Quiet Technology Aerospace has received FAA STC approval of its carbon-graphite inlet upgrade for the Gulfstream G200’s Pratt & Whitney Canada PW306A engines. The retrofit, which also received FAA STC approval last fall for the PW305-powered Bombardier Learjet 60, provides a solution to corrosion issues with the original aluminum honeycomb inner acoustic barrels in PW300-series engines.

According to Hollywood, Fla.-based QTA, a combination of materials and environmental effects—namely, rain and pollutants—causes corrosion and delamination in the bottom of the inner barrel. Even when not delaminated, the acoustic face sheet can become unbonded due to surface corrosion. Either defect requires replacement of the entire inner barrel with new parts. QTA said its design retains all of the other component parts of the nose cowl, replacing just the inner barrel to eliminate the corrosion problems.

Since receiving the STC for the Learjet 60 model late last year, QTA has ramped up manufacturing and production levels to satisfy market demand for its inlet upgrade program. There are more than 250 G200s and more than 400 Learjet 60/60XRs in service.

According to the company, there has been a strong response to its carbon-graphite inlet upgrade program for the Learjet 60. As of early this month, inlets in 19 Learjet 60s have been upgraded and placed in service. “Operators are both relieved of the corrosion problem that has plagued their inlets and impressed with the quality and simple, reasonably priced solution,” QTA said.

Meanwhile, QTA has implemented a low-cost inlet loaner and exchange program that prevents extended AOG conditions. The first set of loaner inlets became available this month.

“Our engineering and manufacturing team has worked very hard to bring this terminating solution and exchange program to affected G200 operators,” noted Martin Gardner, QTA’s vice president of engineering and customer support. “Aside from the permanent fix our graphite-composite inlets offer, we have throttled up our production. We currently have a production lead time not to exceed one month.”

The company is currently working on a similar STC for the PW305-powered Hawker 1000. Its carbon-graphite inner barrels come with a lifetime structural warranty.

QTA also holds 11 STCs for hush kits on airliners, military transports and business jets, the latter group including noise-reduction solutions for the Gulfstream III and Learjet 60. In addition, its FAA Part 145 aircraft repair station in South Florida provides support for composite and structural repairs, including GIV winglet attachment rework.