Design Genesis and Innovation
John Hatz of Gleeson, Wisconsin, conceived the CB-1 in 1968 out of necessity rather than commercial ambition. Unable to find an affordable biplane that met his exacting standards, Hatz designed his own aircraft as a smaller, more economical alternative to the expensive Waco F series biplanes that dominated the vintage aircraft market. The first prototype, christened "Happiness" by Hatz's young daughter, made its maiden flight in April 1968 powered by an 85-horsepower Continental engine.
Hatz's design philosophy centered on providing amateur builders with an aircraft that was simple to construct yet delivered excellent performance and forgiving slow-flight characteristics. This approach proved revolutionary in homebuilt aviation, offering quality biplane construction at a fraction of the cost of factory-built alternatives.
Production and Distribution Model
The CB-1 entered the Experimental amateur-built category on April 18, 1968, establishing a unique production model that continues today. Rather than traditional factory manufacturing, the aircraft has been produced exclusively through plans and kits distributed by multiple suppliers over five decades. Merrill Airways of Merrill, Wisconsin, initially distributed the plans, followed by various organizations including Makelan Corporation of New Braunfels, Texas, and the Hatz Biplane Association of Gurnee, Illinois.
This decentralized approach enabled continuous availability and evolution of the design. By 2011, more than 150 examples had been completed by amateur builders worldwide, with aircraft registered in the United States, Australia, and New Zealand. The aircraft achieved international recognition when a New Zealand example (ZK-PEC) was registered in November 2004 and painted in Buzzard Airlines markings at Tauranga.
Technical Excellence and Variants
The CB-1's construction combines proven materials and techniques: a welded steel tube fuselage frame supporting wooden wings with fabric covering, fixed tailwheel landing gear in the Piper Cub style, and four-aileron configuration for responsive control. The 25-foot 4-inch wingspan incorporates a Clark Y airfoil with a 6.06:1 aspect ratio, contributing to the aircraft's excellent slow-speed handling.
Engine flexibility became a hallmark of the design, accommodating powerplants from 85 to 150 horsepower. The most common installations included the 100-horsepower Continental O-200 and 115-horsepower Lycoming O-235, though builders have successfully fitted everything from 65-horsepower Continental C85-12 engines to 145-horsepower Warner seven-cylinder radials.
Billy Dawson of Seguin, Texas, created the most significant variant with his Hatz Classic design featuring a stretched, more rounded fuselage reminiscent of 1930s aircraft. The first Hatz Classic flew in 1996 and earned plansbuilt Grand Champion honors at Oshkosh in 1997. Dudley Kelly contributed the Kelly-D variant in 1977, simplifying construction by removing the wing center section, while the modern Hatz Bantam was developed to meet American Light Sport Aircraft regulations.
Performance and Capabilities
With a typical 100-horsepower engine installation, the CB-1 achieves a maximum speed of 105 miles per hour and cruises comfortably at 85 miles per hour. The aircraft's 38-mile-per-hour stall speed and 600-foot-per-minute climb rate provide excellent short-field performance, requiring only 400 feet for takeoff and 300 feet for landing under normal conditions.
Weighing just 875 pounds empty with a maximum takeoff weight of 1,600 pounds, the CB-1 holds the distinction of being the lightest two-place biplane available to amateur builders. Its +5G/-3G design parameters permit light aerobatic flight, adding to its versatility and appeal among recreational pilots.
Enduring Legacy
The CB-1's most remarkable achievement lies not in production numbers but in its sustained impact on homebuilt aviation. More than 55 years after its first flight, the original prototype "Happiness" remains airworthy, symbolizing the design's durability and continued relevance. The aircraft's success spawned an entire family of related designs and established a template for affordable homebuilt biplane construction.
The Hatz Biplane Association maintains an active community of builders and operators, ensuring continued availability of plans, technical support, and parts. Examples continue flying worldwide, from weekend recreational flights to airshow demonstrations, proving that John Hatz's vision of accessible, high-quality biplane aviation remains as relevant today as it was in 1968.
The CB-1's influence extends beyond its immediate variants to inspire countless other homebuilt biplane designs, establishing principles of simplicity, affordability, and performance that continue to guide amateur aircraft construction. This enduring legacy represents perhaps the greatest measure of the design's success in democratizing biplane aviation for generations of builders and pilots.