RC Airplanes | Gliders | Helicopters Tx TESTED PG 82
AND • • • • •
XLF-207 Laminar Glider DJI Phantom 2 Vision ASK 21 Drawings Neat Fair Racing Down Thrust
PROFILE POWER+
VECTOR IN ON Tx-R HADRON WING
FEBRUARY 2014
USA & CANADA $6.49
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EXTRA 330SC BP
TABLE OF CONTENTS DEPARTMENTS
10 LEADING EDGE 14 HOT PRODUCTS 96 ADVERTISERS’ INDEX
PG 46 DISCOVER WHAT REALLY MAKES YOUR MODEL’S ELECTRIC MOTOR SPIN PROPELLERS.
97 MYSTERY AIRPLANE EVENT
BUILD
HOW TO
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NEAT FAIR RACING CHECKOUT THE FUN YOU TOO CAN HAVE RACING VINTAGE AIRPLANES FROM THE GOLDEN AGE OF AVIATION. Rob Caso
APPYING THE FINAL FINISH WE SHOW YOU HOW EASY IT IS TO ADD THE FINISHING TOUCHES TO THE DALLAIRE SPORTSTER. Jeff Troy
DOWN THRUST ALTERNATIVE
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TOM PROVIDES A PROGRAMMABLE ALTERNATIVE TO USING BUILT-IN DOWN THRUST IN YOUR AIRPLANE. Tom Wolf
AEROBATICS PART 11 LEARN HOW TO BUILD A CONTESTWINNGING FREESTYLE ROUTINE FOR YOUR 2014 CONTEST SEASON. Daniel Holman
COLUMN
PG 22 HELICOPTER TOTAL FORCE IS EXPLAINED IN THIS MONTH’S COLUMN.
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RC SPORT FLYER . FEBRUARY 2014
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E-POWER THE HOW AND WHY ELECTRIC MOTORS USE BOTH PERMANENT AND ELTROMAGNETS. Andrew Gibbs
50 HELICOPTER TOTAL FORCE SEE WHY TOTAL FORCE IS USED TO DESCRIBE THE ENTIRE OUTPUT OF A ROTOR SYSTEM. David Phelps
FEBRUARY 2014
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REVIEW
THE PEOPLES’ DRONE DJI’S PHANTOM 2 QUAD IS DESIGNED FOR DOING AERIAL PHOTOGRAPHY AND FPV RC FUN. Lucidity
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3-VIEW
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THIS LARGE-SCALE MODEL IS A COPY OF THE FIRST GLIDER TO USE A LAMINAR-FLOW AIRFOIL. Gene Cope
PG 68
ASK 21 GLIDER DRAWINGS
ESPRIT MODELS LAMINAR
WE DOCUMENT ONE OF THE MOST POPULAR TWOSEATER SOARERS THAT WAS EVER IN PRODUCTION. Hans-Jürgen Fischer
PG 82 PG 76 76
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FLYZONE HADRON CHECK OUT WHY THIS E-POWERED DELTA WING WILL LET YOU TAKE IT TO THE EXTREME. Wil Byers
HITEC RCD AURORA 9X TX RC-SF TESTS THIS NEW 9-CHANNEL RADIO TO SEE HOW IT FUNCTIONS AND PERFORMS. RC-SF Staff
EXTRA 90 E-FLITE 340SC BP 3D E-FLITE GOES BACK TO BASICS WITH THIS 330 TO GIVE YOU LOADS OF FUN 3D PILOTING. RC-SF Staff
PG 90 RC-SF.COM
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HOT PRODUCTS ALIGN M424 QUADCOPTER
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lign is well known for their T-REX helicopter series. Now they are introducing a new model quadcopter, the M424. Their new quad is a plug-and-play model. You simply plug in the batteries that come in the kit and your quad will be ready to fly. The new M424 requires no assembly or fine tuning the control system. It features unique quad-rotor layout, with an innovative exterior that gives the pilot a touch of high-tech feel. The M424 has controls that are similar to RC helicopters. However, this quad has very stable flight characteristics, making it easy to fly even for those without prior RC airplane or helicopter experiences. It comes equipped with an AT100 radio controller that utilizes 2.4-Gig automatic frequency hopping digital signal (AFHDS) technology to provide stable signal and resist radio signal interference. The controller can be configured for different flight modes too, so it will fit any pilot’s preference.
AEROFLY 2014 UPDATES COMING
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erofly currently offers and further develops the following applications. They tell us their next major version of aerofly FS for PC and MAC, will release at the end of 2014, and will feature: • More aircraft • The same aircraft now available in our mobile version, for example Airbus A320, Boeing 747-400, KingAir C90 GTx and Beechcraft Baron 58 • Navigation features like VOR and ILS • Increased system depth • Virtual cockpit interaction • Support for a larger area, which means switching to a geocentric world model. Some of the aircraft of the upcoming version are already available as add-on aircraft from their website aeroflyfs.com or as in-app purchases for the MAC version. The mobile version of aerofly FS will see shorter update cycles. As the development of their desktop version progresses they will add new aircraft and
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RC SPORT FLYER . FEBRUARY 2014
Distributor Align RC USA 3626 Briggeman Drive Los Alamitos, CA 90720 Phone: 562-598-4700 alignrcusa.com
Whether you are a new or a seasoned pilot, the M424 Quadcopter provides an RC flight experience that’s different from conventional helicopters. It is easy to fly, fun and quick for you to learn how to control.
Specifications Diagonal distance 240 mm (rotor shaft to rotor shaft) Propeller width 140 mm Height 52 mm Weight (w/o battery) 80 g Weight (w/ battery) 95 g
Price $109.99
Distributor IKARUS-USA 1214 SW 39th St. Cape Coral, FL 33915 Phone: 239-540-0067 aeroflyfs.com
new functionality into the mobile version as well. aerofly RC 7 aerofly RC 7 is now available. It builds on their success with aerofly5 RC simulator and adds new exciting features, models and sceneries:
• Improved flight dynamics for more realism • Model scaling feature: increase or decrease the model size • Flying aids: F3A-grid, position guides, flying trace, ground view, etc. • Quadcopter support • Over 200 models and 50 sceneries
ESPRIT TYPHOON
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he Typhoon is one of a new generation of full composite, hollow-molded sailplanes. This sailplane is designed and built to be extremely lightweight, with superb strength and full competition capabilities. The Typhoon comes as a completely prefabricated glider. It has a two-piece, hollow molded, carbon fiber reinforced wing, which incorporates a slight amount of dihedral, with beautifully curved leading edges. The controls have live hinges and wipers. The wing is incredibly strong and it uses a square, carbon fiber joiner. The gel-coated, fiberglass/carbon reinforced fuselage is 2.4-GHz friendly—it has enough room to accommodate the electric motor system
Distributor
and up to 4S-size battery. The canopy gives easy access to radio gear and battery. Typhoons are designed to employ ailerons and flaps mixing to enhance soaring and speed. The carbon fiber reinforced elevator bellcrank has been factory installed. Also the servo wing pockets come carbon reinforced and prefinished. All surfaces have been flawlessly pre-painted in the molds.
Esprit Model 1240 Clearmont St NE, Unit 12 Palm Bay, FL 32905 Phone: 321-729-4287 espritmodel.com
Versions Fiberglass It is a standard hollow-molded fiberglass construction reinforced with carbon fiber—recommended for sport flying. Carbon The model’s wings are carbon cloth, and the fuselage is reinforced with carbon from the leading edge of the wing to the tail— recommended for the serious competitor.
O.S. ENGINES GT15
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.S.’s GT line of gasolinepowered engines offers plenty of power and fuel economy that make them favorites among flyers of all RC aircraft sizes. Those attributes are found in the new, compact GT15 gaser. The PD-08 pump-equipped carburetor delivers fuel consistently at any attitude or altitude, and the engine’s IG-06 ignition system provides dependable starts. The GT15 is perfect for you to mount the GT15 in any .60 2-stroke or .90 4-stroke-size model. It will let you enjoy all of the advantages of gasoline power, and will do so at an affordable price.
Features • Offers power equivalent to a .90 4-stroke or .60 2-stroke glow engine, with the superior fuel economy advantages of gasoline. • Features the same mounting pattern as the 65AX. • Specially designed O.S. carb makes tuning a breeze and delivers excellent throttle response; it comes equipped with a regulator and pump. • A special roller bearing on the large end of the connecting rod allows for 50:1 oil/fuel mixture. • Includes the compact IG-06 ignition module. Price
(OSMG1515) $349.99
Specifications Displacement Bore Stroke Rpm range Output Engine weight Ignition Module Muffler Requires
0.91 in.3 (14.95 cc3) 1.091 in. (27.7 mm) 0.978 in. (24.8 mm) 2000–11000 2.37 hp @ 15,000 rpm 22.26 oz (631 g) 3.35 oz (95 g) 6.28 oz (178 g) gasoline/oil mixture
Distributor Great Planes P.O. Box 9021 Champaign, IL 61821 Phone: 800-637-7660 greatplanes.com RC-SF.COM
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EVENT HOW TO
FAIR AIR RACING SOCIETY GOLDEN AGE RACERS TAKE TO THE SKIES AT NEAT FAIR 2013
BY Rob Caso
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njoying the near perfect flying weather, while watching the noontime demonstration flights at the 2012 NEAT Fair (the annual all-electric event held in the Catskills of NY), Thayer Syme approached me and a few other modeler friends with the idea of holding a demonstration pylon race at the 2013 event. The event would feature spec-built Golden Age racers. The idea here was the models would be mid-sized so as to be large enough to be seen, would all be in about the same scale and have roughly the same flight performance. It would be a builder’s and flyer’s event, with all the entrants being required to construct a model of an actual racing airplane built between 1920 and 1939—the so called “Golden Age.” The models were to be built from a kit, from plans or be an original design. In other words—no ARFs! Now, before you fire up a letter to Wil, I personally like ARFs and have a number of them—and so does Thayer. They certainly have their place in the RC community. The thrust of Thayer’s idea, however, was to encourage some traditional building and to see what everyone came up, if they started with a clean sheet of paper. While the event’s
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fanfare would be augmented with scale-like pylons, fluttering banners and, hopefully, good weather, we agreed that there would be no “real” racing. That was because running an RC model around pylons at speed in a crowded sky is a lot harder than it looks. And, presumably, the modelers would be risking quite a bit of building time and effort invested in their entries. Thayer’s idea was somewhat risky as the event’s success hinged on not only having nicely built and flyable racers, but also on having enough of them for a reasonably complete field. In the end, there were seven models presented, all very nicely built and all in period correct colors and livery—just enough for a convincing race. We even managed to get Tom Hunt, the director of the NEAT Fair, to hazard an entry. We also allowed one exception to the scale racer rule, enthusiastically including Paul Dixon’s entry, a 52inch Daddy-O, nicely built from the Stevens Aeromodel kit. Although not a scale model, its lines are clearly representative of the Golden Age air racer genre. During the last month or so before the NEAT Fair this year, the entrants were in a building and
finishing frenzy, with Thayer bringing up the rear by having to finish the Caudron’s canopy at the event! Nevertheless, we got our models built and test flown prior to “Zero Hour” and all the entries were very nicely built and appointed, almost as if they were being made ready for a static event and not a dog-eat-dog demonstration race. It was good fun on the e-mail thread the month prior, with the modelers publishing progress photos and reports, offering building and finishing tips along with the obligatory off-color commentary and racer flappery. Upon seeing the line up at NEAT, it was clear that Thayer had picked quite a talented group of modelers. RACERS Entrant ZEKE BRUBAKER ROB CASO PAUL DIXON TOM HUNT CHRIS PARENT THAYER SYME MIKE TULLY
Airplane Howard Pete Hall Bulldog Daddy-O Percival Mew Gull GB Model X Caudron C.450 Heath Baby Bullet
After the NEAT Fair, we surmised that a similar event could easily be held at the club level. And while
Constructed from foam core and painted and assembled the day of the show, no vintage air race would be complete without pylons. RC-SF.COM
23
BUILD
DALLAIRE SPORTSTER GETTING READY TO CROSS THE FINISH LINE
BY Jeff Troy
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s polyester fabric fuel-proof? Yes, but it isn’t dirt and grime-proof. Fuel and other nasties may not be able to attack and destroy the fabric, but if the fabric is not sealed, these undesirable elements can, and will, become lodged in the weave. The ideal product to seal the fabric
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is thinned, clear nitrate dope, which when brushed, will encapsulate the fibers of the fabric, seal the weave, protect from fuel and grime aggression, and provide an excellent pre-primer base for nearly any type of paint or topcoat you might choose to apply.
My 108-in. wingspan Shive Specialties Dallaire Sportster has been covered with natural (white) Super Coverite®, and trimmed with the same material in red, white, and blue. I won’t be painting any colors over the surface, but I will be applying two coats of clear dope and
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Polyester fabric is fuelproof, but dirt and other nasties can become lodged in the weave to destroy the beauty of your model’s finish. Two coats of clear dope, thinned 50-50, will seal the weave and prevent dirt and grime from sinking in.
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Starting with the smallest component, in this case, the vertical fin, begin the dope application process by brushing along the edges of the trim work. Keep the brushstrokes wet, but don’t get sloppy.
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When the edges have been treated and the dope is still wet, coat the entire surface of the component, working from root to tip with the grain of the fabric.
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Repeat the dope application process for the wing. The stripes and trim panels are much larger, so try to work quickly so that the dope doesn’t dry before you’re ready to dope the entire panel.
one coat of clear LustreKote® to seal the fabric and add a little extra fuelseepage insurance to the edges of the airplane’s fabric trim colors. Here’s a word of warning that goes beyond what you can read on the product labels. This stuff smells, and by that, I mean it really smells. You should work outdoors wherever possible, but if you can’t, at least open a window and crank up a good fan to push out the fumes. I have a wife and daughter who also build and fly model airplanes, and none of us seem to mind the smell of dope. START HERE You can start the dope application over any airframe component you choose, although it’s a good idea to select one of the smaller
components. Doing so will allow you to get a feel for brushing dope before you attempt to apply it over a larger surface—like the fuselage or wing. I suggest beginning with the rudder or vertical fin. Clear dope and dope thinner are available from Midwest Products and the SIG® Manufacturing Company. One quart of each will yield more than you’ll need for two coats over the big Dallaire. Pour equal amounts of dope and dope thinner into a sealable glass jar, and mix them thoroughly with a scrap stick or a length of dowel. Dope brushes are available in hobby shops, although many are notorious for leaving hairs behind while you work. You can pick them out with a hobby knife before the
dope dries, but it’s wiser to spend the extra cash to purchase a high-quality brush from a reputable art supply store or home goods store. A flat brush approximately one inch wide will do nicely. Start by brushing along the edges of the trim work. Follow the pattern of the trim, and keep the brushstrokes somewhat on the wet side. Before the dope dries, complete the surface application by brushing with the grain of the fabric. In the case of the fin, stabilizer, elevators and rudder, that would mean brushing from root to tip or tip to root, your choice, but keep the brushstrokes going in the same direction, working wet but not sloppy wet. Now that you’ve become a pro RC-SF.COM
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HOW TO
THROTTLE-TOELEVATOR MIXING A SIMPLE ALTERNATIVE TO ENGINE DOWN-THRUST BY Tom Wolf
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To begin the programming process, select the PROG MIX 1-8 menu item, as shown for this Futaba 10C transmitter, which is found on page one of the Advance Menu. RC SPORT FLYER . FEBRUARY 2014
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The Futaba 10C radio has eight programmable mixes, four are normal mixes, and four are curve mixes. In this case we are selecting PROG MIX 5, which includes a mixing curve.
R
ecently I was helping my good friend, John Fodor, test fly his new Piper J3 Cub. During the initial test flight we found if the Cub was trimmed for level flight at a midpower setting, it would enter a very steep climb when full power was applied. Conversely, if it was trimmed for full power, it would enter a rather steep dive when the power was pulled back to idle. We could find no elevator trim setting that resulted in acceptable flight characteristics over the entire throttle range. Clearly this was an unsatisfactory condition that required correction before the Cub would be ready for regular flights. As we found with John’s Cub, many high-wing airplanes have a pronounced nose-up trim change as the engine throttle is advanced. The traditional method for trimming the airplane to mitigate this pitchtrim change is to add engine downthrust. For some airplanes, the amount of down-thrust required to maintain acceptable pitch trim for both low and high throttle is substantial. Unfortunately for John, the cowl was already fitted to his airplane and adding the required amount of engine down-thrust would result in cowl fit issues. It also meant he was done flying the Cub for the day because completing the down-thrust modification was going to require considerable time in his workshop. To minimize John’s pain, we explored an alternative that was
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This is the page one menu for PROG MIX 5, which is set up as aileron-to-rudder mixing, and a zero percent mix for all mix points as the default. The mix is also inhibited as the default condition.
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much simpler to implement than adding down-thrust. This fix also allowed John to enjoy flying the Cub for the remainder of the day. IN THE RADIO A much simpler method of dealing with this trim change is to utilize your radio’s programming capability to add some downelevator trim as the throttle is advanced. Utilizing a programmable mix that includes a mixing curve allows for the application of the proper amount of elevator trim for any throttle setting. The flexibility associated with using a mixing curve is quite different from what is achieved via a fixed amount of down-thrust, which generally is optimized for full throttle operation. The use of radio mixing has two significant benefits: First, unsightly, non-scale down-thrust can be avoided. Second, this method provides a much quicker and simpler trimming process to achieve the desired pitch-trim for all throttle settings. This article will describe the steps required to program pitchtrim compensation for a Futaba 10C radio, but the principle is the same for any radio that has programmable mixes, with multi-point curves. INITIAL TRIMMING To facilitate determining the appropriate mixing values, we need to establish a baseline flight condition and then adjust the control
The page two menu for PROG MIX 5 has these settings for the default condition.
RC-SF.COM
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HOW TO
AEROBATICS PART 11 HOW TO BUILD A FREESTYLE ROUTINE BY Daniel Holman
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utting a contest-winning freestyle routine together is one of the most difficult parts of preparing for competition for me. It is definitely so for the Extreme Flight Championships. Making it to the winners’ circle for such a competition not only requires exceptional piloting skills, but a freestyle routine that will showcase them, by way of the airplane, in an impressive and attractive way. This is especially so considering the pilot gets only four minutes to impress the judges with a routine! Flying aerobatic RC airplanes and music are the two hobbies. For me, putting them together seems very natural and always presents an
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enjoyable challenge. In this issue, I am going to take you through the process of building what I consider to be a good freestyle routine. I’ll share some of my techniques for doing so. BASIC ELEMENTS In any major freestyle competitions, the basic elements of a freestyle routine are the same. All routines must be four minutes long, and be choreographed to music. The maneuvers flown in a freestyle routine need not be presented to the judges prior to the flight. Also, the music and maneuvers to be flown are the choice of the pilot. Considering these rules, a pilot
could theoretically use one song, with a length of four minutes. They could simply takeoff and “wing” the whole flight. However, such a performance will not get a pilot very far in the competition, even if they have excellent piloting skills. If not, then what must be included in a contest-winning freestyle routine? You need to first understand what is included in the freestyle judging criteria. Here is my take on each judging segment. Note that some contests will use a slightly different criteria, but most are similar. For this article, I will explain the XFC’s judging criteria.
TECHNICAL MERIT The technical merit of a freestyle routine is based primarily on the pilot’s use of the aircraft’s entire flight envelope, including fast, high energy maneuvers, as well as slow and smooth figures. Also, the pilot’s ability to use the airplane’s gyroscopic forces, P-factor, etc., fall into this category.
This picture shows the line of airplanes as XFC competitors waited their turn to put in another practice flight right before the competition started.
MANEUVER EXECUTION Although every segment of scoring is important and works together, the single most important is execution. Often new competitors come to a competition thinking they will place well based on the fact they can fly more maneuvers in four minutes than they usually see at a contest. This is a huge misconception because a well-designed freestyle routine is all about quality, not quantity. Consequently, throughout the routine the pilot must show his or her ability to perform all types of maneuvers—one near-perfect maneuver will score higher than two sloppy maneuvers that were performed in the same amount of time as the one. I cannot stress enough the importance of making every maneuver count. It is crucial if you want to win freestyle contests. Although the pilot must fly many back-to-back maneuvers, each maneuver must be clearly and cleanly defined in order to earn a
good score from the judges. Let me underscore then, that when you are designing a freestyle routine it is best to always use maneuvers you are comfortable flying. You must be skilled such that you can perform them consistently and fly them accurately. It is better to leave out a maneuver you aren’t comfortable flying, than to make a big mistake attempting to perform it. Again, you must make every maneuver count! VARIETY, AXES, PATHS Every freestyle routine must use good geometric components and figures. A good way to understand this is to imagine the airplane leaves a trail wherever it flies through the routine. At the end of the routine, what does the airplane’s trail look like? Ideally, the trail should fill the entire flight box, and do so with maneuvers on every axis. An example of a sequence of well-place maneuvers may be that you fly a fast-rolling loop that is followed by a slow-rolling circle. After the rolling circle, you’ll perform a square loop, with integrated point and snap rolls. Depending on the music the maneuvers are flown to, it is likely best to perform the rolling loop on the right end of the airfield
Here you can see an example of different ways to use each axis of the flight box during a freestyle routine. In all freestyle competitions, the pilot is judged heavily on his or her use of the entire flight box and every axis.
PRECISION AND HIGH SPEED FLIGHTPATH
Low 3D area Pilot box
Judges panel RC-SF.COM
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COLUMN HOW TO
The model is covered in Profilm (Oracover). The trim and markings were hand cut from the Profilm material.
E-POWER IT’S ALL ABOUT MAGNETIC ATTRACTIONS
C
LIPPED-WING TAYLORCRAFT This month’s model is an expertly built, quarter-scale copy of a 1965 clipped-wing Taylorcraft. It was built by British modeler Martin Tremlett. Martin designed and built
his 82-inch wingspan beauty over a period of two winters. The model was originally fitted with a 1.20-cubic-inch glowpowered engine, although it never flew with glow power because of vibration problems. They caused
Martin is warming up the Taylorcraft’s Continental C90. The slightly cheeky, pert nose of the Taylorcraft is very appealing.
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RC SPORT FLYER . FEBRUARY 2014
BY Andrew Gibbs Martin to therefore replace the original power system with a clean, quiet and practically vibration-free electric power system. The chosen system consists of a 9-cell 6000-mAh LiPo pack, and a German made Plettenberg Xtra 30-
Hid inside cowl is the German made Plettenberg brushless, outrunner motor. It is nearly invisible from outside.
Here is a close up of the tailplane’s bracing wire. All the details of this lovely model have been beautifully executed.
The scale detail around the prominent roof area adds a lot to the impression of realism for this Taylorcraft. The Taylorcraft’s tail is nicely done too. The bracing wires are soldered assemblies that are attached to the aircraft with small bolts.
10 motor. Control is delivered by a 70-amp opto-isolated Jeti ESC. The motor first turned an APC-E 19x10 propeller, which had it running at 5700 rpm. The current for the system was 41.8 amps. Martin also tried a Rasa 20x11 carbon propeller. Static testing revealed little difference between the two propellers. The corresponding figures for the Rasa are 5600 rpm and 42.8 amps. Martin found that the slightly higher pitched Rasa propeller gave the model a considerably improved flight performance. With it, the Taylorcraft would fly a large loop easily starting from the straight
and level flight, without the need to dive the model to gain airspeed and momentum. This shows the value of testing different propellers with an otherwise unchanged power system—doing so can yield a simple and inexpensive way to gain performance. Of course, any time the components of a power system are changed, it is always worth measuring power to make certain all the components are operating within their limits. With the Rasa propeller, the Taylorcraft’s high-power is around 1300 watts. Since the model weighs 13.2 lb, this is close to 100 watts per
Designer and builder Martin Tremlett looks justifiably pleased with his model. Every detail of this fine model has been beautifully crafted.
pound. For a cabin type monoplane this represents a fairly generous power loading. Note that the Taylorcraft’s power system runtime is about six minutes when power management is used. Flight times are lower if more power is used. The model’s structure closely follows that of the original. It is constructed of balsa, plywood and Cypress wood. Martin reports the Cypress is a very good substitute for spruce. He says it is not only lighter, but it also has higher ratings for tension, compression and bending. All the rounded parts of the wings and tail surfaces are laminated, as are the fuselage stringers. The model was covered in Profilm (Oracover®). The trim and markings were hand cut from the same material. The wheels are from Dubro. Martin devised an interesting way of adding an arming plug to his model. He uses two pairs of 4-mm gold bullet connectors, soldered together into the arrangement shown in the accompanying photo. It forms an arming pin. This pin fits a corresponding pair of sockets in the RC-SF.COM
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COLUMN HOW TO
HELICOPTERS 101,PART 3
Learning to hover is like standing on top of a greasy basketball, while patting your head and rubbing your stomach. ~ anonymous
BY Dave Phelps
This is the Ares MD 500D CX 100, with its included transmitter—a nice looking little machine. The attention to scale detail is remarkable. The first version of the MD 500 was built by Hughes, fielded in Vietnam and was dubbed the OH 6 Cayuse LOH (Light Observation Helicopter). Known as the Loach by those who loved her, the angled horizontal stabilizer would cause a slow circular oscillation of the tail boom when it was hovered with a quartering tailwind. This little dance was affectionately termed the “Hughes Shuffle”.
S
o far, I’ve discussed basic aerodynamics and helicopter control systems. In this installment, I’m going to talk about some physics and then start putting it all together with a discussion about airflow. TOTAL FORCE No, this isn’t the title of the new Arnold Schwarzenegger movie; it’s a term helicopter pilots use to describe the entire output of the rotor system.
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Sir Isaac Newton’s second law states: the rate of change of the motion of a body is directly proportional to the applied force and inversely proportional to the body’s mass. Whew! What this means in American English is that motion is started, stopped or changed by causing the forces acting on the body to become unbalanced. The rate of change depends on the magnitude of the force and the mass of the body to which it is applied. Put it in language
even I can understand without burning a bearing, the harder you push, the faster it goes. This is the principle that provides the basis for all helicopter flight. Regardless of its orientation and direction of flight, total force is always perpendicular to the tip path plane. Total force is divided into two components: lift and thrust. Lift acts to counter gravity, thrust acts horizontally to accelerate or decelerate the helicopter in the
desired direction. The pilot controls the horizontal direction by changing the orientation of the tip path plane using cyclic pitch control, and total force by changing collective pitch and throttle, or power. WHEN LIFT IS MORE THAN JUST LIFT At a stable, no-wind hover, all of the opposing forces are in balance, so the helicopter remains stationary. The total force is acting only to oppose gravity. In order to make the helicopter move, a force must be applied to cause an unbalanced condition. The pilot moves the cyclic stick in the desired direction, in effect causing the rotor disk to trade some of its vertical lift for horizontal thrust. The result of this imbalance is that the helicopter starts to move in the direction of thrust. It also starts to descend because some of the total force previously used to counter gravity is now producing thrust. More total force is needed to balance out both gravity and the pilot-induced imbalance in horizontal forces described by Sir Isaac, so the pilot has to squeeze in a little more power or risk an unwanted aircraft-toground interface. As the helicopter continues to gain speed, more lift is traded for the thrust required to overcome the profile and parasitic drag of the airframe. If power is not increased
The box says, “An ultra-scale, ultra-stable indoor heli anyone can learn to fly anytime and anywhere!” Them’s some pretty tall words, partner. To put it to the test, Ginny takes the controls in the middle of our not-so-big shop. As you can see, Ares isn’t just blowing smoke. Ginny’s pretty good with a torch, but she doesn’t do video games. She can hover the MD 500D though.
as speed increases throughout the entire speed range of the helicopter, the aircraft will begin to descend. Similarly, if the weight of the aircraft changes, as in a turn, and power is not increased, speed will decrease as thrust is traded back for lift. The
This little bird is the Helimax Novus FP N200. It’s a very nicely designed, constructed and packaged micro helicopter. Charge the battery with the kit’s included charger, put some AA batteries in the transmitter, take her out to the driveway and she’s ready to go.
Marty on the other hand, is a video gamer. Like a duck to water, with less than half a charge under his belt, he’s already doing pirouettes and dodging the ceiling fan. He’s having a really good time too. I may have to take this thing home. No telling how much it’s going to cost me in lost wages if these guys have access to it when I’m not around. I know what it cost to make this photo shoot, and it’s kinda scary if I think about it too hard. I may have to go flying tomorrow to help me recover. Note to self—don’t forget the Loach… don’t forget the Loach… don’t forget the Loach.
balance between profile drag and thrust has been changed as the lift requirement increased. This is easily demonstrated by flying a racetrack circuit with a helicopter in forward flight using only the right stick, like you can with an airplane. At a moderate forward speed, the pilot applies left cyclic to start the turn and then pulls aft slightly to add lift to overcome the G force without losing altitude. It is possible, even likely that the helicopter will be flying backwards at about the time it seems it should be rolling out of the first turn. Unlike an airplane, which also slows in a turn—but still has its forward thrust delivered in the same direction in reference to the airframe independent of attitude and wing loading—a helicopter derives its forward thrust solely from its source of lift. In a turn, the cyclic must remain forward to keep the forward thrust RC-SF.COM
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COLUMN HOW TO
THE PEOPLES’ DRONE
NOW ANYONE CAN OWN AND FLY A SMALL UNMANNED AIRCRAFT SYSTEM With the release of the Phantom 2 Vision, DJI has put a fully functional Small Unmanned Aircraft System (SUAS) within reach of anyone who has $1,200 and a smart phone... But how does it work — and what does it mean? 56
RC SPORT FLYER . FEBRUARY 2014
BY Patrick Sherman
A look under the hood of the Phantom 2 Vision reveals the latest version of DJI’s hobby-level multirotor flight control system: a NAZA V2 equipped with a GPS receiver, to allow functions such as Return-To-Home and Intelligent Orientation Control.
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he DJI Phantom 2 Vision is, in my estimation, one of those products to define an era. When we look back on the development of multirotor and First-Person View (FPV) flying, we will use the release of the Vision as a historical landmark. Whatever else happens or has happened, it will all take place either before, or after, the Vision was launched. Now, you don’t have to be an especially skeptical reader to recognize that’s a huge claim I’m making, and to perhaps expect a little bit in the way of justification before you decide that you agree with me. Fair enough—there are two factors that have drawn me inexorably to this conclusion. First, DJI has deployed all of its considerable resources to make
the Vision easy to use—not just by current RC pilots, but by anybody. With the exception of a few tiny missteps, they have succeeded in creating an extremely capable aircraft with built-in FPV capabilities that a novice could reasonably be expected to pick up and fly right out of the box. Here at the Roswell Flight Test Crew, we do suggest starting with a high-quality simulator and a docile palm-sized co-axial helicopter—we’re looking at you, Blade mCX2—before you try slipping the surly bonds of Earth with your $1,200 machine. However, if you are steadfastly determined to teach yourself to fly on a full-sized bird, the Vision is probably about your best choice. The second reason I think the
Vision is destined to be enshrined in RC history is more profound and more likely to be overlooked. DJI isn’t trying to sell it to you, or me, or anyone else who understands what the Bernoulli Principle is and why it’s relevant to heavier-than-air flight. You see, the Vision isn’t an RC model—it’s a lifestyle accessory, a consumer product, a means to impress your friends on Facebook. DJI’s marketing video for the Vision makes this explicit, showing a bouncy, bikini-wearing blonde collecting her Vision before she heads out for a day at the lake with her strikingly handsome and wellgroomed group of friends. While they frolic and splash, the narrator tells us, “It quickly becomes part of something that you always think to take with you... Not only is it a RC-SF.COM
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REVIEW HOW TO
LAMINAR THE NAME SAYS IT—THE FIRST GLIDER TO USE A LAMINAR AIRFOIL BY Gene Cope
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esigned and built in the Czech Republic by Rudý Letov, the XLF-207 Laminar was a follow-on to the well-known 1950s Lunak LF-107 aerobatic glider. What made the XLF-207 Laminar unique for its time, was that it was the first European sailplane built using revolutionary laminar airfoil design for its wing sections. The Laminar’s first flight was made in August 1951, in the city of Letnany, in the Czech Republic. The glider was simply a modification of the Lunak, but was fitted with a laminar flow wing, which made it a
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standout performer for its day. What attracted me to the Esprit Model’s version of the glider was its unique design, the fact that the fuselage was composite, the wings were made of foam sheeted in wood and that it was quite affordable, which matters to someone on a budget. Also, I had ordered from Esprit Models previously, and I found their customer service to be very good, including safe, secure and fast shipping. So, it was pretty easy for me to make the decision to buy a XLF-207 Laminar from Esprit. Then too, Reichard Model Sport
recaptures the historic design lines and the nostalgia of the Laminar in their 4.4-meter wingspan version. The model is very well built and finished, including the wings being factory built and covered. The horizontal stabilizer and rudder are built and covered. Also, the fuselage comes painted, with a canopy frame and vacuum-formed canopy. Reichard provides a good hardware package as well. Suffice it to say, this is quite a good almost-ready-to-fly glider package. My XLF-207 Laminar glider was shipped via UPS from Esprit. It came
packaged well in a large box. All components—wing, stabilizers, rudder, canopy— were covered in bubble wrap to protect them against damage. Consequently, when I opened the model’s kit box, to photograph the parts for this review, I found all the parts and pieces in perfect condition. This glider was designed for slope soaring, winch launching and especially aerotowing. You’ll be interested to know the model uses a wing that has molded fiberglass leading edges, which will reduce the chance of damage
during takeoffs and landings. Its 4.4-meter wingspan wing uses the HQ 3.0/13 and HQ 3.0-10 airfoils sections (3 percent camber, 13 percent thick and 10 percent thick respectively). The wing’s doubletapered planform in combination with the Helmut Quabeck airfoils make for a fantastic flight platform. Note that the Laminar’s wings have split ailerons, a flap and a double-gate spoiler. The fuselage is a molded, epoxy impregnated composite construction. The overall construction techniques make for a very lightweight airframe.
FEATURES • Almost ready to fly • Fiberglass, composite fuselage • Foam wings sheeted in wood • Two-piece wing w/ steel joiner • Foam sheeted elevators • Main landing wheel • Elevator & rudder pushrods • Double-gate spoilers • Hardware package NEEDED • Transmitter - Jeti DS16 used • Receiver - Jeti Duplex R14 • Servos - Hitec (4) HS5085MG, (3) HS-5485HB, (2) HS-125MG, (2) RC-SF.COM
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REVIEW HOW TO
HADRON YOU’LL GO TO EXTREMES FLYING THIS WING! BY Wil Byers
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o you want to be a rock star? Buy this model and you’ll have all eyes on you at the RC airfield, or even when flying it at the slope. This is one crazy, wild, fun and exciting delta wing model to fly. I’m one hundred percent confident you’ll discover your rock star side when flying the Hadron. It is that much fun to fly. Seriously, the new Flyzone Hadron delta wing is a foam airplane,
Just hit the “gas” to have a gas with this crazy and wild flying Flyzone Hadron delta wing, with its thrust vectoring system.
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that is transmitter ready (Tx-R) right out of the box. It comes with a brushless motor fitted to a thrust vectoring system, which gives the model maneuverability nearly unheard of for other models. The electronics come factory installed as do the servos, control rods, etc. What caught my eye about the Hadron is you need not do much of anything to get it assembled and ready for flight. Also, it is designed
to link with a Tactic® 6-channel 2.4-GHz transmitter. It comes with everything already installed. You simply bind transmitter to receiver and the airplane is ready to fly. I also saw it as a model I could take slope soaring as a way to get some added excitement, and to make certain I would not be walking to the bottom of the hill for a retrieval if the wind should die. Then too, the Hadron is an
Everything you need to fly comes in the Hadron’s transmitter-ready (Tx-R) version. You only need a Tactic transmitter to get it flying.
unusual model in that it is a flying wing, with elevons for pitch and roll control. Throw in the fact the model is a pusher type model, with the motor mounted in a thrust vectoring system (left and right), and you have a model that caught my attention. I also like its striking color scheme, which I think makes it easy to see in the air. If you are like me and don’t have much time to just grab a model and go flying, this airplane will appeal to you too. Additionally, consider it is an electric-powered model and you’ll recognize that you can throw it in the back of the Rolls-Royce Ghost
without worry of staining the leather. Alternately, you can fly this model at the park down the street.
NEEDED TO COMPLETE • Tactic TTX650 6-channel transmitter
FEATURES • 2200 Kv brushless motor • 40-amp brushless ESC • Three mini, one high-torque mini servos • Tactic® TR624 6-channel 2.4-GHz SLT receiver • ElectriFly 11.1-volt 2200-mAh LiPo battery • ElectriFly DC LiPo balancing charger • Two electric propellers
OPTIONS • ElectriFly 14.8-volt 2200-mAh 30C LiPo • ElectriFly Triton EQ charger/ discharger/cycler
The Hadron is very responsive to control input, and will absolutely roll like a top at full control throws—lots of fun!
IN FLIGHT It was 17 degrees the day I test flew the Hadron at Kiona Butte. Even so the sun was shining bright and there was about a five mile per hour breeze blowing straight into the face of the butte.
The bottom view of the model gives you a good look at how the ailerons’ servos are installed as well as the thrust-vectoring motor. RC-SF.COM
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REVIEW HOW TO
SEVEN MILLISECONDS AWAY FROM PURE PERFECTION
BY Staff
The new Aurora 9X looks almost identical to the original Aurora 9, however, the upgrades to this new system are significant, including its new seven-millisecond frame rate.
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On the top right side of the transmitter are two threeposition switches, one two-position and one snap switch. There is a slider and the RT trimmer also.
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itec’s RCD’s introduction of the Aurora 9 2.4-GHz radio system a couple of years ago made a huge leap forward in an easy-to-program user interface and radio frequency system. Their new Aurora 9X moves 143 steps closer to
On the top left, there are three three-position switches and a two-position switch, plus the slider. The LT and CT trimmers are just to the right of switch A.
radio control perfection! Using Adaptive Frequency Hopping Spread Spectrum (AFHSS) technology, Hitec’s Aurora 9X transmitter system has implemented new features that make it a standout in the RC industry. This is especially
The control stick gimbals are ultra smooth. The sticks have adjustable lengths and tensions. You adjust the tensions via screws that are accessible through the case’s back.
so when you consider the price is only $509.99 at towerhobbies.com, including an Optima 9-channel receiver. The new Aurora 9X is designed to provide programming features and functions for RC airplanes,
The Aurora 9x offers six control modes. They are 1, 2, 3, 4 and Manual 1 and Manual 2. You will access the control modes through the radio System settings.
RC-SF.COM
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REVIEW HOW TO
EXTRA 330SC BP 3D
GETTING BACK TO BASIC 3D FUN AND EXCITEMENT BY Staff
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ooking at the E-flite Extra 330SC BP 3D airplane is reminiscent of the early days of electric-powered airplanes—a time when a four-minute flight was something to brag about, and hovering a model was a sign of pilot skill. Today, hovering an airplane is commonplace and four-minute flights are certainly nothing to brag about to onlookers. The new E-flite Extra 330SC BP 3D almost-ready-to-fly (ARF) airplane is a state-of-the art version of the early RC profile airplanes that
made electric-powered 3D airplanes popular. It sports an ultra-lightweight wing that is made of balsa ribs covered in UltraCote® Lite material. The ailerons are large control surfaces that give the model an extremely fast roll rate. The rudder is huge too, so you can knife-edge this little airplane without much trouble. Additionally, the stabilizer and elevator are generously sized such that the pilot gets plenty of pitch control, which aids in maintaining those long hovering flights. This model has the Extra 330
The kit components are the typical high quality E-flite parts. You get the airframe and parts, plus a well-written and documented manual.
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profile, with a pilot head filling the cockpit. The see-through wing is covered in bright red, yellow and blue, so the model is easy to see in the air. The model even includes a landing gear, with foam wheels and wheel pants. This little model sports the power of a modern-day E-flite 450 outrunner motor that is married to a 30-amp ESC and a 3S 1350-mAh LiPo battery pack. It uses affordable radio control gear including a Spektrum® AR610 receiver and E-flite DS76 digital throughout. All around, this is a very attractive model!
These are the components you must buy to complete the Extra: motor, ESC, battery, receiver, servos, and extensions.
You will like how much power the E-flite 450 outrunner motor provides, which will let you hang it on its propeller for some hovering around fun!
As you can see, the APC 12x6e propeller provides plenty of prop blast over the wing and elevator to give the model super 3D authority. RC-SF.COM
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