For Learjet 20-series operators, Dec. 31, 2015, has been looking like a dark day. That’s the last day aircraft with takeoff weight of less than 75,000 pounds will be allowed to operate in the contiguous U.S. if they do not meet Stage 3 noise standards. But Trine Aerospace (Booth 4492) has a solution that does not involve selling offshore or parting out airplanes.

Based in Colorado Springs, Colo., Trine has developed a Stage 3 hushkit for Learjet 20-series models, starting with the 24/25 series, but expected to be available for all 300 or so 20-series aircraft currently in the fleet. The kit costs about $75,000 and takes three days to install. It is expected to be approved early next year.

The best part about the Trine hushkit, said company chairman Roy Clennan, is that it does not require removing the aircraft’s thrust reversers. The hardware changes involve only the cowlings and exhaust nozzles. “About two thirds of these aircraft have been outfitted with reversers,” said Clennan, “and we wanted to design a solution that allows owners to keep them. Competing kits require owners to remove their thrust reversers.”

Trine operates its own Learjet 24D, strong motivation to come up with a solution to the FAA Reform and Modernization Act requirement. Clennan said, “It is impossible to replace what this jet will do for the money, and current owners are not interested in simply scrapping their aircraft or selling them out of country. We saw an opportunity to offer our engineering and manufacturing experience to keep the aircraft flying, and we are able to manage the certification in-house. It just makes sense.”

Earlier this year, Trine received its FAA Part 145 repair station certificate. The company also offers engineering, manufacturing and modifications on general aviation, commercial and special-missions aircraft. Trine also specializes in avionics installation and repair.