RC Ducted Fan Jets

"RC ducted fan jets are the most common
type of radio conrolled jets!"

There are also pusher RC jets which simply have a pusher propeller at the rear of the aircraft. Gas turbine RC jets have real turbine engines just like full scale jets. This page describes the different types of RC ducted fans.

Ducted air fans consist of a fan inside of a tube. The fan can be powered by either an electric motor or a glow engine. RC electric ducted fan jets are referred to as EDF RC Jets. Glow powered ducted fan jets are referred to as GDF RC jets (Glow Ducted Fans).

The tube prevents losses in thrust from the tips of the fan blades. This greatly increases the efficiency of RC ducted fans compared with conventional propellers.

RC ducted fans have shorter and more blades than conventional propellers. This allows them to run at much higher speeds.

Huge Selection of Ducted Fan Jets on eBay!

RC Ducted Fan Jets for Beginners

The "tube" of most RC ducted fans is the aircraft itself. As a matter of fact, all GDF's that I am aware of have internal ducted fans. Some EDF's have ducted fan units mounted under the wings or near the rear of the fuselage.

Other's have internal ducted fans. Take a look at the Megatech A7 Tornado RTF Jet ducted fan jet shown to the right, which has an internal ducted fan. The fan pulls air into the front of the fuselage and pushes it out of the rear, much like a full scale just.

Are you ready to try your hand at flying an RC ducted fan jet? If so, the Megatech A7 Tornado RTF Jet is the perfect choice for your first RC jet. It's ready to fly straight out of the box. It is constructed of super strong PolyNylolene foam. It comes with a NiMH rechargeable battery and charger. You can't beat that for the low price of this RC fighter jet!

Hobbico Flyzone Diablo EDF Jet Trainer RTF

Hobbico's Diabolo (EDF) RC Ducted Fan Jet Trainer is another excellent aircraft for learning to fly RC Jets. The Diabolo is significantly larger and flies faster than the A7 Tornado. A Hyper Flow RC Ducted Fan System like the one at the top of this page is installed in Hobbico's Diabolo.

Both of these electric RC ducted fan jets are designed specifically for beginner jet pilots. Keep in mind that these jets, especially the Diabolo, are not suitable for pilots without prior RC flying experience. You need to have mastered a basic trainer airplane or beginner park flyer before attempting to fly an RC jet.

Electric RC Ducted Fan Jets (EDF)

To understand the role of each component of an electric RC ducted fan jet, lets take a look at the image to the left. This is an image of GreatPlane's Hyper Flow RC Ducted Fan Jet System.

Rotor Cone & Front Housing Flange:
The rotor cone and housing flange keep the airflow laminar, or smooth, as it enters the fan. This increases the efficiency of the ducted fan unit.

Fan Rotor:
The rotation of the fan rotor, or impeller, is what drives the air through the unit.

Housing:
The ducted fan housing is what contains and directs the airflow. The profile or shape of this housing is critical to the efficiency of the ducted fan.

Motor:
The motor is what provides the torque to turn the fan rotor.

Aft Cone:
The aft cone reduces or eliminates turbulence caused by the air passing over the motor or engine.

Stator:
When a fan is housed in a shroud, the rotation of the fan blades will cause the air to move radially as well as axially. In other words, the air will begin to flow in a vortex like a tornado. This rotation of the air would cause turbulence which would reduce the efficiency of the ducted air unit. Stators are stationary fan blades inside the housing that straighten the air the air flow as it passes.

Glow Powered RC Ducted Fan Jets (GDF)

Glow ducted fans use glow engines specifically designed for driving a ducted fan. The image to the right is an OS .46 VX-DF with a mac's tuned pipe used in conjunction with a Turbax 46 fan unit. The Turbax fan unit can be found at Jet Hangar Hobbies.

More examples of different types of tuned-pipes can be seen below. As you can see, tuned pipes are used with land vehicles as well.

A tuned pipe is needed when using a glow engine with a ducted fan. The tuned pipe is that long tube you see extending from the engine. A tuned pipe basically pushes unused fuel from the exhaust back into the engine to increase the power. The tuned pipe must be "tuned" to the maximum RPM by adjusting its length. O.S has a great page explaining what tuned pipes are and how do they work.

Glow engines designed for ducted fans are made a little differently. Take a look at the OS .46 VX-DF engine to the left. Notice how the carburetor is in the rear of the engine instead of being in the front. Notice how the exhaust is also in the rear. The carburetor is moved to make room for the front of the engine to fit into the fan duct. The exhaust port is in the back so the tuned pipe can run straight back so that the entire GDF unit will fit nicely inside the fuselage.

Most Common GDF Manufacturers

Dynamax Fan -can be found at Jet Model Products

Turbax fan - can be found at Jet Hangar Hobbies.

Ramtech Fan

Bob Violett's Viofan

Jethangar Hobbies has a wealth of information pertaining to RC ducted fan jets. This page is loaded with information on glow ducted fans, electric ducted fans, and turbines. It's an excellent site to explore for information on RC model jet airplanes.

Examples of GDF Installations

The image to the left is a Balsa USA Enforcer (GDF) RC ducted fan jet with an O.S. 91 DF large head glow engine used in conjunction with a Byro-jet fan package. Notice how the engine faces the rear of the jet. This is a called a pusher fan set-up. Most ducted fans are tractor fans, meaning the engine faces the front of the plane and pulls the are over the engine. Tractor fans are more efficient because the suction end of the fan is not restricted by the engine. Tractor fans also do a better job of cooling the engine since all the air is pulled across the engine. But as you can see, pusher fans are also very common.

Don't confuse an RC ducted fan jet with a pusher fan with an RC pusher jet. An RC pusher type jet has a convententional pusher propeller with no tube.

To the right is a close up of this ducted fan installation. This fan is mounted on top of the aircraft with its own tube as opposed to being housed inside the fuselage.