SPECIFICATIONS
Model type: Aerobatic/3-D
Skill level: Intermediate pilot
Wingspan: 48 inches
Wing area: 525 square inches
Wing loading: 13.8 ounces per square foot
Length: 48.5 inches
Weight: 3.75 to 3.9 pounds
Power system: 25-size, 1,000 Kv brushless outrunner motor; 60-amp ESC (included)
Radio: Programmable six-channel DSM2- or DSMX-compatible transmitter
Construction: Z-foam and plastic
Street price: $379.99 (BNF) $299.99 (PNP)
TEST-MODEL DETAILS
Motor used: E-flite BL25 1,000 Kv brushless outrunner (included)
Speed controller: E-flite 60-amp Pro switch-mode BEC V2 (included)
Battery: E-flite 2,800 mAh 4S 14.8-volt 30C LiPo (included)
Propeller: E-flite 12 x 5.25 (included)
Radio system: Spektrum DX18 Gen 2 DSMX transmitter; Spektrum AR635 AS3X DSMX receiver (included)
Ready-to-fly weight: 3 pounds 14 ounces
Flight duration: 4 to 6 minutes
PLUSES
• This second version of the Carbon-Z Yak has the brains (AS3X) to go with its brawn.
• The Yak 54 with AS3X can be flown as a smooth sport aerobat and with the flick of the mode switch, be instantly transformed into a hardcore, extreme 3-D-capable machine.
• Flashy Mirco Pecorari-designed finish bursts with color without sacrificing in-flight orientation.
• Plug-in wing and horizontal stabilizer halves can be removed for transport and storage.
• The main landing gear is post-stall capable and can tolerate poor landings by flexing instead of breaking.
MINUS
• Proper configuration of the AR635 receiver’s flight modes could be explained a little more thoroughly in the Yak 54 assembly manual.
I can’t begin a review of this aircraft without first giving a nod to its predecessor, the E-flite Carbon-Z Yak 54. Although it stayed on my wish list of models for many months, I only managed to enjoy it vicariously through the posts and videos of others.
With a high-rpm 4S power system that achieves a thrust ratio of nearly 2:1, a strong, lightweight Carbon-Z construction foam airframe, and digital servos pushing large control surfaces to extreme deflections, this semiscale Yak 54 seemed the perfect, smaller-size 3-D aerobat! Could E-flite really improve on an extreme-3-D-capable model that had almost everything going for it?
The design team at E-flite answered that question with an emphatic yes and decided that what this 3-D airplane needed was to be smarter. The company endowed the Carbon-Z Yak 54 with an AS3X-equipped Spektrum AR635 six-channel DSMX 2.4 GHz receiver.
This iteration of the Yak was christened with a new name: the Carbon-Z Yak 54 3X. Some people are suspicious of second-generation products and argue that the original version is always better, so it’s only natural to ask what other improvements, if any, exist in the new Yak 54 3X when compared with its predecessor.
The Yak 54 3X is not the first model released by Horizon Hobby to be graced with a trip through the creative studios of noted aircraft graphics design artist Mirco Pecorari. Art meets function in the form of a gold and maroon color scheme that is also in-flight-orientation friendly, thanks to large black bars on the underside of the wings.
E-flite stretched the main landing gear in order to create extra propeller clearance. The AS3X system can generate a higher net current draw because it constantly feeds corrective inputs to the servos. E-flite upped the output of the included 60-amp speed controller’s BEC circuit to a more-robust 5 amps of output to the updated, preinstalled digital servos.
Assembly
Releasing the Yak components from the box takes nearly as much time as assembling the model. The aileron linkages are endowed with ball links. A pilot figure and cockpit instrumentation graphics are preinstalled under the smoked canopy. The brushless power system is installed and wired. The sole step that requires adhesive is attaching the rudder to the vertical stabilizer using CA-style hinges.
The wing and horizontal stabilizer halves slide onto spars and are anchored with removable fasteners. The main landing gear assembly includes a pair of red wheel pants and white plastic gear leg covers. The entire assembly needs to be attached to the bottom of the fuselage.
Assembling the Yak 54 3X is quick and easy, but the time saved on it needs to be invested into ensuring that the Spektrum AR635 receiver is properly configured and that the transmitter programming does not conflict with the receiver’s settings and functionality.
E-flite includes a separate Spektrum AR635 receiver manual with the Yak and it is worth reading if you are unfamiliar with this jewel of a receiver. It would be even more valuable if the manufacturer would detail the receiver’s optimal setup in the context of this specific airplane, and include the information in the Yak’s assembly guide. As it is, the pilot must glean the necessary details from each manual.
Fundamental to properly setting up the AR635 is recognizing that it is primarily a flight mode-driven receiver. These flight modes are typically selected using the gear switch (channel 5) of your transmitter.
The first detail that must be observed when using the AR635 receiver is that the transmitter subtrims and trims must all be set at zero. Any necessary adjustments to attain a neutral state on the primary control surfaces (elevator, aileron, and rudder) must be made mechanically at the clevises.
The servo travel ranges of the three primary flight controls must be increased to 125%. Before configuring the transmitter’s dual rates, I recommend powering up the Yak to see how much throw exists on each control surface in both the normal and 3-D flight modes. Any necessary adjustments to the dual-rates settings in the transmitter programming can then be made. The assembly manual provides recommended throws for low and high rates.
I initially failed to consider the net effect that switching between the two flight modes would have on control surface throws. The Yak’s AR635 receiver does not come configured with much elevator throw when in the normal flight mode.
I had pinched down my low-rate elevator throw in my transmitter’s dual-rate programming so that the Yak’s elevator barely moved with full stick deflection. I had to reset the elevator dual rates to more appropriate throws.
Flying
After slipping the freshly topped-off 4S 2,800 mAh battery into the Yak, I flipped the mode switch on my new Spektrum DX18 Generation 2 transmitter to the conventional flight position.
Having a transmitter with voice capabilities is a relatively new experience for me and I like the way the DX18 can be configured so that it will audibly announce a mode change. It frees me from needing to remember which mode is assigned to each physical switch position.
The Yak’s battery hatch locks into place with a reassuring clunk, thanks to the strong retention magnets installed on its aft edge. With a range check performed and a final verification of proper control surface deflections, it was show time!
I typically enjoy flying scale aircraft and usually task myself with performing realistic-looking takeoffs involving a blend of slow, easy throttle application and minute amounts of up-elevator in order to establish a gradual angle of attack on departure. With the Yak 54 3X, you can throw all of that out the window! This high-performance airplane has plenty of watts stuffed into its cowl. Mashing the throttle to the stop and grabbing a bunch of up-elevator will send it tearing straight up into the sky!
The 1% of pilots whose skills qualify them as world-class performers may not like the AS3X system acting on their behalf, but the pilots who make up the other 99% (including me) will almost assuredly like what this system brings to the Yak!
From the moment that I began the takeoff roll, the benefits of the system were immediately observable. My Yak tracked straight down the center of the runway, needing minimal corrective rudder inputs. It exhibited uncanny stability as I cruised around the pattern making minor trim adjustments.
Aerobatics performed in this tamer flight mode are buttery smooth. The AS3X system does a great job of mitigating most of the effects of wind and turbulence, allowing the Yak to carve through the skies with impressive precision. Rolls, loops, knife-edge, and inverted flight maneuvers were executed with smoothness that I did not know my fingers were capable of generating!
After a surprisingly quick 5-minute maiden flight, it was time to bring the 3X in for a fresh pack. I let the aircraft get too slow on final and the Yak dropped in from roughly 18 inches, but the wire landing gear can absorb less-than-ideal touchdowns.
I have a photo that caught the botched landing. I was impressed to see that the gear deflected so much that it nearly made contact with the bottom of the wing, and yet it rebounded without breaking or even bending!
Flipping the flight mode switch to 3-D lets this Yak run unfettered. In this mode, the double-beveled control surfaces can deflect to their maximum possible mechanical positions. Although my 3-D skills will never earn me a spot on a factory team, I have been steadily expanding my repertoire of maneuvers. Adding the AS3X system to this airframe makes it an excellent model with which to boost ones skills and confidence. I was able to push through what had been sticking points when trying something new.
Less-advanced 3-D pilots like me can benefit from the way that the AS3X lurks in the background, ready to lend a hand when a pilot ventures into the realm of post-stall flight. I found hovers were much easier to maintain and noticed less wing rocking in high-alpha flight.
With nearly 235 watts per pound of performance on tap, the potent E-flite power system provides plenty of punch should you find gravity suddenly grabbing at the Yak.
I noticed some control surface oscillation if I allowed too much airspeed to build while in 3-D flight mode. Although a little bit of gain tuning in the AR635 receiver could effectively eliminate the oscillation, I found that faster flight maneuvers worked best if I switched to normal flight mode.
All of my flights were made from paved or hard-pack runways. Many pilots must fly off of grass airfields, and I am not sure that the diameter of the main gear tires is large enough for anything less than regularly manicured grass fields. Taking the wheel pants off may improve operations from grass strips. With the pants removed, it also becomes possible to go to slightly larger-diameter tires.
Conclusion
At one time I had high hopes of adding the original Carbon-Z Yak 54 to my hangar. I am now not the least discouraged about failing to do so before it went out of production. E-flite’s decision to use the Yak 54 as a 3-D vehicle with which to showcase its latest stabilization technology gave me another chance to add this model to my hangar—and I think the 3X version is more attractively equipped.
As an intermediate-level pilot working to expand my 3-D abilities, the AS3X-equipped Spektrum AR635 is the main improvement that makes this second-generation Yak 54 a sweeter deal. Checking or changing the flight mode gains in the AR635 receiver is slightly cumbersome.
The learning curve involved with properly configuring the receiver and your favorite transmitter might be steep for some pilots, but Spektrum’s new generation of AS3X-equipped receivers that offer a friendlier programming approach using a smartphone or tablet to access and modify parameters is hitting the market.
Several other subtle tweaks and improvements, including the glossy-looking graphics by Mirco Pecorari, make this Yak a sequel that surpasses the capabilities of the original. And in a wallet-friendly gesture, the BNF version of the 3X Yak actually comes in at a price point that is $20 less than the original version!
—Jon Barnes
barnesjonr@yahoo.com
MANUFACTURER/DISTRIBUTOR:
Horizon Hobby
(800) 338-4639
www.horizonhobby.com
SOURCES:
E-flite
(800) 338-4639
www.e-fliterc.com
Spektrum
(800) 338-4639
www.spektrumrc.com
