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The upcoming Part 36 noise restrictions placed on all Stage 2 aircraft by the FAA and EASA due to take effect on Jan 1st, 2016, will render all G11 and G111 aircraft un-flyable in the US, Canada, and most of the countries in Europe. This is a sad state of affairs, especially as these aircraft have been flying under the 75,000 LB GTW exemption for years. Coupled with this announcement, the operators of these aircraft saw an immediate drop in the value of their aircraft.

The options available to make these aircraft Stage 3 compliant are offered by two noise suppression companies, Quiet Technology Aerospace in Opa-Locka, Florida, and Hubbard Aviation Technologies in St Paul, Minnesota. The Quiet Technology system is called the QTA and the Hubbard Aviation Technologies system is called the QS3. The question for those operators wishing to keep their aircraft is which one of these hush-kits do I buy? Hopefully this article can aid in that decision making progress. Jet Consultations is available for further guidance on this topic, and may be contacted at This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Quiet Technology was able to get the QTA to the market place first and have had success selling over seventy five kits. Unfortunately, Hubbard Technologies was late in comparison and did not get final authority for their Supplemental Type Certification till late November 2008. The current economic recession has impacted their ability to make sales. Hopefully for both companies, the FAA announcement in February 2012 has already prompted operators to start evaluating the two systems. As the deadline approaches, more customers should materialize for both companies and there should be plenty of available business. The key for logistical planning is to schedule the installation sooner rather than later. Operators should look at this as an opportunity to enhance the resale value of their aircraft.

The three areas the FAA uses to evaluate Part 36 noise are approach, sideline, and flyover. The Hubbard QS3 is well designed. It is more than 30% quieter on the exterior than the QTA. It is also significantly quieter in the cabin during cruise flight and 70% quieter during landing when the reversers are deployed. The Rolls Royce Spey engine, which both the G111 and G11 utilize, was originally designed for the BAC 1-11 using cascade style thrust reversers. Hubbard has incorporated that design into the QS3 system. This allows for less engine power to accomplish the same reverse stopping force as the QTA. The added benefit of this design is that there is less wear and tear on the engine and structural vibration on the empennage.

During translation to reverse thrust, the QTA ejector slides down a carriageway to allow the clamshell doors to deploy, and is not aesthetically pleasing to see. This movement does require periodic inspections of the carriageway and associated linkage. These inspections can be easily coordinated with regularly scheduled maintenance. There is no movement with the QS3 ejector.

The QTA system is easier to install and the average time to finish the installation is approximately 10 days. The QTA team of experts is available to travel to wherever your aircraft is located. In contrast, the QS3 installation can be accomplished at any FAR 145 repair station or at Hubbards Van Nuys California facility and takes approximately 30 days. The QS3 installation represents a significant down time and is more inconvenient in comparison to the QTA. Operators who select the QS3 should try to schedule their installation during regularly scheduled heavy maintenance to minimize the negative effects of the down time.

The pricing for these two systems is representative of the research, development and completed product package that both companies have invested in time, manpower, and equipment. The QS3 is approximately 20-25% more expensive than the QTA. This additional cost is reflected in the new QS3 thrust reverser system. There are no overhaul requirements for the QS3 reversers, just on condition visual inspections. This represents a substantial savings in inspection and overhaul costs over the QTA system over time. In the opinion of Jet Consultations, the QS3 is the system to choose. The overall design is more static as far as the ejector is concerned, and the reverser cascade system is more efficient. In addition, the QS3 has an overall much quieter noise footprint.

The QTA serves its purpose, it meets the necessary Part 36 noise standards and is less expensive to install. There were some early teething troubles related to the carriageway that the ejector slides down and associated linkage, and this required a redesign. These problems were resolved, and over the last two years QTA reports no major in service problems. Jet Consultations recommends that operators considering these two systems should review the applicable web-site for more in depth information. The sales people at both organizations are very pleasant and easy to speak with. For further unbiased counsel please do not hesitate to contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Jet Consultation offers Private Plane Acquisition, Private Jet Acquisition, Corporate Aircraft Acquisition and Flight Department Management services for high net worth individuals, private and public sector corporations.