NBAA Convention News

Stage III hush kits revived

 - September 30, 2008, 10:02 AM

Hush kits developed by Stage III Technologies for Rolls-Royce Spey-powered Gulfstreams are back. Here at NBAA’08, the new owner of the design, Hush Kit Aviation, LLC, is exhibiting the first installation of an FAA-certified, Stage III hush kit on a Gulfstream II in the static park at Orlando Executive Airport.

Noise requirements at many airports around the world prohibit or restrict the use of aircraft, such as the original Gulfstream IIs and IIIs, that are qualified to no better than the Stage 2 noise-level standard. The addition of engine hush kits to such aircraft can qualify them to operate at airports that require meeting Stage 3 noise-level limits.

Stage III Technologies, formerly of La Jolla, Calif., ceased operations on February 8 this year after running out of money and lacking an airplane to use as a sales vehicle, according to Todd Stimmel, former president and CEO. The company’s assets included one hush kit, the FAA supplemental type certificate (STC) and three patents. The first four hush kits, priced at $1.1 million, were scheduled for installation in March, July, August and September.

Said an observer at the time, “I would hope that perhaps somebody could see this as an opportunity to get into [the Gulfstream hush-kit business] at a reasonable price and move forward. I think that people would be disappointed not to see any competition.”

In stepped Stanley Hubbard, chairman, CEO and president of Hubbard Broadcasting Inc. in Minneapolis and the owner of a GII (N20H) since 1969. Hubbard had been an investor in Stage III and had loaned N20H to the company for testing in the 1990s.

“We [an affiliate of Hubbard Broadcasting] did not buy the company, Stage III Technologies,” Hubbard told NBAA Convention News. “We bought the STC and the patents. Hubbard Broadcasting had already purchased the first hush kit, and finished the manufacturing and assembly of it after Stage III ceased operations. Now we are in the process of setting up a corporate structure to produce the hush kit.”

N20H, which is also equipped with Aviation Partners winglets, is the GII that Hush Kit Aviation has on static display here. Western Jet Aviation, a long-time Gulfstream maintenance center at Van Nuys Airport in California installed the hush kits on the airplane over a period of eight weeks. Stimmel said normal installation should take about five weeks.

Hubbard confirmed that Stage III was undercapitalized. “The company never got a certified, production hush kit on an airplane,” he said, but he is a strong advocate of the design. He hired Stimmel, now vice president of Hush Kit Aviation, and charged him with setting up the company, selecting suppliers and producing the hush kits.

The Hush Kit Aviation (formerly Stage III) hush kit contains no moving parts and includes a 10-lobe mixer nozzle coupled with an acoustically lined ejector and cascade-style thrust reversers, which replace the original clamshell thrust reversers
on the Speys. Stage III Technologies received FAA certification for installation of the kits on the Gulfstream II, IIB and III in May 2005. Development had taken nearly six years, and this STC is now in the process of being transferred to Hush Kit Aviation.

At that time it received the STC, Stage III Technologies reported that its hush kit reduces overall takeoff noise levels to 70- to 73-dBA (depending on aircraft model) and to 86 dBA on approach. The company had sought orders for installations to begin in the summer of 2005. The first four kits were then priced at $1.5 million and subsequent orders booked before July 1, 2005, were priced at $1.795 million, after which the full retail price of $2 million would apply.

Hubbard said additional research on the cost of production and installation is required before he can set a price on the hush kit. He said he expects the initial production rate will be one per month, although demand may dictate that this be increased.

Other Gulfstream Hush Kits

When Stage III Technologies shut its doors earlier this year, just one company– Miami-based Quiet Technology Aerospace (Booth No. 785)–was left to provide Stage 3 hush kits for the 400-strong Gulfstream II and III market.

Since it received its STC in January 2003, Quiet Technology Aerospace has installed its translating-ejector hush kits on more than 70 Gulfstream GIIs, GIIBs and GIIIs and has two in the pipeline, according to Ben Brown of Quiet Technology. The price of QTA’s hush kit is $1.25 million.

Really Quiet of Mojave, Calif., was the first company to receive an STC (in 2002) for a Stage 3 hush kit for Gulfstreams. It never made any post-certification installations and shut down in 2004.