ParkZone Sport Cub BNF with AS3X Technology

A go-to model for today’s sport pilot Article, photos, and video by Andy Griffith Abridged online product review. Full review in the November 2014 issue of Model Aviation.

Abridged Review

The ParkZone Sport Cub is modeled after the 100hp midrange Cub offered by Cub Crafters. With its 51-inch wingspan, the ParkZone Sport Cub lands right between its two siblings, the UMX Carbon Cub and Carbon-Z Cub. I thought that the Sport Cub would handle more wind than the UMX Carbon Cub, yet be small enough to transport fully assembled. The Sport Cub BNF includes an AR636 six-channel DSMX receiver with built-in Aircraft Stabilization 3 aXis (AS3X) capability as well as integrated flight data telemetry. Four micro servos are preinstalled and it has provisions for adding an optional fifth servo to actuate the flaps. Knowing how much fun the smaller and larger Carbon Cubs are, I was anxious to get started on the Sport Cub. I received the optional flap servo and the optional float kit with my review model, so I planned to assemble the Sport Cub on wheels, flight test it, and then convert it to a floatplane. The Sport Cub arrived extremely well packaged with no shipping damage. The parts were securely taped with a layer of packing material between the tape and the foam. After I unpacked the pieces, I sat down with the instructions. The manual is well written, nicely illustrated, and leaves little to chance. The Sport Cub’s assembly is easy and straightforward. I programmed my radio as the manual specified and followed the steps to make sure the gyro in the AS3X system was correcting in the proper direction. The last step was to put the Sport Cub on my balancer and set the CG. The Sport Cub has a large battery compartment that is easily accessed via a hinged hatch that is held in place with a simple catch. Holes along the fuselage centerline allow air flow to cool the components even in my hot Florida weather. With the supplied 1,300 mAh battery installed, I set the CG to the middle of the recommended range and used a marker to make a tick mark for the forward edge of the battery inside the battery compartment. There’s plenty of room to slide a battery around and access is excellent. Aside from waiting for the contact cement to set on the flap servo, the Sport Cub can be fully assembled in roughly 30 minutes. The lightweight optional floats are made from foam and covered on the bottom with hard plastic. There are no provisions for a water rudder, but airplanes this size generally don’t require one. Float installation is simple. The float kit comes with crossbraces, struts, and a hardware kit. I used the struts from the Cub kit and the crossbraces from the float set. The rear strut hard point and strut braces in the float kit can be discarded. The first day out with the Sport Cub was with the landing gear and bush wheels installed. The Sport Cub is big enough to be a larger park flyer, but it transports easily fully assembled. I drive an SUV and the Cub sits in the back with plenty of room to spare. Nature seems to know when I have an AS3X-equipped airplane because the wind was blowing at 10-plus mph when I got to the field and it increased as the day went on. The foamies and several of the built-up airplanes that were out early were already packed when I pulled out the Sport Cub. If not for my experience with AS3X, I wouldn’t have thought conditions were conducive for test-flying a new foam model. With a fresh battery, I headed out for a test flight. The manual indicated 4 to 7 minutes of flight time, so I set the timer to 4 minutes. Despite the breeze, the Sport Cub taxied easily on the paved taxiway. With the large bush tires, it had no issue taxiing in the mowed grass. With the Cub facing the wind, I slowly applied power and it came off the ground within a few feet. The model acted as though it needed up-elevator trim, so I brought it around, landed, and adjusted the clevis two turns on the elevator. With AS3X, it’s best to keep the transmitter trims at neutral to avoid interfering with the gyro operation. On the second try, I gave the Sport Cub a click of flaps and quickly advanced the power. The Cub was airborne in inches. I raised the flaps and, despite the winds, the Sport Cub flew easily. With ASX3, everything was under control and I didn’t feel as though I was fighting the wind. Control response and roll rate were excellent without being too sensitive. Although the Sport Cub didn’t seem to have the “hover at three-quarters-stick” power that the big Carbon Z Cub has, it will easily do loops from level flight. I love doing flat turns with full rudder and a little opposite aileron. Lowering the flaps to full, the Cub nearly came to a high-alpha stop in the 10 mph winds. With a little practice, I could do zero rollout landings with full flaps in the wind. When forced into a stall, the model broke straightforward and resumed flying almost immediately. I’m sure that was because of a combination of the vortex generators and the AS3X system. Because not everyone will install the optional flap servo, I tried several takeoffs and landings without using flaps. Although the rollout is a little longer and the landing speed slightly higher, the Sport Cub was extremely easy to handle without flaps. On wheels, the Sport Cub gets an A+. Based on the looks and comments of those who hung around to watch the flight-testing, more than a few of these will be at the field in the coming weeks. I have several E-flite batteries on hand from various projects so I did some experimenting. The large battery compartment easily accepts different-sized packs from the recommended 1,300 mAh all the way up to 2,200 mAh. The 2,200 packs flew at moderate throttle settings for 10 minutes and the Sport Cub absorbed the extra weight with no change in behavior. I turned the Sport Cub over to fellow club member Michel Hunter so I could get flight shots. Mike also did the flying for the online version videos and float shots.





Taxiing in the water without a water rudder can be a chore in the wind. Although the AS3X-equipped Cub can fly in the wind, between the lack of a water rudder and the wind-driven waves, it’s best to save water flying for calmer days. With or without flaps, the Sport Cub gets up and clears the water in moments. Flying with floats on is cumbersome, but not so much so that it detracts from the Cub’s performance. Landing on the water with floats is similar to flying with the landing gear on, but you need to flare properly. This sounds easy, but flying off of water generally means the pilot is standing on a bank or dock. Judging the water is different from the side-on perspective you have when flying off a runway. Misjudge the flare and the tips of the floats can hook the water. If that happens, the Cub will float away with its nose down in the water. The good news is that it’s foam so it floats! The Sport Cub is easy to transport, AS3X stabilized for great flight performance even in 10 to 15 mph winds, and a blast to fly. Order some spare batteries, the flap servo, and, if you have access to water, the floats when you get this airplane. The model is so much fun you won’t want to sit around waiting for packs to charge. The flaps emulate the short-field takeoff and landing capability of the full-scale Sport Cub and for the modest cost of the servo, the flaps are fun to play with. Converting from wheels to floats takes mere minutes and the Sport Cub seems tailor-made to doing touch-and-go landings in the water as the sun goes down at the end of a lazy day at the lake. —Andy Griffith

Specifications

Model type: Electric sport flyer Skill level: Beginner builder; intermediate pilot Wingspan: 51 inches Wing area: 417 square inches Wing loading: 11.4 ounces per square foot Airfoil: Semisymmetrical Length: 34 inches Weight: 2 pounds, 1 ounce Power system: 480-size brushless motor Radio: Four channel minimum; five channels for optional flaps Construction: Z-Foam Covering/finish: White foam with red painted trim accents Street price: $219.99

Test-Model Details

Power System: Parkzone 480 size 960kv; Parkzone 18 Amp Brushless ESC (included) Battery: E-Flite 3S (11.1v) 1300 mAh 20C LiPoly (included) Propeller: 9 x 6 slow flyer (included) Radio system: Spektrum DX-18QQ; Spektrum AR636 AS3X receiver (included); PZ SZ80 servos (included); DSV130M optional flap servo Ready-to-fly weight: 2pounds, 1ounce Flight duration: 4 to 7 minutes depending on throttle management

Pluses:

• Assembles quickly. • AS3X allows flying in wind that would easily ground most foam models. • The simulated window decals show an eye catching pilot silhouette. • BNF version can be in the air very quickly. • Parkzone gave Cub owners options for their two most common hop-ups; flaps and floats. • Happily accepts a variety of 3S battery sizes.

Minuses:

• None noted.

Manufacturer/Distributor

E-flite (877) 504-0233 www.e-fliterc.com Horizon Hobby (800) 338-4639 www.horizonhobby.com

Sources

Spektrum (800) 338-4639 www.spektrumrc.com