Electric ducted-fan jets

Model Airplane News, Dec 2000

A new generation of sport and high-performance models is here!

A renaissance is occurring in electric flight, and one of the several rapidly expanding segments is that of electric ducted-fan (EDF) aircraft. Whether you are an intermediate-level flier or a hot-dogger who's looking for a high-performance jet that will go 75mph or faster in "stock" configuration, there is an EDF plane for you. In short, a newand surprisingly diverse-world of EDF aircraft and fan units is now available. Electric jets, which traditionally have been smaller models, are growing in size. Electric-powered fans with inside diameters of up to 5 inches are becoming available, and multi-fan EDF models are available with wingspans greater than 6 feet.

Our chart sampling EDF aircraft sold in the U.S. (if you have access to the Web, visit the noted websites!) represents only a cross-section of available products. The cited airplanes illustrate the surprising variety available in the EDF category, and more are coming soon.

If you are just getting started in EDF airplanes, Kyosho* has three great models to choose from: a T-33, an F-16 and a twin-fan Learjet. They are affordably priced and offer good handling characteristics for intermediatelevel pilots who wish to explore the emerging world of electric jets. Distributed by Great Planes* and widely available in hobby shops, these aircraft have helped propel the EDF craze forward.

THE HISTORY

The history of EDF starts with glow power. In the 1950s, Berkeley Models sold a line of glow-powered ducted-fan models that used stamped-aluminum, 6-blade rotors. On the other side of the pond, the English also pioneered the Veron glow-powered fans. By the early '90s, the Morley EDF had arrived from the U.K. It was a 10-blade fan that was powered by "RC car" motors. The Britishdesigned Electro Jet fan came soon after and was one of the first really flyable fans that showed improved efficiency.

Electro Jet was eventually bought out by Oliver Wennmacher, who currently produces the very successful WeMoTec fans. Meantime, in the U.S., Kress Jets* had produced the RK series of electric fans, and these and other electric fan lineages continue to evolve.

In recent years, demand for new fan/motor combinations and new model airframes has grown worldwide, and the results are impressive.

THE FUTURE

Not only are inexpensive electric motors becoming more powerful, but a new generation of brushless motors also promises lower cost and high performance. Where will these developments take the hobby? On the one hand, it appears that the ever more efficient fan units being brought to market may offer new possibilities for small glow applications. On the other hand, high-performance EDF aircraft are now flying at speeds greater than 100mph. Electrics will always have the advantages of clean, quiet power and ease of operation. Will the weight and duration penalty of batteries be mitigated by fuel cells or new Ni-Cd, NM-HY or lithium cells? Time will tell. What is certain is the continued, rapid evolution of EDF technology.

Companies of Note

Bill Griggs Models

Bill Griggs provides a starting point for the modeler who wants to buy an affordable kit or an entry-level trainer. His "Screamer," a Don Belfort design, is ideally suited for flying in large, park-like open spaces. See also his BD-10 and Panther designs at http://www.aiusa.com/bgriggs/.

Electric Aero Modeling USA

EAM has an impressive product selection, to say the least. We counted 21 EDF aircraft in EAM's online catalog, nine planes in development (don't miss their "Skunkworks" Web page! An XB-70 EDF?!) and various semikits (still to be priced as we went to press). Owner Dave Roberts noted that EAM's goal was to offer a wider range of quality EDF products than any other source, and EAM's website appears to fulfill this goal; see http:/.eam.net. Dave was quick to point out his laser-cutting, CNC-foam cutting and moldedglass resources, which are targeted at further expanding his product line.

Electric Jet Factory

The Electric Jet Factory focuses on researching "next steps" in EDF materials and technology. Pushing forward with all-composite designs that are equipped with landing gear for ROG takeoffs (see the MiG-15, Mini A-10 and Rafale designs), the company is working hard to build a "high-performance" reputation. Kress Jets and the Electric Jet Factory have announced plans to pursue new fan configurations that will further raise the bar. See www.ElectricJetFactory.com for more information and video clips of aircraft in flight. Owner Robert Wagoner is a member of the American Institute of Aeronautics and Astronautics (AIAA) and has been involved in ducted-fan and airframe projects ranging from wind-tunnel flow analysis to experimental NASA-related test aircraft.

K&A Models

Owner Ken Williams noted that K&A's approach is to provide aircraft that can be equipped for sport flying (e.g., 45mph) or high-performance EDF flying (75mph plus). Skewing slightly from pure scale to enhance flight characteristics, K&A offers an L-39 Albatros and a MiG-15 (among other products). As Ken put it, "How advanced you go is just a matter of your comfort level." Check out http://www.kamodels.com/kitindex.htm. Models to watch for from K&A include an Me 262 and an F-84.