Barnett J4B Gyroplane

Barnett J4B2 gyroplane gyrocopter review

Easy-To-Build Single Seat Gyrocopter

ARTICLE DATE: October 1979

JERRIE BARNETT, an Olivehurst, California, machinist and self-taught gyro-pilot, has come up with a fine little single-place Barnett J4B gyroplane homebuilt for the do-it-yourself amateur with some knowledge and skill in acetylene welding.

Jerrie Barnett with JB gyroplane

Engine running — Jerrie Barnett getting ready to climb in.

Requiring standard aircraft construction techniques and a minimum of technical equipment, the Barnett J-3M can be built for anywhere from $1,500 to $8,000, largely depending on the price of the engine selected.

It has flown with a 65-hp Continental, but Barnett says it was designed for 85 horses and can use other powerplants up to 100 hp, beyond which the engine weight becomes a limiting factor.

ray barber photograph gyrocopter

It was back in 1962 that Barnett first became interested in gyros, when he built up rotor blades and a control head from Bensen gyro-glider kits, installed them on a training trailer of his own design and manufacture, and proceeded to teach himself how to fly.

Mastering that, he developed an original rotary-wing glider, the J-1, and soon decided to add power for free flight. In 1963 Barnett converted a Volkswagen engine of 34 hp and installed it in the J-1. and mastered the fine art of piloting his gyroplane without the aid of a tow-rope.

john olafson photographer gyrocopter

That engine served its purpose in the J-1 as a trainer, the J-2, and the following year Barnett graduated to the bigger J-3M gyroplane design, which could take a Continental aircraft engine of either 65 or 85 hp.

First flight-tested by CFI Tom DeKellis at Marysville, the J-3M gyroplane prototype has since logged several hundred trouble-free hours of flying and proved capable of climbing to a service ceiling of 6000 feet, on a power-to-weight ratio of 10:1, the J-3M weighing 650 pounds gross.

With the C-85 engine installed, says Barnett, the Barnett J4B gyroplane service ceiling has been increased by more than a factor of two, up to 14,000 feet MSL, and with a gross weight of 750 pounds, its power-to-weight ratio changed to 8.8:1.

solid gyrocopter nosewheel barnett

Nose gear assembly is steered through rudder pedals, has special stop link to facilitate crosswind landings.

Called the Barnett J4B gyroplane with the bigger engine installed, its cruising speed has been increased from 70 mph to 90 mph, Vmax upped from 85 mph to 115 mph. and with 12 gallons of fuel instead of seven, its range has been stretched from 120 to 250 miles.

Both the J-3M and the J-4B gyroplanes, have 23-foot diameter rotor blades with a 7¼-inch chord, but the J-4B rotor’s rpm is 425 in flight compared to 400 rpm for the J-3M. The J-4M gyroplane climbs faster at 700 fpm (compared to 500 fpm for the J-3M) but takeoff run (200 feet) and landing roll (0-20 feet) are the same.

A homebuilder with basic welding skills can do all the required welding, or he can purchase a completely welded airframe for the J-B4, ready for painting, for $2,000.

Jerrie Barnett flying

Only a small acetylene welding outfit is required to assemble the Barnett J4B gyroplane airframe from 4130 .035 aircraft tubing, and the only other tools required are a drill press and a 10-inch lathe, plus the usual shop hand tools.

With the exception of the curved nose section, which is made of fiberglass, all Barnett J4B gyroplane fuselage and empennage covering is of doped fabric, with plexiglass used for window panels.

The controls are standard fixed-wing aircraft type — a joystick and rudder pedals linked to a steerable nosewheel, and a brake pedal that operates equalized disc brakes, with throttle lever and a push-pull carburetor heat control.

J 4B gyrocopter cockpit

Instrument panel in J-4B cockpit with fuel selector valve at lower left. Body is made from high-heat resin.

Instruments include airspeed indicator, altimeter, a three-in-one oil-temperature/pressure and fuel gauge, engine and rotor tachometers, plus two on-off toggle ignition switches. The gas tank, fabricated of aluminum, is mounted under the pilot seat and uses a visual gauge from an outboard motor tank, plus a hand-operated squeeze-bulb for emergencies.

The J-3M has a tricycle landing gear with a small, solid rubber tailwheel to protect the rudder from damage during nose-high landings. The main gear is rigidly fixed to the airframe, and landing loads are absorbed by oversized, under-inflated tires. The mains have cable-actuated equalizing disc brakes which can be used together or independently as desired.

The J-3M has a gimbal head of Barnett’s own design, machined from aluminum alloy with a steel spindle turning in one bearing, with grease nipples provided for lubrication The spindle control head assembly is described by Barnett as a compact, high-strength design for long life and dependability.

Its single rotating bearing and large spindle. Barnett claims, make the design superior to others. The rotor hub and blade assembly Barnett designed also for servicability and long life. The hub is built in three sections with a built-in cone angle, each blade independently adjustable for pattern as well as pitch, he explains.

The blades are made from close-grained spruce with an internal steel spar for constant chordwise balance, covered with fiberglass for full flexibility and added strength and finished with epoxy. Streamlining of the blades is unmarred by extra weights or protrusions, other than faired-in trim tabs.

Barnett explains the difference between the J-3M and the Barnett J4B gyroplane this way:

“The J-3 is the utility model, rugged, dependable and easy to construct for the beginner, with an operating cost of around $2/hour. The J-3 is ideal for traveling to and from work, flying around the ranch, up to your favorite fishing hole or just cruising around. The J-4 is, on the other hand, the showoff, with its streamlined design, faster cruise and sleek look.”

However, Barnett doesn’t recommend the J-4M for beginners, as it requires a higher standard of workmanship and experience.

Gyroplane pilot ratings are available from the FAA, but are not required to fly one, says Barnett; you may fly with a fixed-wing student, private or commercial ticket, but beginning builders with no flight experience should get some dual instruction in conventional aircraft prior to flying the gyro.

Jerrie Barnett J 4B gyrocopter

Climbing out, preparing for right-hand climbing turn. The J-4B will climb 3000 fpm with a 100-hp Continental.

A two-place design is under development, says Barnett, as well as a prerotator bolt-on unit to spin the blades up to takeoff rpm. Currently, an engine-driven torque converter and synchro-mesh clutch are used to pre-spin the rotor prior to takeoff.

The prerotator can only be engaged with the engine idling, and a spring-loaded lever in the cockpit is automatically released when the blades reach full prerotation speed of 240 rpm. Another new development is a set of 16-pound aluminum floats, and slightly heavier plastic floats, expected to be priced between $300 and $500.

Barnett describes the flight characteristics of the J-4M as “about the same as those of a small plane, except that there is much less bouncing in turbulence. Turns are coordinated with stick and rudder movement, with the stick controlling the angle and attitude of the blades fore and aft, and side to side. The horizontal stabilizer and elevator are one piece, mounted in a fixed position.”

JB Gyroplane design

LEFT: Supported by 5/8 in .035 4130 tubing, each leg.
RIGHT: Equaflow exhaust system with carburetor heat muff on Continental engine. Note brake disc made from plywood-saw blade.

The J-4M is capable of slow flight down to 30 mph IAS, while its normal cruise is between 70 and 90 mph IAS. The C-85 burns 80/87 octane fuel at around 5!/a gph Says Barnett: “A normal takeoff on a non-wind day might take as much a s 50 to 75 feet with a the EAA, a freak occurrence on April reasonable headwind component.”

“If the engine quits, you can autorotate down to a safe landing almost anywhere, with a 5-to-10-foot rollout. It won’t stall or spin, but you must have room enough to take off again. The South Forty would be a great place to fly, if it were smooth enough to get off without shaking yourself and your gyrocopter to pieces!”

JB4 gyrocopter continental engine

Barnett reports that more than 100 sets of plans have been sold and about 60 are flying. Only one accident to a Barnett gyroplane has been reported by 14, 1979 at El Mirage Dry Lake in Southern California.

Truman Conkle, Barnett’s area distributor, was killed when his J-4B tangled with a 2000-foot tow cable, as a car towing a glider inadvertently crossed his flight path. Currently, Barnett’s Southern California distributor is Tim Painter of Southern California Sport Aviation. Painter assists homebuilders working on their Barnett gyroplanes.

BARNETT J-4B GYROCOPTER SPECIFICATIONS
Engine 85 hp
Rotor Diameter 23 ft
Blade Chord ¼ in
Rotor RPM 425
Height 7 ft 8 in
Length 12 ft 2 in
Empty Weight 441 lbs
Cross Weight 750 lbs
Fuel Capacity 12 gals
Max Speed 115 mph
Cruising Speed 90 mph
Service Ceiling 14,000 ft
Rate of Climb 700 fpm
Range 250 miles
Takeoff Run 200 ft
Landing Roll 0-20 ft

Jerrie Barnett Gyrocopter

Barnett J4B gyro

The Barnett J4B is a small gyroplane marketed in the United States by Barnett Rotorcraft for homebuilding. Originally flown as the J-3M with an open cockpit and fabric-covered sides, later versions have a fiberglass cockpit pod either partially or fully enclosing the pilot.

Apart from the basic J4B, versions available in 2007 included the BRC540 (two seats side-by-side) and J4B2 (two seats in tandem). A J4B2 piloted by Ron Merkle holds a coast-to-coast speed record in the United States for gyrocopters.


ARTICLE DATE: February 1994

Barnett J4B gyroplane display

Barnett uses conventional construction techniques, a tubing and fiberglass body, and tube and fabric tail section. The result is a simple, sturdy bird with an excellent safety record.

A 100-hp Continental 0-200 engine (a Subaru engine is also a choice) provides a cruise speed of 105 mph. The Barnett J4B gyroplane gyro holds enough fuel for about three hours’ flight, so cross-country trips are no sweat.

The aluminum rotor on the J4B is 23 feet in diameter; length, 12 feet 4 inches: height. 7 feet 8 inches. Empty weight is 512 pounds, and it can accommodate a payload of 285 pounds. The factory estimates 425 hours of building time.

Barnett Gyroplane Varients

J4B: Single-seat autogyro with 23 ft rotor.

J4B-2: Two-seat variant of the J4B with a 25ft 4in rotor.

One of the few gyroplanes available with standard aircraft powerplants. Jerry Barnett has taken a very conventional approach to gyro design.

The Barnett gyros are simple, hearty flying machines with excellent manners, dependable structures, and absolutely no tricks.


Barnett J4B Gyroplane

  • Design/Engineering: C+.

  • Ground Handling: C+.

  • Gear is a bit narrow, not for rough fields.

  • Flight Characteristics: B-.

  • Company Profile: C. Simple folk doing good business.

  • Kit/Plans: C. Nothing elegant… but not expensive, either.

  • “Bang For The Buck”: B.

  • Risk Factor: 5.

  • Final Grade: B-.


Specifications (typical J4B) General characteristics
Crew one pilot
Length 12 ft 4 in (3.76 m)
Main rotor diameter 23 ft 0 in (6.10 m)
Height 7 ft 8 in (2.34 m)
Empty weight 530 lb (240 kg)
Gross weight 880 lb (400 kg)
Powerplant 1 × Continental O-200, 100 hp (75 kW)
Performance Maximum speed 125 mph (200 km/h)
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Summary
Barnett J4B Gyroplane
Article Name
Barnett J4B Gyroplane
Description
Through a number of designs, Jerrie Barnett produces the beautiful Barnett J-4B gyroplane. The Barnett J4b gyroplane is an excellent , very capable - stable cross-country gyrocopter.
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