nino is a major disappointment and quite unsatisfactory. Compared to the Xplorer (which is the gold standard for fit and finish), the El Nino is a real mess and has a multitude of detail defects. be fair and objective, I will list some of the specific defects in the El Nino so you can see that this is not just a matter of opinion.

To begin, the servo pockets in the underside of the wings are not symmetrically placed. Those in my glider were randomly placed with differences in position between the right and left wings by as much as 14 mm. Obviously they were not fitted using a jig.

The servo pockets are too far aft in the wings. This makes it virtually impossible to anchor the servo trays to the spar, which is the best place to distribute the servo forces. Anchoring the servos only to the upper wing skins is not good practice and causes the wing skin to deform under load.

Another advantage to having the servo pockets up near the spar is that is the thickest part of the wing. This makes it possible to keep the servo arm completely within the wing so a flat servo wing cover can be used. This would eliminate any need for the bubble in the servo covers that were supplied in the kit.

The aileron and flap control horns are very well designed. They are thicker than those in other kits so they have a wider bearing surface to resist wear. The aileron horns are at 90 degree to the hinge line while the flap horns are 45 degrees forward of the hinge line. It is the correct way to design control horns since these surfaces are very different in their throws. Both the Xplorer and the Ultima could take a lesson from the El Nino.

The control horns are CNC machined -- but they are not completed. They are left in the base fiberglass, which requires that the modeler cut them free and sand off the rough edges and mounting points. The other models provide finished horns, why not the El Nino?

The holes in the horns are too large for the wire that is supplied with them. This results in an unacceptable amount of slop in the linkages. To fix this problem, you will either need to make new horns and drill the holes to the same size as the wire, or you will need to get larger wire and drill larger holes in the supplied horns to get a slop-free fit.

There are no gap seals on any of the El Nino's hinged surfaces. The Xplorer does it best with beautifully constructed, internal gap wipers. The Ultima comes with gap seal tape. The El Nino has no seals at all.

Although there are no gap seals on the El Nino, the manufacturer supplies a wide roll of plastic film that you can cut and to make gap seal tape yourself. It will be difficult, to cut the very long, thin lengths of film accurately so that it is about 10 cm wide and has parallel edges and looks good.

You must then apply a very narrow, thin, double-sided tape to the pieces you cut. Laying this tape straight and neatly is very difficult. Additionally the tape is too narrow (about 1 mm) to hold the film firmly in place. You must use two parallel rows of tape spaced about 5 mm apart to mount the plastic strips adequately.

In short, you not only have to apply gap seals yourself, but you have to make the gap seal tape. You cannot do it as well as commercial gap seal tape. On a glider this expensive, there is absolutely no excuse for this. The manufacturer should, at the very least, supplied a roll of commercial gap seal tape. But he really should apply it himself so that the wings come already fitted with it -- like all the other glider manufacturers do. Better yet, use internal wipers. I bought a roll of commercial gap seal tape so that I could do the job well.

The construction of the wings is not precise. When wings are made in molds, the layers of carbon, foam, resin, and other parts will normally be very consistent and the left and right wings will be virtually the same weight.

The left wing of my El Nino was 17 grams heaver than the right. When you pick up the glider, the left wing immediately falls towards the ground. To get this much weight difference between the wings requires truly sloppy workmanship. This is simply unacceptable in a glider with such an impressive aerodynamic design. What a shame that the manufacturer has such careless workers.

The wing/fuselage alignment pins and mounting bolts were not aligned. The wing and fuselage would not fit together when I got the kit. It required extensive modification to get them to fit. The wing tip alignment pins also did not fit.

I understand that the manufacturer has addressed this issue in his current production, but the fact that customers had to make him aware of the problem says volumes about the factory's quality control -- or complete lack of it.

The flat head bolt wing recesses were too deep for the bolts to be flush with the with the wing surface (they were recessed 1.6 mm). To make matters worse, they were not centered. This is only a cosmetic problem, but again shows careless workmanship.

The fuselage halves are not accurately glued together. They are out of alignment by 0.8 mm. This results in a step in the firewall, where half the firewall is further forward than the other half.

The step can be removed by carefully sanding the firewall so it is flat. But you you cannot sand firewall that is inside the fuselage. As a result, an internal step remains. When you bolt the motor to the firewall, the motor shaft ends up being cocked at a small angle -- it is not aligned with the axis of the fuselage. Therefore, the spinner gap will be different at different points around the fuselage.

This is not only unsightly, but the thrust line is not aligned with the fuselage. This causes the plane to pull to one side under power.

There are also steps in the wing tips. These cannot be sanded flat because alignment pins are already glued in place so you cannot use a sanding block to true up the entire surface. As a result, the wing tips do not fit flush to the center wing panel.

The canopy is held in place with a 3 mm shaft. This shaft is glued to the underside of the canopy. But the glue is too far towards the ends of the canopy so that the shaft is so stiff that it is very difficult to install and remove the canopy. The shaft should be glued closer to the center of the canopy so it is more flexible.

The shaft is glued to the canopy with huge, irregular lumps of glue that are very ugly and unnecessary. A couple of small drops are all that are needed.

There are many surface faults in the wings and tail apparently caused by dirt in the mold. There is one big glob of dirt actually in the skin. Sloppy, sloppy, sloppy! I could go on, but I am out of characters, so cannot write more. But you get the picture -- this is a great design that is ruined by terrible workmanship.

 Review by:

Apparently it's lighter than air..

What a remarkable model this is!
I went out yesterday to maiden it and was blown away by a couple of things..... was the first time holding it above my head to throw it, just like the countless times I've been throwing sailplanes and realised how really light this thing is. The numbers say one thing, but the reality of when its in your hand and above your head is something else entirely.

....she moves! And with remarkable ease too, yet she can be slowed down and change direction with such little loss of energy. This was a real first for me and something I only experienced with a good dlg. I thought my J planes were nimble but the El Nino is in a totally different category.

I launched it some 8 times for about an hour of flight time and not once did I feel intimidated by it's handling. CG at 103 worked but can appreciate why having it at 105 may slow her down a tad.
Some binding issues with Aileron/flap coupling but nothing sanding of trailing edges wouldn't solve.

Brilliant model Alex Hoekstra, thanks for creating it, I may have to get another one!

I bought El Nino No3. from Neil at Hyperflight as he was the only vendor who had them at the time. By doing so I learnt what a superb chap he was to deal with and made the whole task of payment, in the US, packaging and shipping an easy process. Thank you and I plan on being a customer for some time.

 Review by:

El Nino

The El Nino is an amazing performer. I currently fly an Xplorer 2.5 F5J, an Ultima, and two El Nino's. The Xplorer and Ultima are for sale. The El Nino indicates lift and turns like no other model I have ever flown.
The El Nino does not come as finished as an Xplorer or Ultima, so I would not recommend it for a beginner builder. I have both the light and strong layup versions. The light version is strong enough for almost any situation.
Both aircraft have Powerline 1015 motors and Castle 35amp ESC's, MKS DS 6100's for the flaps, and DS 75K's for the ailerons. Using the same methods as Hutton describes, I am able to get proper control surface throws with flat servo covers.
The El Nino's thin wing section really makes a difference in penetration. I fly in 15-20mph winds without ballast and never have a problem returning from downwind.
The high aspect ratio truly makes El Nino act like a DLG plane.
I have found taping the vertical stabilizer on the fuselage still allows the stabilizer to rotate slightly in flight. This was easily fixed by using a small screw to secure and index the joint.
I have not added a firewall doubler to my aircraft. I have found the molded firewall to be strong enough. Although I have only drilled the 4 mounting holes in the firewall, no cooling holes. I have found the motor runs hot, but even on 95F days I do not experience any over-heating issues.
El Nino is a wonderful aircraft.

 Review by:

El Nino

The El Nino is very nice piece of kit. The build quality is top notch. The surface finish is superb. Overall it isnít in quite the same pre-finished state as a Supra or Maxa, but itís up there with what you need to do to finish a DLG (which is the pedigree of the El Nino anyway). The one I have has the heavier (Textreme) centre panel.
Some comments on the assembly. The wings went together easily, I mounted the servos against the spar (with 5mm balsa pad) and 6.5 mm hole to centre on the flaps and 5mm on ailerons. I looked at the ServoRhamen frames and found that they put the horn too far back which would have required a blister in the cover. With the servos mounted as above, they donít need a blister. The trailing edge is stiff considering the 1.2mm wire used as push rods (there is a bit of bounce, but itís not a problem in the air). I used lighter wire than supplied for the servo extensions (Flaps MKS 6100, Ailerons KST 08).
The horizontal tailplane required a few strips of tape to level up with the wings. The supplied push rods are perfect but you need to reduce the amount of free wire at the Elevator and Rudder end. The connections to servos is as per the Tweagle, There isnít a lot of room for the servos in the fuselage, but horn length of 6mm is enough to get all the required travel.

Fitting the motor / ESC servos Rx and Batteries into the nose is a challenge. I used the 2.5mm thick mount plate from Reisenhauer gear box and Tenshock motor., with the Himodel 40A SB ESC. I soldered the ESC wires to the motor wires and tucked the connections alongside the motor. The Rx (Jeti 7REX) fits diagonally between the battery area and the servos. A 13x8 GM prop is more than enough. The El Nino can easily get to 250m is less than 30 secs (donít ask Ėitís a great way to lose points).
The model weighs 1115g with the 650mAh batteries and 1140g with 850mAh (Tattu / GensAce fit). Putting the El Nino together at the field is easy (and fast) compared to a Maxa, and the elevator doesn't need those little screws. Battery weight determines CG. The CG with the 650mAh battery is 103mm, with the 850 mAh battery 100mm. XT30 connectors are the go. With the motor / prop setup above it uses ~200mAh for a 10 minute flight, which suggests the current draw is no greater than 30A.
Flight characteristics are excellent. The El Nino is much more nimble than my Maxa, it gets around the sky with authority despite the low weight and handles winds of at least 20 km/hr without the need for ballast.

I like it very much. Itís not a model for first timers, but if you have experience putting together a DLG you wonít have any problems. You will be rewarded by the excellent handling and easy flight characteristics.

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