The Windecker Eagle was produced in the late 60s-early 70s. The type was the first civil A/C to be built almost entirely of fiberglass--note the Dow Chemical logo on the tail. The FAA dragged its feet about certification--they only certified it for two people, though its a four-place A/C. The venture went broke.
The Eagle was possibly the first civil aircraft to be constructed entirely (except for critical structural components) of glass fiber, a reinforced resin plastic called Fibaloy. Interesting property of chemical composite such as Fibaloy is that it gains strength as it ages; Dow tests showed a gain of 23% in 5 yrs. Nevertheless, FAA asked that aircraft be over-designed by 20% because of lack of experience with fiber structures. Developed by Dr. Leo Windecker, Texas dentist, under exclusive license from Dow Chemical Company. An aircraft (not Eagle) using this material first flew 7 Oct 67. First Eagle I prototype crashed while doing spins during FAA certification tests. Although it recovered well with c.g. in forward position, failed to recover from a spin with c.g. in more rearward position. Test pilot Bill Robinson bailed out and landed safely. Plastic wing was one of lightest ever used on an aircraft of this type and weight. As a result, more mass than usual concentrated in tail. This, coupled with some possible blanking of airflow over vertical tail, led to redesign including addition of a ventral fin. Certification of the redesigned second prototype successful; however, only 6 produced 1970-1. 1 bought by USAF and designated YE-5A; was used to test radar detectability of synthetic fiber aircraft and later turned over to Army for further tests. 1971, production of Eagle I ceased due to funding problems. 1977, Jerry Dietrick became interested in Eagle and had plans for producing Eagle I and a model II. Lack of financing and drop in demand for light aircraft ended his plan and none was produced. It and its primary competition, Beech Bonanza 35B, comparable in performance and cost-- about $40,000 in 1970. By late 70s (when Dietrick became interested), price of Bonanza about $95,000; Dietrick planned to sell Eagle I for about $112,000. Dr. Windecker joined Avtek Corporation 1982 and contributed to development of Avtek 400, a composite aircraft using DuPont Kevlar and Nomex aramid fiber.