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GEMINI CH 620 - Your Personal Twin-Engine Kit Aircraft

Prototype Aircraft Development Update

The Gemini CH 620 project is still under development and kits are not available.
AVAILABILITY TO BE ANNOUNCED UPON COMPLETION OF DEVELOPMENT PROGRAM

Continuing Prototype Development:

  • While we are expecting to complete the Gemini project, the status of the project is currently on hold. Quite frankly, we're just too busy currently and do not have the time to devote to complete the project.

Designer Chris Heintz stated he is continuing development of the Gemini CH 620 twin-engine kit aircraft design, and is experimenting and refining design aspects on the concept aircraft introduced in 1996. Among targeted development plans, Heintz is experimenting with a new wing airfoil that promises to be better suited for the twin-engine configuration of the Gemini - for better performance and flight characteristics, and other engine / prop choices. While the Gemini project is moving forward, it is currently not a priority item for designer Chris Heintz and kits are not expected to become available for several more years.

For information on our other kit aircraft designs, check out the Zenith Aircraft Homepage at http://www.zenithair.com


  • February, 1998:
    Designer Chris Heintz stated he is continuing development of the Gemini CH 620 twin-engine kit aircraft design, and is experimenting and refining design aspects on the concept aircraft introduced in 1996. Among targeted development plans, Heintz is experimenting with a new wing airfoil that promises to be better suited for the twin-engine configuration of the Gemini – for better performance and flight characteristics.

    "The concept prototype has proven the design to be very viable, and interest in the design has been higher than expected," Heintz said.  "However, the prototype has shown areas where the design can be improved and I don't want to release the design for production until we've experimented with a few more ideas."  Heintz stated that the kit for the personal twin-engine aircraft would not be available until further development: "Rather than being satisfied with a 'good' design, we're continuing developement of the prototype so that we can offer an 'excellent' twin-engine kit aircraft design."

Prototype Status (1998):

  • Final flight test phase of prototype concept aircraft (Midland, ON) - COMPLETE
  • First Flight Completed: July 23, 1996, (0820 central), Mexico, Missouri
  • FAA Airworthiness Certificate issued July 16, 1996 (Experimental R&D).
    Prototype: Serial No: 5-0001, Reg: N6265N
  • Basic IFR panel: Gyros (horizon, turn & bank, DG), Bendix/King KX-155 Nav/Com, KT76A Transponder w/ encoder, KI-208 Indicator.
  • Retractable landing gear system has been fixed open for initial flight test program.
  • Prototype was flown to the EAA Oshkosh convention (7/30/96) and Sun'n Fun (4/97).

Official Flight Test Program being conducted by Chris Heintz
(Flight test program of prototype concept aircraft).

Background: Since Oshkosh (August 7), we havn't released significant news on the GEMINI project. Though we've been swamped with inquiries (and deposits), we've been holding off providing specific performance until designer Chris Heintz had a chance to perform thorough flight evaluations and tests on the prototype GEMINI.

The prototype was delivered to Zenair Ltd. (Midland, Ontario) on August 30 in time for Zenair's annual Open House event on August 31 (which attracted more than 3,000 aviation enthusiasts).

Poor weather (flight testing requires good weather conditions to be meaningful) and other priorities (IFR and spin certification for the CH 2000, deliveries of trainers to India) delayed Heintz in resuming the Gemini flight test program until mid-September.

Initial Report From Chris Heintz (abbreviated):

From September 16 - 23, beautiful fall weather has yielded the following preliminary test results, with landing gear extended (down), full fuel (34 US Gal.) and one standard (170 lbs.) pilot:

  1. @ 75% power on both engines, Vn = 128 mph true (from SL to 5,000 ft.); 130 mph true at 7,000 ft. (standard atmosphere).
  2. Rate of Climb (both engines) at 75 mph is 1,600 FPM at SL
  3. Ceiling (both engines): Well over 12,000 ft. ASL
  4. Single Engine (the critical engine is the Left engine, which was shut down for the following):
    1. Rate of Climb at 3000 ft. is still 400 FPM (which equates to a ceiling of about 5,000 ft. at 1150 lbs.)
    2. Cruise speed (75%) on SE: 90 MPH.
    3. Stall speed is practically Vmc (minimum controllable speed) and is close to 55 MPH (though this isn't a very accurate figure yet).

From Here: Overall, the prototype is a real joy to fly with very good characteristics. It appears that very few changes will be required to the prototype. With retracted gear and new streamlined production cowls, I believe the Gemini will exceed forcasted performance figures. The Jabiru engines have been performing flawlessly to date. Assuming good weather ahead and no unforseen priorities, we'll continue with the flight test program during the coming weeks and we'll keep you up-to-date of results.

We found some good details and info on Jabiru engines:
Jabiru Factory (Australia)


GEMINI CH 620 Prototype Image Library
Air-to-Air photo (6/97) Air-to-Air photo (6/97)
Air-to-Air - view of the belly (6/97) Air-to-Air photo (6/97)
Chris Heintz flies prototype (9/23/96) It Flies!.. (7/23/96)
High Speed Fly-By (7/26/96) Pre-flight engine warmup... (7/25/96)
Taxiing out for first flight (7/23/96) Ready for take-off... (7/23/96)
Ready for landing... (7/23/96) Gemini Project: Ready for flight (7/16/96)
Running up the engines for the first time (7/16/96) Gemini Project: Ready for flight (7/16/96)
The plane's done, the crew's tired (7/17/96) Weighing in under 745 lb. (7/12/96)
Final systems installation (7/12/96) Canopy Installation (7/07/96)
Outboard Wing Assembly (6/30/96) Wing Fuel Tank (6/30/96)
Horizontal Tail Assembly (6/30/96) Rear Baggage Area (6/30/96)
Extended Gear / Wheel Well (6/30/96) Retracted Gear (6/30/96)
Cabin Area (6/21/96) Jabiru Engine Installation (6/21/96)
Front View on Gear (6/21/96) Center Wing Section & Spar (6/96)
Center Section with Gear / Engine Mount (5/96) Jabiru Engine Installation on Mount.
Jabiru Engine arrives (5/96) Fuselage Rear View (5/96)
Rear Fuselage Assembly (5/96)  

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Sport-Pilot Ready Kit Planes from Zenith Aircraft Company

 Zenith Aircraft Company

Zenith Aircraft Company
Mexico Memorial Airport, PO Box 650
Mexico, Missouri, 65265-0650 USA.
Tel: 573-581-9000 (Mon - Fri, 8-5 Central),
Fax: 573-581-0011
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Zenith Aircraft Company: 2008-01-02

 

GEMINI
Your Personal
Twin-Engine
Kit Aircraft

GEMINI CH 620