E-flite Carbon-Z Yak 54 3X BNF - 2015/03
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 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 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.
More than new colors define this aerobat
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-red 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 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 increased the output of the included 60-amp speed controller's BEC circuit to a more robust 5 amps to power 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 use ball links. A pilot figure and cockpit instrument 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 must be attached to the bottom of the fuselage.
Assembling the Yak 54 3X is quick and easy, but the time saved needs to be invested in 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 receiver. It would be even more valuable if the manufacturer detailed the receiver's optimal setup in the context of this specific airplane and included that 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.
Important setup notes:
- Transmitter subtrims and trims must all be set to 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, power up the Yak to observe how much throw exists on each control surface in both the normal and 3-D flight modes. Make any necessary adjustments to dual rates after verifying actual throws.
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 in the normal flight mode. I had reduced my low-rate elevator throw in the 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 a freshly topped-off 4S 2,800 mAh battery into the Yak, I flipped the mode switch on my 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 to 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 perform realistic-looking takeoffs involving slow, easy throttle application and minute amounts of up-elevator 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 I began the takeoff roll, the system's benefits 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 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 I did not know my fingers were capable of generating.
After a surprisingly quick five-minute maiden flight, it was time to bring the 3X in for a fresh battery 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 as a sponsored pilot, 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 one's 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 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. A little gain tuning in the AR635 receiver could effectively eliminate the oscillation, but 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 grass airfields, and I am not sure 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.
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 beginning to hit the market.
Several other subtle tweaks and improvements, including the glossy-looking graphics by Mirco Pecorari, make this Yak a sequel that surpasses the original Yak’s capabilities. 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.
Conclusion
At one time I had high hopes of adding the original Carbon-Z Yak 54 to my hangar. I am not 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 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 primary improvement that makes this second-generation Yak 54 a sweeter deal. The receiver's gain adjustments can be cumbersome, and proper configuration requires time and familiarity with both the receiver and your transmitter. That said, the performance, stability, and the tweaks in this version make it a clear step up from the original.
—Jon Barnes [email protected]
Manufacturer/Distributor
Horizon Hobby (800) 338-4639 www.horizonhobby.com
Sources
E-flite (800) 338-4639 www.e-flite.com
Spektrum (800) 338-4639 www.spektrumrc.com
Transcribed from original scans by AI. Minor OCR errors may remain.
