Development and Financial Struggles
The Sunbird project began in 1983 when De Vore Aviation, primarily an aircraft components manufacturer, ventured into complete aircraft design for the first time. Company founder Gilbert De Vore established the ambitious goal of creating a two-seat aircraft that could sell for under $20,000 with operating costs half that of conventional light aircraft. By 1985, when funding became available and the Verilite subsidiary was formally created, the projected price had risen to $22,000, climbing further to $24,000 by 1987.
Financing proved the project's greatest challenge. De Vore personally contributed three-quarters of the $1 million spent on development through 1986, while attempts to secure additional funding through public offerings failed despite plans to raise between $1 million and $25 million for certification and production.
Innovative Design Solutions
The Sunbird employed an unusual configuration that set it apart from conventional light aircraft. Its high-wing design featured strut bracing and a pusher-mounted engine positioned at the rear of the wing, with the empennage carried on aluminum booms. The pilot and passenger sat side-by-side in a fully enclosed cockpit above fixed tricycle landing gear, providing excellent visibility and ground handling characteristics.
A critical design flaw emerged during radio-controlled model testing when the aircraft demonstrated a tendency to enter unrecoverable spins following stalls. Verilite collaborated with NASA's Dryden Flight Research Center to address this dangerous characteristic. The solution involved adding droops to the outboard sections of the wing's leading edges, which eliminated the spin tendency and rendered the Sunbird "unspinnable" according to test results.
Test Flight Disasters and Triumph
The first flight attempt on April 18, 1987, ended in immediate disaster. The prototype crashed shortly after takeoff when it could not maintain altitude after leaving ground effect. The National Transportation Safety Board investigation revealed that while the Emdair CF-092B engine was rated at 60 horsepower, it could only deliver 40 horsepower under actual conditions—insufficient for sustained flight.
The crash led to a complete rebuild of the aircraft. Engineers removed 150 pounds of structural weight and modified the engine to produce 70 horsepower instead of its original 60-horsepower rating. These modifications proved successful when test pilot completed the first successful flight on October 5, 1987, nearly six months after the initial attempt and more than a year behind the original May 1986 target date.
Engine and Technical Specifications
The Sunbird was powered by the Emdair CF-092B, a four-stroke piston engine that represented a well-proven design based on Weslake production components. Emdair had assumed manufacture of this engine line around 1984 and continued production into the mid-1990s. The CF-092 series was available in both direct-drive and geared configurations, with the Sunbird utilizing the more powerful variant after modifications.
With its empty weight of 760 pounds and gross weight of 1,250 pounds, the Sunbird offered a useful load of 490 pounds. The aircraft's 135 square feet of wing area provided adequate lift characteristics once the engine power issues were resolved. Its compact dimensions—32-foot wingspan, 23-foot 8-inch length, and 8-foot 4-inch height—were designed for easy hangar storage and reduced operating costs.
Legacy of Innovation and Commercial Reality
Despite achieving successful flight, the Sunbird never progressed beyond its single prototype. The combination of development delays, cost overruns, and financing difficulties proved insurmountable for the small company. The aircraft's final legacy lies not in commercial success but in its innovative approach to affordable aviation and its successful collaboration with NASA to solve critical aerodynamic problems.
The project's evolution from "Affordable Airplane" through the contest-winning "Sundancer" name to its final "Sunbird" designation reflected the changing nature of the program itself. What began as an ambitious attempt to democratize aviation through low-cost design ultimately demonstrated the complex challenges facing experimental aircraft manufacturers in certification, funding, and market entry.
No Sunbirds remain in service today, as only the single prototype was ever constructed. The aircraft represents an important case study in the difficulties of translating innovative design concepts into commercially viable products, particularly in the highly regulated and capital-intensive aviation industry of the 1980s.