On a 2008 winter morning, a full-size EZYCOPTER built with a YOSHINE CDS-II was started for tests.



With increased interest in personal vertical lift concept and customized development of personal helicopters, YOSHINE has been offering CDS kits to people who want to build their own coaxial helicopters. 

As the CDS-II technology has become more mature with more available options, we can offer parts, kits, or fully assembled CDS-II. A CDS-II can be mounted on top of a helicopter frame of a proper design with no tail rotor.

Building a coaxial Vertical Lift machine may be more affordable that ever before with a YOSHINE CDS-II.  Here is an animated video showing how an average CDS is constructed:


YOSHINE EZYCOPTER II Preliminary Specifications

(Specifications are subject to changes without notice due frequent improvements.)


Single and twin-seat coaxial helicopters, kit built, based on proprietary YOSHINE Coaxial Drive Systems (CDS).


As of December, 2008 a two-seated EZYCOPTER-II demonstrator had been tested and refined for production. As of March, 2009, two types of Coaxial Drive Systems (CDS) CDS-I and CDS-II have been delivered to experimenters and developers of coaxial helicopters in more than five countries in 3 continents.

Kit Costs

Complete EZYCOPTER II kit will include CDS-II kit, twin engines, four rotor blades, and a composite airframe. Buyer can also supply own engine, airframe, and control linkage.  Prices upon request.

Design Features

EZYCOPTER II employs the proprietary YX-24 Coaxial Drive System (CDS) No-Tail-Rotor technology with individually suspended and articulated coaxial rotor system. Twin engines and four rotor blades will be included. EZYCOPTER II is designed to meet the FAA 51% regulation to be certified under FAA FAR Part 21.191 as a home-built coaxial helicopter.

Distinctive features of the EZYCOPTER:

Flight Controls

Integrated 3-in-1cyclic, collective, and yaw controls.

Airframe Structure

To be constructed with metals (chrome-moly and aluminum) and composite materials (carbon and glass fibers).

Landing Gear

Twin-skid type.

Power Plant

Offered choices of following options: 

(1) Two 60hp Hirth two-cylinder forced air-cooled two-stroke low rpm high torque engines, or

(2) Two 45hp RX-50 single rotor water-cooled rotary engines.

(3) Rotax 912 or 914 engines

(4) Lycoming or Continental (100hp~120hp)

Dimensions, External

  • Rotor Diameter        6.00m (19' 7”)

  • Fuselage                3.90m (12' 8”)

  • Height                   2.60m (8' 5”)

  • Skid Track              1.80m (5' 9”)

Rotor Disc Areas

28.27 m(304 sq.ft)

Weights and Loadings

Weight empty            280 kgs (617 lbs.) approx.


                                1) CDS-II                                   = 93 kgs.*

                                2) Rotor blades (8 kgs x 4)            = 32 kgs.

                                3) Hirth engines (31 kgs x 2)          = 62 kgs.

                                    (RX-50 engines = 25 kgs x 2 = 50 kgs.)

                                4) Airframe (Fuselage)                  = 80 kgs.**estimate

                                                                      Estimate Total   = 267 kgs (588 lbs.) 

Payload                   200 kgs (440 lbs.) approx.




Price for a CDS-II kit will be provided upon request. You will need to build an airframe with a conventional helicopter control linkable package for cyclic, collective, and foot pedals for yaw control.

An engine (or twin engines) from 80hp up to 120hp to drive the CDS is also needed - either two-cycle, four-cycle, rotary, or turbine. We offer either Hirth 3202 2 cycle or RX-50 rotary engines.

CDS-II kit will come with all parts shown below, four aluminum rotor blades, and more. (Request for a copy of CDS-II Parts List.)