• Welcome aboard HomebuiltAirplanes.com, your destination for connecting with a thriving community of more than 10,000 active members, all passionate about home-built aviation. Dive into our comprehensive repository of knowledge, exchange technical insights, arrange get-togethers, and trade aircrafts/parts with like-minded enthusiasts. Unearth a wide-ranging collection of general and kit plane aviation subjects, enriched with engaging imagery, in-depth technical manuals, and rare archives.

    For a nominal fee of $99.99/year or $12.99/month, you can immerse yourself in this dynamic community and unparalleled treasure-trove of aviation knowledge.

    Embark on your journey now!

    Click Here to Become a Premium Member and Experience Homebuilt Airplanes to the Fullest!

My Design & Construction

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

GESchwarz

Well-Known Member
Joined
Oct 23, 2007
Messages
1,250
Location
Ventura County, California, USofA.
Over the past several months I have refered to my design. The following is a quick description. Please look it over and tell me what you think is wrong.

I've included some photos of the 1/10 scale model. I'll take some pictures of the tail assembly the next time I have it all together.

At the present time I have completed most of the parts of the horizontal and vertical tail assemblies. Actual assembly is awaiting the completion of my PVC foam and adhesive testing, which is coming soon.



Description of the Schwarz G8



The G8 is a prototype two-place tandem seat experimental aircraft designed and built by Gary Schwarz. The Vans RV-8A has been used as an engineering baseline. Although some hardware and sub assemblies may be used from Vans, the G8 is essentially a scratch-built ship.

The G8 is designed to be easy to transport on the road and store within a 22’x8’x8’ storage envelop, it therefore has Leroy Grumman’s “Sto-Wing” type folding wing geometry and twin vertical tail surfaces to reduce height. The Sto-Wing design is what is used on so many Grummans including the Wildcat, Hellcat, Avenger and Hawkeye. The clevis type hinges are machined 4130 steel, and there are redundant locking pins. There are many other types of wing folding methods, but none are as cool or elegant as the Grumman Sto-Wing design.

The name “G8” comes from two of this design’s greatest contributors, the Grumman folding wing and the popular high performance Van’s RV-8A. Numerous other design features have also been adopted, most notably are the safety features of the Mooney and Naval Aviation.

Safety and crashworthiness are high priorities in this design. See below for a list of safety features.

Performance improvements on that of the RV-8A are focused on glide slope, climb rate, and landing speed. The span has been increased from 23’ to 29’. Low landing speed is desirable, so large span, large displacement slotted flaps have been included. For superior glide slope control, large speed brakes are included forward of, and at mid-span of flaps.

Adverse landing conditions are addressed with long-travel, trailing link landing gear design. Shock absorbers are also employed, which will eliminate all tendencies to rebound back into the air following touchdown.

Because of the 8’x’8 design envelop restriction, the horizontal tail span is small for this class. The twin vertical surfaces at the tips prevent tip loss, making the horizontal surface more effective. The horizontal stabilizer is also trim adjustable, further increasing its authority, which is especially needed to counter act the large flap pitch moment and the tandem seat / pilot in front configuration.

Low-drag and laminar flow are also design priorities. The fuselage cross sectional area increases continually from the nose, all the way back to the wing trailing edge, where there is a gradual transition to convergent cross sectional area to the tail. The Riblett GA37-318 airfoil is a high lift, laminar flow design. All riveting is flush and many skin panel areas are adhesively bonded in lieu of rivets.

All skins are 6061 T6 instead of 2024 T3, which are typically found on a ship of this performance class. 6061 T6 is weaker in tensile but equal in modulus of elasticity or resistance to compressive buckling. 6061 T6 has superior resistance to corrosion, which is a very desirable characteristic on this design, which employs adhesive bonding. Bond joints can be compromised by corrosion over time. Because of the reduced tensile strength of 6061 T6, rivet spacing is reduced and the wing and tail thickness are increased which reduce tensile loads.

Adhesive bonding will be used to attach many areas of the aluminum skin. Much research and testing has been performed to characterize the capabilities and limitations of various adhesives, and to understand the effect of various materials and part geometries being joined. Good design insures that no adhesive joints are subjected to any peel load vectors. The purpose of bonding as a method of attachment is to reduce build time and achieve improved surface contour. Rivets will be used typically around the skin panel perimeters and in areas where vibration, peel risk and higher loads exist.

Power is supplied by a Mazda rotary engine. This engine has no mechanical failure modes that are particular to the rotary that can result in total, or sudden loss of power. This engine has a high power to weight ratio and a very small cross-sectional area, which allows for the laminar flow fuselage shape.

Noise reduction is a priority. The engine used in this design produces a very high volume, and this has prompted a new muffler design, which divides the exhaust pulses and distributes them over time resulting in much lowered amplitude and greatly increased frequency output. Many noise reduction materials and techniques will be employed.

Rear passenger comfort is dramatically increased with a 360 degree swivel seat and extra wide cockpit width which enables the passenger to sit facing in any direction to obtain a greater view of the ground, which is ordinarily limited by the low wing while looking forward.


SPECIFICATIONS






Seating: 2-place, tandem
Gear: Tricycle, Trailing Link w/ shock absorbers



Powerplant: Late generation Mazda Rotary “Renesis” 13B, 250 hp @ 5500 rpm
PSRU, Fuel and Ignition Systems
By Real World Solutions, Fla.
Length: 22’
Span: 29’
Height: 7.5’
Weight, Empty: 1200 lb
Weight, Gross: 1800 lb
Wing Area: 120 sq ft
Airfoil: Riblett GA37-318
Wing Chord: 52”
Fuel Capacity: 45 gallons
Cockpit Width, Pilot: 27”
Cockpit Width, Passenger: 31”
Ailerons: Frise type
Flaps: Hinged Fowler
Stabilizer: Trim Adjustable

Materials:


Cockpit Cage & Engine Mount: Welded 4130 Steel
Airframe: Riveted 2024 T3


Skins: Riveted and Bonded 6061 T6
Flight Controls: Stick, push/pull tube throughout except rudder cables.





SAFETY & CRASHWORTHINESS FEATURES

of the Schwarz

G8



From the very beginning safety has been the number one and over-riding priority, and has dictated the design of this aircraft from its general configuration all the way down to the individual piece parts.




  • Cockpit roll caged constructed of welded 4130 steel tube. This is the type of occupant protection provided in automotive racing. Because this structure is stronger than all that surrounds it, the surrounding structures will absorb a greater percentage of the energy as they breakaway in a violent crash.
  • Long-stroke, shock absorbing seats to reduce risk of back injury.​
  • Long-stroke, trailing link landing gear of the type used on the Navy’s FA-18. This gear is designed for hard landings. More importantly, once you contact the ground, the energy dissipating shock absorber prevents the aircraft from rebounding back into the air; the plane is on the ground to stay. Many fatalities have occurred after the aircraft has returned to the air at low speed in an uncontrolled manner.​
  • Tricycle landing gear configuration.​
  • Large trim-adjustable horizontal stabilizer for maximum authority for forward CG shift.​
  • Five-Point Seatbelts.​
  • Energy absorbing fuselage sub structure utilizing a low-wing configuration with extra deep spar, and a thick double-shear panel cockpit floor. Part of the engine coolant system has been located there which aids as a barrier and absorber of energy.​
  • Anti-Stall/Spin features include vortex generating leading edge stabilizer gloves to prevent stalling of the horizontal stabilizer. Forwarded mounted twin vertical tails to prevent blanking.​
  • Angle of Attack indicator to warn of approaching stall and to aid monitoring for adequate lift.​
  • Heavy elevator control to provide feedback to pilot. Use of bobweight.​
  • Harry Riblett’s GA37A318 airfoil and “Hershey Bar” wing planform for predictable, soft stalls.​
  • Large Fowler type flaps to achieve low stall speed.​
  • Mazda rotary engine, which has no mechanical failure modes that would cause an engine shutdown. Only the seals can fail, in which case only a minor reduction in power would result.​
  • Redundant and separated fuel and ignition systems.​
  • “Padded Cell” cockpit designed to eliminate sources of injury to the occupants in a crash.​
  • Redundant quick release canopy mechanism.​
  • Fuel tanks located away from the cockpit, behind the main wing spar, outboard of the wing center section.​
  • Fire extinguisher.​
 

Attachments

  • Rear.jpg
    Rear.jpg
    52.5 KB · Views: 454
  • IMG_3748.jpg
    IMG_3748.jpg
    34.1 KB · Views: 542
  • IMG_3745.jpg
    IMG_3745.jpg
    34.5 KB · Views: 496
  • IMG_4577.jpg
    IMG_4577.jpg
    59.7 KB · Views: 531
Last edited:
Back
Top