In 1994, Jay founded Carter Aviation Technologies, LLC, f/k/a CarterCopters, LLC. Carter Aviation is an aerospace research and development firm that has developed a technology, known as Slowed Rotor/Compound (SR/C™) Technology, which couples the speed, range and efficiency of an airplane with the vertical takeoff and landing (VTOL) capability of a helicopter. At its core, SR/C™ Technology represents the simple yet elegant hybridization of airplanes and rotorcraft through remarkable innovations in engineering design.Carter Aviation's technical achievements have been independently verified by NASA, the U.S. Army, and the nation’s top Center for Rotorcraft Excellence at the Georgia Institute of Technology. Its SR/C™ aircraft are protected by more than 20 U.S. patents, many of which have also been filed in foreign patent offices.Importantly, SR/C™ aircraft: (a) have 3 to 6 times the range of helicopters (and 300% to 600% lower fuel consumption); (b) offer cruise speeds from 150 mph at low altitudes to 500 mph at 40,000 feet; (c) have the ability to operate without runways at low cost, which will revolutionize regional civilian air transportation; (d) are the only aircraft capable of transporting large payloads over long ranges to sites requiring VTOL, where local fuel is either very expensive or unavailable; (e) are inherently safe and capable of flight even if all electronic systems fail, and, in the event of fuel exhaustion, normal landings remain possible; and (f) can be scaled in size from small unmanned aerial vehicles (UAVs) to a Boeing 767 equivalent.Carter Aviation's SR/C™ Technology has been featured in various online and print media, including Popular Mechanics, Popular Science, regional print media, and has also been featured on television programming on CBS (60 Minutes), the Discovery Channel, the Speed Network, various regional television networks, among others. In 2001, Carter Aviation receveived Popular Mechanic's Design & Engineering Award.

Carter Aerospace Development, LLC is a subsidiary of Carter Aviation. Carter Aerospace builds protoype aircraft incorporating Carter Aviation's SR/C™ Technology.

Founded in 1976, Carter Wind Systems grew to $7 million in sales and had over 100 employees by 1983. The company installed wind turbines throughout the United States, and from Great Britain to Hawaii to 300 miles north of the Artic Circle. In 1982, ten (10) percent of the company was sold to Hamilton Standard, a division of United Technologies. Jay's ability to develop and market a very lightweight and cost effective wind turbine enabled the company to survive the industry decline in the mid-1980s and to emerge as one of only two U.S. Wind turbine manufacturers still in existence by 1988. In 1992, fifty (50) percent of the company was sold to private investors. Jay negotiated all licensing agreements and the sale of the company. NOTE: Renewed interest in sustainable energy subsequently prompted the creation of a new wind turbine company in 2008, Carter Wind Energy, LLC.

Together with his father, Jay, Sr., Jay developed a steam powered automobile, which was the first car in the world to meet the original 1976 EPA emission level standards. The car could make a cold start in 30 seconds, travel at more than 80 mph, and was featured on the cover of numerous magazines and newspapers nationwide.For his achievements, Jay (at the age of 29) was called to testify before the U.S. Senate, Committee on Commerce and the U.S. House of Representatives, Committee on Science and Astronautics, Subcommittee on Space Science and Applications.

At Bell, Jay contributed to the design of the V-15 tilting prop rotor. Jay worked as a designer on Bell's Model 300 proprotor blade and on the D 212 thin tip extended chord blade. He was the principal designer of the D 270 proprotor blade and folding mechanism. He was the design engineer on the D 272 folding proprotor blade.