The long-anticipated Two-Seat SubSonex JSX-2T was unveiled at a record-breaking EAA AirVenture Oshkosh 2022, providing the first opportunity for the public to see the new jet prototype. JSX-2T was first unveiled during the Sonex Open House and Homecoming Fly-In the day before AirVenture began, and was then moved to the Sonex exhibit booth on AirVenture grounds where it was on-display during the show.
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Subject to the SubSonex JSX-2T Kit |
How Big is Big Enough?
Many people tried-on the aircraft during the week of AirVenture, and it soon became clear that the JSX-2T cockpit was enormous! Even extremely tall pilots had a lot of excess head room, leaving us to question: How big is big enough? Our experience with the JSX-2T unveiling at AirVenture, confirmed by a couple of our much taller Sonex staff members has taught us that even very expensive CAD model simulations of people cannot accurately estimate the ergonomic nuances of cockpit fit, and a change is in-order for JSX-2T.
A Design Tweak: Sleeker, Lighter, Better Performance
Sonex is in the process of lowering the turtledeck and aft canopy bow by approximately 3.5 inches. The forward canopy/windshield bow will be lowered approximately 2.2 inches to suit the aircraft’s new lines while retaining a good forward sight line. This change will still fit our very tall and long-torso’d employee, James, who is 6’4″ tall with only a 30″ inseam. In addition to sleeker aesthetics for JSX-2T, the change will reduce structural weight for the airframe, helping us to meet our empty weight targets and will more importantly reduce frontal area and improve flow to the PBS TJ100 engine intake. While we’re not changing any previously published performance estimates, these changes will help ensure that those estimates can be met or perhaps exceeded.
As of this wrting, progress in contstructing the SubSonex JSX-2T prototype has taken a step backward to integrate this change. The original turtledeck, canopy and windshield have been removed from the aircraft, and the tail has been removed to access the aft-most fasteners in the turtledeck. Flat patterns for the new turtledeck formers have been cut and tooling for our hydropress is in-progress to form these parts, and the new turtledeck skins have been cut. We should have the new turtledeck back on the aircraft very soon and part files for new canopy bows are being sent to our machinist.
Kitplanes editor and JSX-2 customer Paul Dye, while not especially tall, was absolutely swimming in the giant cockpit of the JSX-2T prototype at AirVenture, even with a 2″ thick seat cushion.
Sonex staff member Nathan is 6 foot, 2 inches tall with a 34 inch inseam, and still has approximately 5.5 inches of clearance to the canopy.
Another change vs. what was displayed at AirVenture 2022: The instrument panel and glare shield will get the rounded profile shown in JSX-2T CAD renderings, and the forward end of the glare shield will meet the bottom of the windhield similar to our B-Model aircraft. The faceted instrument panel and glare shield shape seen on JSX-2T at AirVenture was installed merely in the interstests of time to get the jet ready to display at the show.
Minimal JSX-2T’s Development Schedule Impact
Thankfully, these changes will not represent a very large impact to the development schedule for JSX-2T. Heading into the colder weather months here in Oshkosh, we will complete this change and progress to completion of the remaining airframe structural construction tasks, then proceed to systems installation. We are targeting the early Spring of 2023 to begin the test flight program, and a late Spring/Early Summer opportunity for Kit Reservation Deposit holders to turn their pre-orders into full orders with kit production beginning in the Summer.
Sonex staff member James is 6 foot, 4 inches tall with only a 30 inch inseam. Although his head is leaning-back in this picture, he has approximately 4 inches of clearance to the canopy with head upgright looking straight ahead.
Another view of 6 foot 4 inch tall James with the SubSonex JSX-2T canopy closed.
Difference between new and old turtledeck former profiles at the aft canopy bow.
Difference between new and old windshield bow profiles at the front of the canopy.
Engine inlet profile in original configuration.
Engine inlet profile in the new configuration.
Sleek new aircraft profile in side view.
New aircraft profile in front quartering view.
Place Your JSX-2T Deposit Today!
Beginning July 1st, 2022 Sonex is accepting refundable* Kit Reservation Deposits to get customers in-line for JSX-2T kit shipments:
- Deposit Amount: $15,000*
- Total Quick Build Kit Price (EAB Kit): $66,000
- Ultra Quick Build Kit Price (Exhibition): $74,000
- Estimated Total Build Cost (including kit, engine, avionics & upholstery): Under $155,000**
*Kit Reservation Deposits may be cancelled less a $1,500 cancellation fee. See full Deposit Terms & Conditions for details.
**Completion costs subject to change with 3rd party price increases. See Current SubSonex JSX-2T Completion Cost Estimates.
Kit production estimated to begin during the 2nd Quarter of 2023, with shipments estimated to commence during Fall/Winter, 2023.
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Subject to the SubSonex JSX-2T Kit |
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What Will My Project Cost?See detailed pricing below with our cost estimating worksheet* and see why Sonex aircraft offer the Best Sport Aircraft Performance Per Dollar!
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There are many outstanding features to the SubSonex JSX-2T, some are continuations and extensions of existing Sonex aircraft features and some are new and unique to JSX-2T.
Removable Wings:
Like all Sonex aircraft, SubSonex JSX-2T will feature removable wings. JSX-2T main landing gear will be attached and retract into the center section wing, as it does on the single-place SubSonex. Also like JSX-2, JSX-2T will utilize machined wing attach ties, however, the higher gross weight of the aircraft requires four ties per wing instead of two, and the ties have been redesigned and resized for the specific loading and strain properties of the JSX-2T wing spar. Each tie will have three bolts per-side vs. four bolts in JSX-2. This will minimize the increase in the number of bolts that need to be removed in order to remove the wing panel to 12 bolts per wing instead of 16. Design and testing of new the ties is complete. A static load test of the entire wing structure will take place after AirVenture 2022.
JSX-2T outboard wing skinning in-progress.
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Landing Gear System:
The retractable gear system for JSX-2T will be different than that used in the single-place jet. Instead of using pneumatic cylinders, Sonex is using electric linear actuators for each gear leg. Use of electric linear actuators will reduce weight by eliminating the need for air pumps and accululator tank, and elminates the need for a gear up-lock system.
Due to the larger size and increased max. gross weight of the JSX-2T, the diameter of the wheels will be enlarged, which allows larger, more powerful brakes to be used. The system will use a scaled-up version of the main gear trucks/brake units currently featured in SubSonex JSX-2. The gear legs are also lengthened to give the aircraft more ground clearance — an aesthetic consideration making the aircraft look “right” in its scaled-up form that will also prevent the jet’s larger wing area from increasing float in ground-effect.
Control System:
Like the Sonex, Waiex and Xenos B-Models, SubSonex JSX-2T will utilize a single center-mounted control stick to minimize weight and maximize useful load and performance. Routing and geometry of all control system components have been designed, structural requirements for the control system components have been analyzed, and prototype control system parts are in-process.
Fuel System:
The aircraft will have 10 additional gallons of useable fuel capacity vs. the single-place jet, offering a moderate increase in range and endurance while still keeping the aircraft within its intended max. gross weight and an acceptable CG range. Like the single-place JSX-2, the JSX-2T fuel cell will be removable for maintenance access to other components in the fuselage.
CG and YES: Baggage!
With a max gross weight of 1500 lbs and and estimated empty weight of 620 lbs, the JSX-2T will have great flexibility in CG and loading options. With the side-by-side seating configuration, the 50 gallon fuel cell is positioned on the CG and is wide, allowing a lower total fuel tank height which offers extra space above the fuel tank and on the CG for various combinations baggage, BRS system, smoke oil or auxiliary fuel. Space is still available in this area after the change in turtledeck height/profile discussed in this update. SubSonex JSX-2T will also offer a first for Sonex aircraft: dual aerobatics with an aerobatic max gross weight of 1100 lbs.
Area shaded in green is available above the fuel cell for baggage, BRS and even aux. fuel!
Estimated Weight and Balance studies of JSX-2T show versatile loading options.
Fuselage and Cockpit:
Design of the fuselage is driven primarily by the design and interface of other major aircraft components including the wing, tail, fuel system, engine mounting etc. The cockpit has the largest impact upon the design of the fuselage and much work has been focused on the cockpit design of JSX-2T to accommodate two occupants comfortably, including tall pilots, with access for both pilots to controls. Several features of the JSX-2T cockpit have been designed to make this possible:
- Curved Fuselage Sides: The forward fuselage/cockpit side walls of JSX-2T are curved. Like “bubble doors” on a high-wing aircraft, these curved cockpit side walls give pilots more room at the elbows and hips. This amounts to a 2″ total increase in cockpit width in these areas vs. our earlier aircraft designs with straight longerons and fuselage side walls, however, there is a structural requirement for a straight section at the upper longerons making shoulder room comparable to Sonex aircraft B-Models.
- New Canopy and Turtledeck Shape: The traditional arc of typical Sonex Aircraft turtledeck formers and canopies has been changed for JSX-2T, reducing the total height of the apex of that arc while making the arc taller at either side of the aircraft centerline. This gives pilots an increase in head room while minimizing the total height of the fuselage.
- Ample Leg Room: Like the single-place SubSonex and the Onex, JSX-2T does not have the constraints of an angled firewall or forward bulkhead for landing gear mount provisions. This gives the cockpit ample leg room and the ability to vary the distance of the rudder pedals from the seat.
In SolidWorks modeling of the cockpit, we are able to fit a 95th percentile 6′ 3″ tall person of even proportions into the aircraft. Fit will vary from one individual to the next, however, as ratio of inseam vs. torso length varies, along with weight, and each individual’s perception of a comfortable fit in an aircraft. Like any aircraft, you’ll have to try it on for size, however, pilots of more average height and weight can count on being able to fit in the JSX-2T comfortably.
JSX-2T cockpit cutaway view shows general cockpit layout.
JSX-2T model with 95th percentile, 6′ 3″ tall pilot.
