|Length:||60 cm / 23.6 in|
|Wingspan:||42 cm / 16.5 in|
|Construction:||Pre-printed, lightweight foam panel (profile), contact cement glue|
|Power:||G-110 Brushed Motor - Included|
|Propeller:||Ikarus direct drive 3.25” / 83 mm (pitch unknown) - Included|
|Battery:||Lithium Polymer 7.4volt, 350mah – 720mah - Not Included|
|Weight:||85g / 3.0 oz and up, depending on components – 3.9oz as tested|
|Speed Control:||Micro Brushed ESC, at least 5 amp with BEC - Not Included|
|Available From:||Ikarus USA|
It’s a perfectly beautiful summer morning and you are strapped into a front line, Sukhoi Su-27 Flanker. You come in for a slow, high alpha pass across the flight line where thousands enjoy the air show you are a part of today. Pulling out of the pass, you climb to perform a graceful turnabout followed by several axial rolls and a low-level, fast flyby. Suddenly, your flying buddies make a few remarks about the model, awakening you to the reality of your casual setting!
Well, reality is good - because you are flying an Ikarus Su-27 Shock Flyer. Instead of the multi-million dollar fighter and insane fuel bills back at the airshow, you paid very modestly for the pleasure. But you are still having a LOT of fun, and you’ll even be home for lunch in an hour or so, after a few more sorties.
|Radio Gear:||Transmitter, Sub-Micro Receiver, Two sub micro servos, “Elevon” type mixing capability.|
|Flight Pack:||Lithium Polymer battery pack, 2s (7.4 volt), 350-720mah class.|
|Speed Control:||Brushed motor controller of sub micro size and weight, appx. 5 amp capable|
|Consider the fact that the Su-27 is a light-weight indoor/outdoor model where weight is critical when choosing components.|
Ikarus really brought home a lot of fun potential with their line of Shock Flyer models. The basic concept was to provide quick-building, attractive, simple, light profile aircraft that excelled at indoor, park flyer and 3D aerobatics. The kits included good quality accessories, well thought-out construction and attractive pre-printed parts. A Shock Flyer kit also gave anybody the ability to build a great little airplane in only a few hours.
The Su-27 Flanker by Ikarus is a part of this line of fun, aerobatic flyers. The SU-27 conforms to this ideal except that it isn’t set up to do any 3D aerobatic work due to the mid-wing “pusher” motor location and lack of rudder control. What the SU-27 gives back in trade for the lack of 3D flight is a very distinctive looking and flying model with a flight envelope designed around confined spaces and of course the proven ease of Shock Flyer construction.
In this review I will cover basics and some finer points of construction, trimming and flying of the Su-27. There also will be videos along the way of the model in flight. I will also give summarized impressions of the building and flying experience as a final review.
When I received my SU-27 kit, I discovered a compact package and small parts count. I was impressed by the good-looking graphics printed on both sides of the airplane parts, as well as the thought that went into the interlocking parts themselves. The instructions, though brief, were presented with excellent photos and notes on nearly each step.
As I readied for what looked to be a very short build, I gathered the components needed to finish the Su-27. I used the following items to finish the kit:
|Futaba 6XA computer radio (any radio will do – computer mixing for elevon control is a big plus, versus an on-board, aircraft mounted mixer).|
|Berg 5 receiver (12g / .4oz)|
|Two Micro Servos (I used HS-55’s – 9g / .3oz ea.)|
|Polyquest 7.4 volt (2s), 600mah lithium polymer pack (31g / 1.1oz) purchased from Eflightpacks/|
|Ikarus Micro 2000, 5 Amp Speed Control (5g/.17oz with wires)|
The smallest receiver I had was a “Berg 5” receiver. It fit inside the supplied radio component fairing, however anything smaller would have been advantageous (size wise and weight wise). Additionally, the 9g/.3oz HS-55 sub micro servos I had lying around were somewhat overkill for this model. I would have preferred to use smaller, lighter servos for the sake of a few grams of weight savings and the fact that the Su-27 was certainly not going to need powerful servos. That being said, the HS-55’s still worked well, as expected.
The Polyquest 7.4 volt (2s), 600mah lithium polymer pack from “eflightpacks” was well-suited for the model, and was also applicable in other applications of mine, making it a great choice. The Ikarus Micro 2000 speed controller was also perfect for the brushed motor on the Su-27, being very light and just strong enough for the application.
Building the Ikarus Su-27 was a straight-forward experience. The basic construction of the depron foam airframe took me just over 2 hours, including interruptions, taking notes and pictures along the way. Even if you have a limited schedule, I assume many would be able to build the Su-27 in a single evening.
I familiarized myself with some of the symbols on the instruction sheet before starting. For example, one symbol instructed to “wet” glue two parts together, while another similar symbol instructed to let glue dry on parts for 10 minutes before sticking them together. In addition, some steps had several sub steps.
The Su-27 depron sheets were well-cut, and removal was simple. In a few isolated areas, I elected to use a razor blade to “cut” in corners or areas that didn’t immediately yield to the pre-cut part borders. In nearly all cases, I used the dull end of the razor blade to “punch” out the pre-cut foam notches that comprised the many “slots” in some of the parts. The kit consisted mainly of interlocking parts and was quite well thought-out for a strong, straight and quick build.
The first step of the build determined how flight control was set up on the model. The choices were: A) Expert: Elevons and Tailerons, or B) Novice: Tailerons only
I thought of these two options not as expert or novice, but as “conventional” or “3-D” style. Typical 3D aerobatics with the Su-27 were not possible during flight testing but this control setup resembled the style of flying involved with 3D. Either method produced a good flying model.
I went with “Expert”, elevons and tailerons, in the construction phase in order to give feedback during the flight report of both possible setups. Building the “expert” version, it was easily possible to remove the linkages and secure the elevons later with tape to try taileron only control. More on this later.
The Su-27 used simple tape hinges. In case you have never made a simple tape hinge, here is a quick explanation. A strip of tape is added along the junction of the elevon and wing (top surface). When you add this layer of tape, make sure you have a very small gap between the wing and the elevon in order to allow a downward deflection of the elevon. Then, the elevon is folded over forward on top of itself, as shown in the photo below, and a layer of tape is added to the bottom of the elevon and wing. The Su-27 instructions called for three short strips of tape to be placed on the bottom of the surface, rather than a full-length run of tape, presumably to save weight. Then the elevon was flexed back and forth to make sure the hinge was functional.
As the build progressed, the foam parts started to look like a fighter in very short time. The supplied glue closely resembled rubber contact cement and was simple to use. A small amount of glue did the job better than a large glob of heavy and ugly glue.
The servo installation called for the servos to be glued into position with the contact cement. I wrapped the HS-55’s with clear tape, put some glue in the mount area and placed the servos into position, being careful to not over use the glue here (prevent getting glue on the servo’s moving parts). I set aside the model so the contact cement could dry thoroughly before I placed any load on the servo’s glue joint during the linkage installation. During this break, I worked on the control linkages themselves.
The control horns were a unique design that grasped the control rods by folding over the rod and then used a small crew to hold the control rod firmly in place. This also allowed very easy control surface adjustment as needed later on. I saw right away that the control horns would be difficult to manipulate and get the set screw fastened while attached to the model. So, I chose to do this task before the horn itself was attached to the model.
The servo arm fasteners were similar to the control horn fasteners except they were not adjustable – they held the control rods in a fixed position. The instructions advised to use CA glue to affix the control rod to the servo arm fastener.
The instructions also advised on the airframe motor mount. This was very straight forward, except the instructions lacked any reference to the supplied motor “interference” suppressors.
This was one place where I jumped ahead of myself and followed the directions without thinking first. By the time I installed the motor onto the airframe, I realized I had not installed the suppressors. Fearing I’d melt the surrounding foam when I soldered the suppressors between the motor terminals and the case of the motor, I elected to skip this only because I had a full-range, strong receiver for the model. If you plan to use a “limited range” sub-micro receiver, then I’d advise using the suppressors and adding them prior to permanently mounting the motor.
With the servo mount glue dry, I easily fastened all the linkages and set the controls to zero deflection. I also began positioning all of my components in the “radio bay”. My receiver was on the “large” size for the SU-27, even though it is tiny compared to a Hitec 555 Micro receiver. It barely fit under the radio bay shroud foam plate... but it did fit with some re-adjustment of the plate mounting. I installed the speed controller next to the left-side servo (right side when looking at the model upside down). The tiny Polyquest 600mah, 2s pack from eflightpacks fit into the opposite side “bay” across from the receiver.
The instructions showed that the Center of Gravity position was located across the front servo cutout slot, as seen from the side of the model. Initially, glancing at the instructions, I thought the photo was referring to the aft cutout line. This quick assumption was incorrect. The proper place to measure CG was along the forward cutout line. This was one of the most important steps of the entire construction process, and I was glad I had double checked the instructed CG position prior to flying!
The model was essentially finished at this point. I gave the finished Su-27 a good look over, checking the security of the radio and battery mounts, double-checking the Center of Gravity, the radio linkages, and the control positions with zero trim on the transmitter (all surfaces essentially “flush” except for a very small, upward deflection of the elevators).
There was no mention of control throws or flight control trimming on the instruction sheet, so I started out with 100 percent servo travel with the control rods affixed to the appropriate servo arm “holes” as shown in the instructions. I also operated the controls, making sure I had correct mixing and control movements. I chose to use elevons coupled with elevons. For a right turn, the right elevon and taileron rose, countered by a drop in the opposite controls. A straight ahead climb raised all four surfaces. Due to the control rod/arm setups as shown in the instructions, the elevons moved less than the tailerons.
The radio range check was satisfactory both motor-on and off, to spite my mistaken omission of the motor noise suppressors. My final weight revealed the model weighing in at 3.9 ounces, or 109 grams. This was slightly heavier than what would be expected if a lighter receiver and battery were used.
After such a short build, it was already time to get out and fly this Russian jet. All flights were made outdoors with light winds.
Initial flights were made with taileron and elevon control coupling. Later flights were made with the elevon control linkages removed and the elevons were taped into a zero deflection position to test taileron only control.
My flying buddy Adam Kremers was volunteered (commandeered) into taking all of the in-flight photos, while my wife Donna was finally talked into taking the three video spots with the same digital camera. I was having issues with my regular digital video camera, so apologies in advance for the simple video clips.
Hand launches were very easy with the Su-27. The trick was to not grasp the jet too tightly! It is not a heavy or stoutly built jet, so the light weight foam structure does not need to be heaved aggressively. Using full power, I gently tossed the model forward, grasping the fuselage in front of the motor area. The result was a straight-ahead climb, giving ample time to get on the controls for a graceful climbout.
The Su-27 climbed well, but was not over-powered for extreme vertical zoom climbs. A good technique was to allow the airplane to climb at a moderate forward speed if altitude was desired.
With elevon/taileron coupling, if an aggressive climb was attempted at a slow speed, the Su-27’s nose raised but the climb rate and forward speed slowed to a near stand-still. This was an impressive low speed maneuver in it’s own right, but it did not get the aircraft climbing rapidly. A slightly higher forward speed and gentle pull into a climbing attitude produced a good climb.
With taileron control, it was possible to climb the model at a slightly slower forward speed, with a higher rate of sustained climb like any other conventional model. This was due to the fact that the wing "elevons" were not deflecting “upwards” like a flight spoiler when “up elevator” was held.
This was a specialty for the Ikarus Su-27 Shock Flyer, especially with elevon/taileron coupling. As stated above, aggressive high pitch attitudes (nose-up attitudes) allowed the model to really slow down to a walking pace. This required about eighty percent or more power to maintain altitude however. This was due to the high drag that was induced by the high pitch attitudes at low speed. Nearly all the excess thrust of the motor was used to overcome the drag and to keep the model airborne at altitude and at the slow speed. Power off descents at low speed were also impressive, as the model descended at a nose-high attitude and gentle descent rate. The elevon/taileron Su-27 had excellent manners in slow flight and was very stable. Roll control was still very assertive, even up to nearly full aft stick deflection.
The elevon/taileron coupled Su-27 would not stall like a conventional model. It simply mushed ahead and plowed through the air in a very nose-high pitch attitude and full aft stick deflection. When I tried to get the model to stall, the nose simply bobbed up and down slightly. Of course, I tried this three mistakes high on the first time.
With taileron only control, the model behaved slightly more conventionally as roll control began to get mushy while the speed slowed excessively. The pitch control was still good, and even better than the elevon/taileron coupled control. More accurate pitch control was required to keep the model from stalling as compared to the other control setup. The aggressive nose high, slow flight of the coupled control option wasn't quite so attainable, but taileron only control still got close.
Taileron only control yielded a slightly more conventional stall. The Su-27 had more pitch authority, and it was possible to stall the main wings at a higher speed than the coupled taileron/elevon setup. The stall was still gentle, and recovery was easily accomplished by reducing the pitch attitude, allowing the model to fly back into it’s normal flight envelope with minimal loss of control or altitude.
The Ikarus Su-27 was not a speed demon with the supplied brushed motor. It did fly at relatively faster speeds, however, as long as the model was flown in a “jet-like” manner (gentle maneuvering while going “easy” on the elevator control, or “G’s” as our imaginary pilot inside might feel). As soon as the model was “loaded up” with tight turns, the drag increased and the model lost energy and began to slow. This was especially true with the elevon/taileron setup.
With taileron only control, the model was more suited to faster flight and traded airspeed for altitude in zoom-like climbs well. The model also seemed to hold energy better in taileron setup, as expected.
Many jet style aerobatic maneuvers were flown with the Ikarus Su-27 that did not require rudder or tons of vertical performance. Any maneuvering in the “vertical”, like Loops, Split S’s, Immelmanns, or Cuban Eights could be accomplished by trading altitude for airspeed and so on, as the “stock power” Su-27 did not have excess thrust to initiate these maneuvers from low speeds and low level. Any rolling maneuvers could be conducted at nearly any altitude and in a wide speed envelope, as the Su-27 had a very rapid roll rate compared to many models. Overall, the stock motor powered Su-27 was a graceful aerobatic performer, only limited by available thrust.
The coupled elevon/taileron controlled model had a sluggish elevator feel compared to aileron feel initially. This was due to the fact that during up elevator command, not only was the elevator deflecting, but so were the elevons. The deflecting elevons reduced the lift of the outer wing but allowed very high pitch attitude while retaining control. Full servo travel worked best for elevator control feel.
Taileron control gave a very conventional elevator control feel to the Su-27. While pulling up into a climb, the model responded well to input and was very crisp at all airspeeds. Taileron control allowed a very balanced feel of the elevator as compared to roll control. Elevator control throws could be reduced slightly depending on tastes, but I still kept mine at 100 percent on taileron only control.
With coupled elevon/taileron control, the model had blisteringly fast roll rates at any speed. Reduced servo throws via "dual rates" on the transmitter for roll control would likely be desired by most flyers.
Taileron control gave a nicely balanced roll feel at all speeds, but was slightly sluggish during a stall, like any conventional airplane. I kept my servo travel at 100 percent for taileron roll control.
Landing the Su-27 was simply a matter of reducing power and maintaining a nose level or slightly high pitch attitude while allowing the model to descent gently. During the flare and on final touchdown, the model was moving very slowly and full aft stick travel raised the nose to approximately 20 degrees nose up, on touchdown. The gentle stall behavior and high pitch attitudes possible really made the landing a fun maneuver in it's own right.
I have not flown the Su-27 indoors, but I have flown this jet in front of my house and in a very small park near my house. The model was easily maneuvered in tight spaces, and the superior slow flight performance was really valuable in such flying locations. The Su-27 was clearly in it’s element in tight spaces.
Every single kit project has pros and cons. Ikarus has stacked the deck in your favor for a good experience though, and here are the bullet points.
Ikarus has put together a unique project in Su-27 Shock Flyer. It looked great in the air and on the ground, had very easy going flight characteristics and was well-suited for tight space / indoor flying with the supplied motor and suggested battery. The kit went together very quickly and was well-designed. The printed graphics on the parts were excellent.
Since it was a light weight model, using light weight components was important. I was satisfied with the stock power, using the Su-27 as a fun, tight space flyer where I flew the model confidently at places I wouldn’t dare fly my other models. If an aggressive performer were desired, then an upgrade to brushless power would be an easy option. (Feigao 12mm Brushless IPS Sized Motor or equivalent)
The two flight control options really added variety to this kit. Tailerons only provided plenty of authority for assertive roll control and pitch control. I thought the taileron only option flight control setup was better suited for “stock power” due to the fact that it placed a lower aerodynamic load, or less drag, on the airframe for basic control. I also believed the elevon/taileron control option would have really come "into it’s own" with a more powerful, light brushless power system installed. In this case, the four moving surfaces might have been superior, depending on tastes. Each option had it’s own merits.
If you are looking for something different in a small park or indoor flyer, the Su-27 certainly has a lot going for it. I recommend it as a nicely performing, unique model that gracefully blends jet fighter looks with wonderful small field handling.
|Apr 19, 2005, 10:50 AM|
Well, 109g RTF is really pushing it. My SU 27 weighs only 82g with Schulze Alpha 435 rx, 2 Dymond D5.4, Kontronik Mikro 10 ESC and 2 KOKAM 340HD.
27g less weight makes a huge difference in flight performance.
Even my Feigao powered SU 27 with 4A Hacker/Jeti ESC weighs only 98.5g - including a heavier ETEC 2s1p 450mAh pack.
|Apr 22, 2005, 01:43 AM|
|Apr 27, 2005, 03:32 PM|
SU-27 with smoke cartridge:
P.S.: See the difference in performance
|Oct 08, 2005, 08:14 AM|
I can't see how you cant get it to 82g though! (I use the same bettery)
|Mar 14, 2006, 03:49 PM|
Between my tx and crashed aircraft
Joined Mar 2006
How tight can this SU27 shock flyer turn?
The review mentioned that this SU27 shock flyer is good for slow speeds and small places.
I am wondering how tight a turn it can make without losing much altitude.
I am interested in flying it in a 30 foot by 60 foot area (~ 10x20 meters)
and I am pretty new to RC aircraft.
|Jul 20, 2006, 11:11 AM|
Boston NW, MA, USA
Joined Jun 2006
For a very good pilot, with the plane still light (my build weight was 3.4oz), it could be feasible, but probably not that fun.
|Jul 20, 2006, 03:01 PM|
Between my tx and crashed aircraft
Joined Mar 2006
|Apr 02, 2007, 07:38 PM|
i really wanted to get this plane, then hobby lobby stopped selling it.
were is a good site that also sells a good power package or set up recommendations?
|Aug 23, 2007, 04:00 AM|
Just finished building one of these babies Stock motor, standard micro servos, GWS micro Rx and Micro 5A ESC.
I've only got 800 mAh 2 cells at the mo, with them on AUW is about 100g, but I should be getting some lighter 430 mAh batteries today so that should put it at the right weight (ish). If the weather stays good maybe get a flight in later after work
|Jul 26, 2008, 12:19 PM|
Joined Mar 2007
Don't know if you check old threads like this, but just wanted to say thanks for pics. I am assembling the SU-27 and your info is a great help to expand on the limited instructions. Only problem I have is that you skipped over installing the control horns and running control rods. A couple of pics would be greatly beneficial to newbies like me. BTW, the model now comes with laser cut wooden horns.
|Jul 26, 2008, 12:47 PM|
this is the Review i was LOOKING for!!!!
i was on the hobby lobby web site the other day and came across this SU27. they stoped selling it a while ago and i was excited they are still selling it, but now i can't find the page!
who else here in the US sells this plane? i liked HL because of their combos
and is their a BL set up you could put on this?
|Aug 06, 2008, 06:51 AM|
I have the ''Blue Arrow'' version of this motor in mine and it flies really nicely at an AUW of 86g.
|Sep 10, 2011, 06:50 PM|
Believe it or not, I just got one of these yesterday already built (crashed and repaired many times), plus a second complete kit! My plan is to copy the kit using $Tree foam, then build it. I have all the other hardware and electronics. Thanks RCGroups for keeping this thread alive! Gonna build it stock initially, then go for the gusto with my brushless Feigao! Woo hoo! If no one objects, I will report back with my progress during the next couple of weeks. I'm jazzed and juiced to the hilt about this project.
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