Written by Jon Barnes
Add A Touch Of Color To Your EDF Jet Experience
As seen in the July 2021 issue of Model Aviation.
Review
Access additional content by visiting www.ModelAviation.com/bonuscontent.
WATCH A VIDEO ONLINE!
Access additional content by visiting www.ModelAviation.com/bonuscontent. THE HAWKER HUNTER, developed in the late 1940s to early 1950s, was the first jet-powered aircraft to be produced by the British manufacturer Hawker Aircraft Limited. Alhough it was originally designed to fulfill a jet fighter role, a diverse number of Hunter variants were developed throughout its impressively lengthy 60-plus years of active service, resulting in it also being used in fighter-bomber, aerial reconnaissance, and training roles. Although a few manufacturers in the RC industry have, in the preceding decades, released foam-composition, EDF-powered models of this jet, they have all since slipped into oblivion and obsolescence. EDF jet pilots who are hungry in 2021 for a Hunter will definitely delight in Dynam’s decision to produce and release a 70mm EDF-powered, EPO foam-composition model of this venerable British aircraft. Dynam’s 70mm EPO foam-composition Hunter comes bedecked in an accurate, scale yellow and black camouflage scheme. It appears to be modeled after a full-scale Hunter that was originally in service with the Swiss Air Force in 1957. That particular aircraft was then repurchased by Hawker Siddeley in the 1970s and became one of eight aircraft to be refurbished into the TMk68 variants. Acquired by the Hunter Flying Group in 2001, the current home of the J-4206 Hunter (HB-RVV) is apparently the Fliegermuseum aviation museum in Altenrhein, Switzerland. (This museum appears to have three different Hunters.) The museum’s website even claims that it is possible to book a flight in a Hunter, although no available calendar dates appeared when I clicked on the "Book a Flight" button. This model includes retractable tricycle gear, plastic-composition split flaps, wingtip-mounted navigation lights, a selection of removable foam underwing armament, and a 12-blade, 70mm brushless EDF power system. Eight 9-gram-class servos are preinstalled in the airframe and are used to control all flight surfaces and the nosewheel steering. Completion of the Hunter requires a minimum six-channel radio system and a 6S 3,200 mAh LiPo battery with a suggested minimum discharge rating of 30C.Assembly
Assembly instructions, in the form of a single, black and white fold-out sheet, are included in the box. A single-sheet user manual/programming guide is also included for the Skylord 80-amp ESC. Pilots are guided through the assembly of the Hunter by means of a series of eight small photographs. A single carbon-fiber spar is used to reinforce the wing, with a smaller-diameter spar doing the same for the horizontal stabilizer. The wing halves attach to the fuselage using fasteners. The twin horizontal stabilizer/elevator halves (each equipped with its own 9-gram servo) are designed to be permanently glued in place. Dynam includes a small tube of contact cement in the box. For best adhesion, builders will want to remove the paint from the roots of both stabilizers and the corresponding points of attachment on the vertical stabilizer. I like to poke a plethora of small holes in both of the mating surfaces using a bamboo skewer or toothpick. This gives the adhesive a place to flow when the surfaces are pressed together and makes for a better bite. Pilots should also slather some adhesive on the stabilizer spar when inserting it in place. Connections for the elevator servos are made up in a rectangular cutout, located at the base of the vertical stabilizer. Access is gained by removing four tiny screws, which releases the opposing plastic covers. Also nestled inside of this cavity is an unanchored 24-gram slug of lead. (I repositioned it in the forward part of the battery bay in order to help achieve the center of gravity [CG] that is recommended in the assembly guide.) The included adhesive-backed graphics can be applied to the Hunter using the black and white placement guide, also located on the assembly sheet. Because of its relatively small size and lack of color, my 50-something eyesight found it difficult to effectively use this graphics placement guide. Using the ever-available abundance of online aircraft resources, I was able to find and use a few larger, color photographs of the full-scale aircraft for reference in this final assembly task. The included foam-composition underwing armaments were placeed using plastic T-shaped retainers. The assembly guide provides pilots with a recommended range of control throws for each of the primary flight surfaces. I set up triple rates, using the lower numbers for low rates, the higher numbers for mid rates, and then full mechanical throws for high rates.Flying
An XT60 connector (rated for 60 amps) comes factory attached to the 80-amp ESC’s power leads. The 6S batteries that are typically used by pilots flying 70mm, 80mm, or 90mm EDF-powered models utilize connectors with higher current ratings (EC5, XT90, etc.). Pilots will need to either source the required adaptor or replace the XT60 with a connector of his or her choice. I decided to trust the manufacturer’s choice of connector and used an EC5 to XT60 adaptor. (This is not the first 70mm 6S-powered jet that I have reviewed that uses an XT60 connector.) Getting the recommended 6S 3,200 mAh battery nestled in place under the canopy requires a bit more strategy than many jets. The battery bay is slightly cramped side-space-wise. Pilots who are interested in upsizing their flight battery to a larger-capacity pack to extend flight durations or to shift the CG so that the Hunter is slightly nose-heavy will need to perform some creative enlarging of the battery bay. The factory-installed battery hook-and-loop retention strap was barely long enough to reach entirely around either of the two 3,200 to 3,300 mAh packs that I used. I decided to supplement this strap with a bit of surface-mount hook-and-loop material applied to the wooden battery tray. With the recommended battery pack in place, I could not achieve the factory-recommended CG range of 140mm to 145mm, measured from the leading edge of the swept wing at the point where it intersects the fuselage. I carved out a small recess in the foam deck ahead of the battery bay and glued in the 24-gram weight that I removed from the aft end of the airframe to help get the model closer to the recommended CG range. On the takeoff roll of the second flight, I was about to initiate rotation when I heard a loud, shrill "zinnnnngg," and saw a small amount of debris ejected rearward out of the Hunter’s exhaust. Upon inspection, I was surprised to see that all 12 blades of the impeller and spinner were gone! Although I have never experienced foreign-object damage (FOD) from the club runway in my many years of flying EDFpowered jets there, I theorize that something was pulled into the fan through one of the two square-shaped auxiliary air intakes that are located on the underside of the model. Although many of the EDF-powered models that I have owned throughout the years utilize plastic guards/grates that are designed to help prevent loose objects from being sucked up and into the fan, this model foregoes any such FOD-limiting devices. I reached out to Bitgo Hobby’s customer service and the staff quickly and efficiently dispatched the parts required that made my model airworthy again. With repairs made, I returned to flight-testing. This model’s widely spaced tricycle landing gear made for great handling on the ground and terrific tracking in the takeoff roll. Dynam did, however, take noticeable liberties with the excessive length of the gear struts, as compared with those of the full-scale jet. Pilots who place a premium on a model possessing an accurate and scale profile/appearance might wonder why Dynam went with the long, storklike struts. With the model in the air and the gear retracted, this aircraft quickly morphs into one that creates a pleasing, scalelike appearance. Thanks to the notable trustworthiness of the powerful 70mm brushless power system, the Hunter takes to the air with impressive haste. I determined early on in my flight-testing that I preferred high-rate elevators and medium- to low-rate ailerons. The Hunter’s outboard ailerons are quite effective and give this model a rapid roll rate. The smallish elevators are not, however, as effective at creating changes in the pitch axis. With the Hunter trimmed out, I especially enjoyed carving out large, sky-filling loops. The impressive amount of thrust created by the Dynam 70mm EDF power system allows pilots to tear up the sky with nearly any combination of basic aerobatic maneuvers. I did notice a bit of wing flex when pushing the Hunter hard in the corners and when executing abrupt changes in direction. The bright yellow camouflage top side and solid-colored, light gray underside offer pilots bulletproof in-flight orientation cues. Pilots who enjoy flying jets with longer flight durations will be pleased to find that the Hunter can squeeze flight durations of 5 to 6 minutes (or possibly beyond) out of a 6S 3,200 mAh battery.Conclusion
As a 70mm EDF-powered foam jet, the Dynam Hawker Hunter offers EDF pilots who are on a budget an affordable, lesser-modeled aircraft that can impressively squeeze 5 to 6 minutes of flight duration from a 6S 3,200 to 3,300 mAh LiPo pack. Smaller 64mm EDF-powered jets often lack the flaps and retractable gear that this Hunter includes. Larger 80mm to 90mm EDF-powered models are typically much more expensive and require larger and more costly 4,500 to 5,500 mAh batteries, with typically much shorter flight durations. Although the scale outline of this Hunter takes liberties in several areas, it nonetheless offers jet pilots who simply focus on having fun with their models an enjoyable and satisfying break from the more commonly modeled modern fighter jets.SOURCES:
Fliegermuseum Altenrhein Altenrhein, Switzerland www.fliegermuseum.ch/flotteDynam Hawker Hunter 70MM EDF Jet