Conforming GII/III hush kit in the air

 - April 16, 2008, 5:42 AM

Miami-based Quiet Technology Aerospace is nearing completion of about 45 hr of planned flight testing of its first FAA-conforming Stage 3 hush kit for Gulfstream IIs and IIIs. Flight testing of a GII equipped with the company’s translating-ejector type hush kit started in late May and follows 30 hr of baseline flight testing of the aircraft without the hush kit installed.

Director of engineering Martin Gardner said preliminary flight-test data revealed “no measurable difference in climb or cruise performance.” The flights are being conducted from Opa Locka, Fla., and Roswell, N.M., where the noise certification is being done.

Quiet Technology’s kit, which uses the airplane’s existing thrust reverser, is similar to the one already certified on the BAC 1-11, which also uses the Rolls-Royce Spey engine. “The hush kit adds about 220 pounds, with no reduction in cruise speed,” according to Gardner. “We expect the fuel burn of hush-kitted GIIs to increase by about 3 to 4 percent over non-hush-kitted GIIs, based on our experience with the hush kit on the BAC 1-11.”

Price for the kit is $1.5 million, and Gardner said customers to date have placed deposits for eight kits. Deliveries will begin immediately upon receipt of the STC, now scheduled for next month. “After the award of the STC the price will be reevaluated upwards to somewhere in the region of $1.7 million.”

For some time three companies have been competing to develop a practical hush kit for the GII/III, but only one–Really Quiet–has an STC, awarded in January. The Really Quiet kit also incorporates a translating ejector that is in the aft position while in the takeoff or approach configuration. Once the aircraft transitions out of the landing or approach configuration the ejector shroud slides forward. The Really Quiet system also requires a redesigned thrust reverser. A “product improvement” mod is being developed to address a range penalty of up to 5 percent. Installed price is $1.95 million at the company’s Mojave, Calif. facility.

Meanwhile, Stage III Technologies of La Jolla, Calif., has suffered a setback to its testing program, anticipated to have been completed this summer. The flight-test aircraft was operated by Tyler (Texas) Jet’s sales and brokerage division, now in Chapter 11 bankruptcy. According to Stage III’s Ken Seeley, the aircraft, which had been loaned to Stage III for the flight-test program, has been grounded as part of the bankruptcy court action. The program had approximately five hours of flutter testing left, said Seeley. “Now we have to find another aircraft and start from scratch,” Seeley told AIN. He added that the test program would take approximately two months from the time a new aircraft is secured.