Tightening regulation of airport noise is set to boost interest in hush-kitting older business jets, according to Hubbard Aviation Technologies, which will demonstrate its QS3 system for Gulfstream IIs and IIIs at EBACE 2012 in Geneva next week. Earlier this year the U.S. Congress passed legislation that will ban any civil aircraft that does not meet ICAO Stage 3 noise standards after Dec. 31, 2015, and, according to the Minnesota-based company’s president, Bernie Weiss, operators of older aircraft are set to face increased pressure globally.

Based on his discussions with airport officials, Weiss believes that even operators of hush-kitted aircraft will be subject to actual measured noise levels at airports rather than being automatically exempted. In his view, this is good news for Hubbard, which so far has sold only three kits: one on a GII and the other two on GIIIs. By comparison, Hubbard’s main competitor, Quiet Technology Aerospace (not present among EBACE exhibitors) has sold close to 80 and charges $1.1 million for its system.

Weiss thinks this will change in the coming years for several reasons. Hubbard has recently reduced the price on its system and is now selling, for less than $1 million, kits that had retailed for $1.5 million, “because that’s what the market will bear.” The company also maintains that the QS3 system is quieter than the QTA technology and qualitatively superior because it includes a high-tech titanium mixing nozzle and a new cascade style thrust reverser. The QTA system maintains the factory OEM bucket style reverser, which is louder and requires more engine power to achieve the same opposite thrust, according to Hubbard.

“My competitor knows how to fly test and it got in there early,” Weiss said. “It was able to get the low-hanging fruit. Our particular product, because it does not utilize the existing thrust reverser, is considerably more expensive to make. Generally you would think that it would also sell for more, and it should. But because I am coming in where the market already knows QTA, I’ve got to come in and explain why my product is better.”

The Hubbard system was designed and certified by Stage 3 Technologies. However, that company failed before the kits could be put into production, leaving customers who had ordered it in the lurch. One of them was investor, retired broadcast magnate and Gulfstream II owner Stanley Hubbard. He acquired the intellectual property and hired Weiss to run the company and put the kits into production.

The kits themselves are manufactured by Aeroshear Aviation in Van Nuys, California. Aeroshear and ADI in Pontiac, Michigan, are currently the only two authorized installers. Weiss said the kit requires 1,000 maintenance hours to install, or about three to four weeks of downtime. Installation price is included in the kit price.

The kit has three main components: an alternating-lobe exhaust nozzle; a fuselage-mounted, acoustically lined ejector; and a cascade-style thrust reverser. “The installation on this product is not rocket science but it is detailed. A good shop can do this but they have to be shown how,” said Weiss. “The system is bolt-on. Where the work comes in is in the rear of the fuselage. We take the C-frames and make them into I-frames. We have to empty the rear equipment bay and add on these frames. We also extend the pylons because our ejector is over six feet long. It has to be in order to attenuate the sound.

“As far as the thrust reverser and the mixer are concerned, literally it is the same process as the OEMs have,” Weiss said. “We use the same mounting ring.” The system adds 380 pounds to the aircraft’s empty weight.

According to the company, the integrated system works together to produce superior results compared to the QTA system and it claims its QS3 system registers anywhere from 30 percent to 50 percent quieter in flyover, lateral and approach phases. It also reduces in-flight cabin noise from 8 to 32 percent depending on location and between 65 and 79 percent during thrust-reverser operations.

The company’s pilot, Morgan Combs, has logged several thousand hours in its own GII and, after more than 200 hours flying them, he said the QS3 kits perform as advertised.

“I’ve been flying this GII long before the hush kit was put on,” he told AIN. “What they say about them is true: they do work. The very first takeoff I made on this GII with the kit, I pushed the power up for takeoff. It sounded like you were just putting the throttles where they should be to taxi away from your parking spot. I looked down to make sure they were at takeoff power. The noise difference is very noticeable in the cockpit.”

Combs said it is quieter in the cabin, as well. “The boss and everybody who rides back there definitely notices that it is quieter [in the cabin],” he told AIN.

According to Combs, the kit means less vibration on the runway, especially during thrust-reverser activation. On a stock Gulfstream II, “the vibration you really notice is when you land and those big buckets [reversers] open. That goes away [with the QS3] and you will find that these cascade reversers are very effective. Pilots who have flown these airplanes a lot will notice that the airplane has less yaw and is more stable [on the runway],” he claimed.

Air traffic controllers also notice the difference. “Towers tells me it is as quiet as a Gulfstream IV,” reported Combs.

Weiss said the addition of the QS3, given that GIIs trade for less than $1 million and a GIII can be bought used for $1.5 million, presents an inescapable value proposition. “These airplanes perform their missions with a lot less cost than a more modern airplane,” he stated. “Mr. Hubbard used to own a GV, but eventually realized that it wasn’t worth an extra $25 million not to make a fuel stop on his way to Asia.”

While the bulk of the GII and GIII fleets remain in the U.S., Weiss said he is increasingly getting product inquiries from Gulfstream operators in the Middle East, South Africa, Mexico and South America. What remains to be seen, however, is the degree to which suppressed values for older business jets like this will dampen demand for investing in hush kits.

Hubbard Aviation Technologies has its QS3-equipped GII on the EBACE static display. En route to Geneva, the aircraft made a tour of European FBOs to promote the benefits of hush kitting.