Fly Quiet Worldwide




The QTA Plus Hush Kit enables the GII, GIIB and GIII aircraft to operate world wide, even meeting the more stringent “Marginal Compliance’ noise regulations enacted by Europe and Australia.

The Marginal Compliance regulations require that the aircraft meet the FAA Stage 3/ICAO Chapter 3 noise levels and be at least 5dB quieter than these regulations. This quieter noise standard is a requirement at many noise sensitive EU airports, for operation in Switzerland and Austria after 7pm and on weekends. Australia requires all Part 25 certified aircraft to meet the -5dB, ‘Marginal Compliance’ regulation.

The QTA plus Stage 3 hush kit is the only solution that meets these stringent requirements and enables the aircraft to operate world wide, basically any where you can operate a GIV, a QTA equipped GIII can operate. (the only exception being Farnborough, England which is a Stage 4 only airport).



The QTA Hush Kit uses a unique translating mechanism to enable integration of the acoustic system with the existing thrust reversers, requiring no additional controls. The ejector is mounted on two carriage assemblies, one on each side, and slides on low-friction linear bearings.

The ejector is mechanically linked to the Thrust Reverser System, such that when it is deployed, two “translating” links push the ejector aft and the thrust reversers’ doors deploy. Upon stowing the thrust reversers, the ejector is automatically pulled forward into the stow position.

Forward radiated fan noise is a contributor to both take off and approach noise levels. It is also the largest contributor to cabin noise. The high-pitched whine of the Spey engine is tamed by the QTA Hush Kit, which incorporates acoustic treatment to the Inlet Bullet to reduce the sound level of the fan.


The QTA Hush Kit retains the original GulfstreamTM acoustically treated tailpipe, the original 5 lobe mixer nozzle is removed and replaced with a 12 lobe “fluted” mixer nozzle. The 12 lobe nozzle works with the ejector in promoting the mixing of the ambient air stream with the jet exhaust. The major reduction in outside aircraft noise levels is achieved through this mixing.



The QTA Hush Kit has been designed to provide the required noise reduction of 7 dB, while maintaining optimum performance across the flight envelope.

Take Off

Extensive testing of the Gulfstream aircraft in Stage 2 and Stage 3 configurations, at all flap settings, showed there is no change to climb performance with the QTA Kit installed.

Range Performance

Current data reported by operators has shown there to be “NO CHANGE” in range of the QTA Equipped aircraft. On short flights of 2 hrs or less a small increase in fuel burn of less than 1% has been reported.

The QTA equipped aircraft can fly any city pair that a Stage 2 aircraft can.

The Hush Kit’s configuration is optimized for best performance in the speed range of 0.77 and 0.8 Mach.




A welcomed benefit of the QTA Hush Kit is the significant reduction in cabin noise levels. QTA has conducted before and after in flight noise tests to quantify the benefit.

Results will vary aircraft to aircraft depending upon the standard of cabin noise suppression insulation installed.

Two examples are shown, one is of a GIII already equipped with the Flight Environments advanced noise suppression system installed and the second is of a GII with the original factory insulation.


Noise measurements were taken with the Cabin to Cockpit door closed and the aft door to the rest room closed. Measurements were taken at 40,000 ft in cruise at Mach .80. Noise levels are in dB SIL (Speech Interference Level).



With a simple mechanical system, the QTA kit requires just periodic cleaning of the ejector translating rails greasing of the bearings, and visual inspection during A,B and C check. All inspections are dovetailed to fit within the aircraft’s existing maintenance schedule.

The QTA Stage 3 Hush Kit allows complete access to all engine systems, creating no change in normal maintenance procedures. With minimal addition of parts, and no change to the aircraft engines, the QTA Hush Kit will not effect any warranty on engine overhaul.





The QTA Stage 3 Hush Kit allows complete access to all engine systems, creating no change in procedures.



The simple design of the QTA Hush Kit allows us to guarantee the installation on your aircraft, in 10 days or less.

Installations can be carried out at QTA’s Florida facilities, or anywhere you specify, worldwide, including Gulfstream Service Centers.

The QTA Hush Kit exclusive design uses your plane’s original reversers, is light weight, has minimum parts and can be installed quickly, sometimes in as little as seven days!