I am smitten with electric-powered, fixed-wing RC aircraft, and I spend way too much time looking at and lusting after that next must-have airplane. When I saw MotionRC’s video of the new RocHobby P-51 Strega, I was almost instantly in love with it!
I have a soft spot in my heart for warbirds. Many of the aircraft that fly at the Reno National Championship Air Races each year are retired warbirds. The extreme makeovers that these super-high-performance, modified vintage airplanes undergo is incredible.
There is every indication that RocHobby intends to create an entire series of models based on some of the more infamous Reno racing warbirds. The second model to appear in the RocHobby Reno Racers series is the P-51 Strega. (The first was a Sea Fury known on the racing circuit as Critical Mass.)
Manufactured from durable, ding-resistant Expanded Polyolefin (EPO) foam, this brilliant red-and-white model is capable of speeds in excess of 80 mph using the factory-installed, four-cell LiPo-powered brushless power system! The included electric servoless retracts sport metal trunnion struts.
Flaps are included and operate at more realistically slow and scale speeds than is typical. I especially love scale multiblade propellers and will usually forgo the improved speed and performance of a two-blade propeller for the visual accuracy of a three- or four-blade propeller.
The Strega comes equipped with a 101/2-inch diameter, four-blade propeller. Its outer tips are painted silver.
My normal unboxing buzz was at an elevated level as I slipped the Strega’s foam cradle from the brightly colored box in which it arrived. As I unpacked and inventoried the components, I marveled at the crisply colored graphics and paint. What an absolute beauty of a foam airframe!
Construction
Before assembling a new model, I give the assembly instructions a quick once-over. Assembly manuals have a way of making the process look as though it can be quickly completed in an hour or two. I usually find that it takes a long evening or two, even with many ARF-style kits.
Assembling the Strega took all of two hours, including transmitter setup and programming. The entire airframe goes together using seven screws: four to hold the wing in place, one for each horizontal stabilizer half, and a tiny screw to mate the two elevator halves.
The manual specifically calls out the size of fastener needed for each step, and spare fasteners of all sizes are included. RocHobby also includes a small plastic bag with spare fasteners, clevises, silicon clevis retainers, etc.
Attaching the control horns to all five control surfaces is probably the most time-consuming part of the assembly process. The manual goes into commendable detail and thoroughly covers the entire assembly process, leaving nothing to chance. A separate document covering ESC programming and troubleshooting is also included in the box. This is often omitted from foam ARF kits.
Finishing touches require using the included tube of contact cement-style adhesive. Foam wing fairings, used to blend the TEs into the sides of the fuselage, fit snugly into insets molded into the fuselage sides. A small amount of adhesive locks them into place. RocHobby includes plastic wing vortex generators and a pitot tube, which key nicely into place, thanks to impressions molded into the foam.
The included chrome spinner and four-blade propeller dress up the Strega’s nose and then some! Spare propellers and spinners are fairly priced and available from MotionRC. I found the gap between the rear of the spinner and the fuselage slightly wide at 3.0mm, but a quick trim of the motor shaft using a Dremel tool would be an easy way to decrease the gap.
MotionRC sent a pair of its Admiral 30C 4S 2,200 mAh LiPo batteries for use in this review. Coupled with my already existing inventory of 4S 2,200 mAh batteries, I envisioned extra-long, uninterrupted flight sessions with the Strega, without breaking for the flight batteries to recharge.
Trial-fitting some of the batteries from my personal inventory revealed that the Admiral LiPos are dimensionally svelte in the thickness and width department. Their dimensions, at 104mm x 33mm x 31mm (L x W x H), allow them to fit nicely in the available space.
Some of my existing LiPos (ElectriFly 30C at 101mm x 35mm x 35mm and FlightPower 30C at 105mm x 36mm x 33mm) are thick enough that the canopy hatch would not fully seat in place. Careful removal of a little foam might be able to rectify this, but suffice it to say that the available space in the battery bay is slightly tight.
I decided to use a full-range, satellite-receiver-equipped, seven-channel receiver (Spektrum AR7000 DSM2) for extra peace of mind, given the relatively high speeds that the Strega is designed to achieve. RocHobby provides a full set of recommended control throws and exponential rates, including flap throws.
The recommended CG is provided in the assembly manual. Placing the flight battery squarely in the middle of the space provided for it made my Strega slightly nose-heavy.
The Strega’s all-up weight is 48 ounces. Using my Eagle Tree eLogger, I ran the Strega up on a freshly charged flight battery. Holding it at wide-open throttle for a 15-second burst yielded a static reading of 600-625 watts.
RocHobby does not provide information or specifications regarding the Strega’s wing area. I calculated it to be roughly 308 square inches. Armed with this data, I calculate the Strega’s performance to be an impressive 200 watts per pound, with a wing loading of 22.4 ounces per square foot.
But enough of this number mumbo jumbo … let’s get this racer in the air!
Flying
I was slightly reluctant to break down the Strega for transport because of the way that I had arranged the abundance of servo wires within the square cavity located above the wing. Fortunately, the model fit fully assembled into the cargo compartment of my midsize wagon.
Model aircraft in this 1-meter-span range strike a nice balance. They are large enough for good in-flight visibility, yet small enough so as to not make excessive demands when it comes to storage and transport.
Pull the wing if you must. The four fasteners are perfectly aligned and reattaching the wing is stress free. Ensure that you get all of the connections correct when reattaching the wing
It would be nice to see RocHobby utilize a combination-style connector to combine all of the functions of each wing half into one connector, such as is used on some of the larger FMS warbirds. This all but eliminates the chance for making a servo connection mistake when repeatedly removing and installing the wing.
Once at the field, I always perform a quick range check and final verification of control surfaces. With my daughter poised to gather in-flight media, I taxied the Strega out onto the runway to check the tail wheel tracking. I typically set my rudder dual rates up so that high rates allow for fairly tight turns on the ground. I found that the Strega was chewing up most of the width of the runway and making a full 180° turn on the runway took careful planning and positioning.
I upped the throws on the rudder in my transmitter to 125%, which slightly decreased the turning radius. Any additional improvements will have to be undertaken mechanically by shifting the pushrod(s) around on the servo and control horns. The rudder and tail wheel are attached to the same side of the rudder servo horn.
Dropping the flaps to half position, I positioned the P-51 at the end of the runway and slowly eased the throttle forward. The Strega smoothly accelerated, pivoting up onto the mains as it built speed. A little preemptive right rudder was required to keep it tracking straight.
With a subtle pull on the elevator stick, it was off and climbing. I initially found it necessary to keep pushing the nose down as it climbed out, but I held off applying any trim until after I had pulled up the flaps and gear. With the flaps and gear stowed, six clicks of down-elevator had the Strega holding altitude with minimal stick input.
My first few flights usually involve plenty of slow-speed flying in order to set up the photographer for good photo opportunities. Exploring this flight profile early comes with the added benefit of familiarizing a pilot with how the aircraft will behave at slower speeds and when in the landing pattern. The Strega was impressively stable and docile while cruising at approximately half throttle. But slow-speed flight is not what this model is all about.
Upwind and at altitude, I firewalled the throttle stick and set the Strega up for a diving, high-speed pass down the runway centerline. Leaving the throttle at full, I carved several tight, oval patterns around the field to simulate a Reno-style Pylon race. The sound of the four-blade propeller and power system at maximum output is pleasing to the ears! The Strega stays nicely on track and is arguably one of the most stable aircraft that I have flown in several years.
My first flights took place on a day when the winds were almost nil, with temperatures in the high 60s. Under these nearly ideal conditions, the aircraft’s in-flight behavior inspired confidence.
On the second battery, I repeatedly brought the Strega in fast and low for photos. Each successive pass saw me easing it slightly closer to the ground, but the Strega never felt as though it had any surprises waiting for me. This airplane stays aimed where you tell it to go, and it so looks so good in the air! What is not to love about red, white, and chrome?
Flipping the gear and flaps switches, I made a few dirty passes for the camera and entered the downwind for landing. I like to keep my approaches large and lazy, with sweeping, gradual turns through each leg. I settled the Strega in on final, holding roughly 20% throttle until I crossed the threshold.
Slowly dropping the throttle further allowed the P-51 to settle in on the mains. The landing rollout was realistic looking, with the Strega staying up on its mains until the very last bit of velocity bled away
Although I have often been underwhelmed after the maiden flight of an aircraft I had long lusted after, the Stega’s performance was even better than I had imagined! The sight of it roaring around the field as I pulled elevator to make high-G, air race-style turns was phenomenal! The ease with which landings and takeoffs can be performed is icing on the cake!
Conclusion
Spare fasteners, an adequately detailed and comprehensive assembly manual with recommended control throws and an accurate CG specification, electric retracts with metal trunnions, flaps that deploy and retract at a near-scale speed, quick assembly … RocHobby is firing on all eight cylinders with this exciting Reno warbird racer ARF kit!
I definitely dig the way that the Strega grooves in flight. The look of the propeller disc created by the big, silver-tipped, four-blade scale propeller with the gleaming chrome spinner glistening in the center, is dynamite!
Unless you are willing to open up a little extra space in your battery bay, you may need to carefully select your 4S 2,200 mAh flight packs, to prevent their excessive bulk from inhibiting the removable canopy from fully seating to the fuselage.
I experienced no problems or failures with any piece or part of the Strega during the assembly or in flight. If your experience is not the same, I have read that MotionRC has excellent customer service.
Some may eschew multiblade propellers and prefer to roll back to a more efficient—although regrettably nonscale—two-blade propeller. There are notable gains should you wish to journey down this highway to high speed.
According to Tom Ellison at MotionRC, the company has been playing around with an APC E 12 x 12 propeller cut down to 11 x 12. With this propeller they have achieved speeds of nearly 115 mph with the Strega! This speed comes without any need to upgrade the factory power-system components, although minor modifications to the motor shaft may be necessary to make the APC propeller work.
Those who love fast Reno-style warbirds should grab a RocHobby Strega P-51 with haste.
SPECIFICATIONS
Model type: Scale warbird racer
Skill level: Beginner builder; intermediate to advanced pilot
Wingspan: 42.2 inches
Wing area: 308 square inches
Wing loading: 22.4 ounces per square foot
Wing cube loading: 15.3 (racer)
Length: 38.3 inches
Weight: 45 ounces
Power system: 3648-770 Kv brushless outrunner; 70-amp ESC with 5-amp BEC
Radio: Six-channel minimum required
Construction: EPO foam
Covering/finish: Factory-painted graphics
Street price: $199.99
TEST-MODEL DETAILS
Motor used: 3648-770 Kv brushless outrunner (included)
Battery: Admiral 30C 4S 2,200 mAh LiPo
Propeller: 10.5 x 8 four-blade (included)
Radio system: JR X9503 2.4 GHz DSM2; Spektrum AR7000 seven-channel DSM2 receiver
Ready-to-fly weight: 48 ounces
Flight duration: 5-7 minutes
PLUSES:
• The crisp, clean factory-applied graphics scheme is detailed, accurate, and looks fantastic.
• The stock power system and scalelike, four-blade propeller yield satisfying speeds of approximately 80-85 mph.
• A complete inventory of spare parts is available online from MotionRC.
• Switching to a nonscale, two-blade propeller can boost the Strega to triple-digit speeds.
MINUSES:
• The space available in the battery bay requires use of dimensionally thin 4S 2,200 mAh packs.
• As configured out of the box, there is a limited turning radius when taxiing.