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About the Aircraft
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Onex Kits:
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The Bottom Line: What will my project cost?

Onex (pronounced “One-X”) is a single-seat aircraft designed to offer an even-more economical way to build and fly your sport pilot aircraft! The folding-wing design can fit into a garage, or share a T hangar with your flying buddies, be trailered on local roads, and the wing panels are easily removed for trailering at highway speeds. The Onex follows the Sonex Aircraft design and engineering tradition in offering a simple, robust, aerobatic aircraft capable of squeezing incredible performance out of lower powered engines.

Onex and AeroVee:
Made for One Another

Like all other Sonex Aircraft, the Onex is designed for use with the AeroConversions AeroVee Engine. Our simple, low cost, and technically advanced AeroVee Engine Kit is a perfect fit for the Onex, offering outstanding performance and economy.

Onex Specifications (updated 4/29/11)
16' 5" [5.00 m]
Wing Span:
20' [6.09 m] (Option for 18'9" [5.72 m])
Wing Area:
84.4 sq. ft. [7.84 sq. m] (Option for 78.0 sq. ft. [7.25 sq. m])
Tail Configuration:
Tail Height (Std Gear): 53"
Tail Height (Tri-Gear): 71"
Tail Width--with tail tips:
Total Width w/ Wings Folded:
(interior width required for enclosed trailer)
Main Gear Width: 62" (with wheel pants)
Air Foil:
Primary Structure:
6061 aluminum
Cockpit Width:
27 in.
Fuel Capacity:
15 US Gal. [56.8 Liters]
Stall Speed (full flaps):
45 mph [72.4 km/h]
Stall Speed (clean):
50 mph [80.5 km/h]
Max Flap Extended Speed (Vfe):
110 mph [177 km/h]
Maneuvering Speed:
151 mph [243 km/h]
Never Exceed Speed (Vne):
216 mph [349 km/h]
Performance 80 hp 2180 AeroVee

Empty Weight

600 lbs. [272.2 kg]
Range 535 miles
Cruise Speed @ Sea Level* (TAS) 135 mph
Cruise Speed @ 8000 ft (TAS) 155 mph
Power Loading (GW/HP) 11.875
T.O. Distance 400 ft
Landing Distance 500 ft
Service Ceiling (calculated) 16,000 ft
Aerobatic Category 80 hp 2180 AeroVee
Gross Weight 950 lbs [430.9 kg]
Baggage (Max) 20 lbs
Useful Load 350 lbs
Rate of Climb 700-900 fpm
Positive Load Factor +6.0 Gs
Negative Load Factor -3.0 Gs
L/D 10:1
CG Limits 20-32% Wing Chord

*Note: Meets FAA Sport Pilot Regulations at maximum continuous power at Sea Level, as required. Read More...


A New Generation
of Airframe Kit

At the time of it's introduction, the Onex Complete Airframe Kit and Sub-Kits were the most advanced kits ever produced by Sonex Aircraft, LLC. All features included in our Complete Airframe Kit description web page are included in the Onex kit, including some new features and additional parts making the aircraft even easier to build!

Onex kit advancements paved the way for upgrades made to other Sonex Aircraft kits in recent years, including more laser-cut parts, formed parts, and machined parts, along with the introduction of the Matched-Hole Formed Parts Kit. The Matched-Hole Formed Parts Kit allows many Sonex Aircraft kit parts to cleco together right out of the box!

This enhancement not only saves construction time and improves accuracy, but also greatly simplifies the Onex plan set with many fewer part details required for builder fabrication. This results in fewer plan sheets.

The Onex kit also features more CNC machined parts, and the impact in-terms of time savings of the Machined Angle Component Kit upgrade is greater with the Onex than other Sonex Aircraft kits.

Another enhancement of Onex vs. Sonex kits is that the Pre-Assembled Main Wing Spars are riveted like the Sonex Spars, but also have the attach bolt holes drilled up to final size. The 3-part wing spar is drilled in a fixture and matched as a set, ready to be installed in the fuselage. These assemblies are also up-drilled and ready for the remaining hardware to be installed by the builder.

Large Onex Cockpit

The large Onex cockpit will accomodate a wider-range of pilots than ever before. Read More

Two Ways to Build

The Onex can be built using a Complete Airframe Kit, or via Sub-Kits. See our pricing page for complete Onex kit pricing and details.

More Versatility Than Ever

The Onex folding wing feature adds tremendous versatility to the aircraft's design, but there are additional features making the Onex design more versatile: The Onex cockpit is enlarged to accomodate a wider range of pilots than ever before, and Onex rudder pedals can be installed at varying locations, allowing builders to adjust their distance from the seat; Landing gear configuration can also be more easily changed with a universal repositionable main gear and a universal engine mount that does not need to be changed when switching between standard gear and tricycle gear configurations.

Onex Development Archive

The Onex design concept was first unveiled at EAA AirVenture Oshkosh 2009, and has become one of the most-anticipated new product offerings from Sonex Aircraft, LLC to-date. Since unveiling, the aircraft's development milestones have been published and archived on the Hornets' Nest Research & Development web site. Continuing updates will be posted to the Hornets' Nest, and distributed to the Onex opt-in email list.

Onex Images

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