GRE Technology Moves South
Noisy open field run-ups have come to an end at the Bogotá International Airport with the completion of the first ground run-up enclosure in South America.
The three-sided enclosure, designed and built by Blast Deflectors of Reno, Nevada (US) was constructed as part of the new maintenance area on the west end of the airport.
The facility, which was completed by BDI earlier this year, provides a safe and convenient location for ground run-ups while minimising the acoustic impact on the nearby communities of Funza and Fontibón.
The Colombian Environmental Ministry passed resolution 627 in April 2006, creating stringent day and night time noise regulations for the airport. Open field engine tests conducted at the Bogotá International Airport produced noise levels over 90 decibels, far surpassing the limits stipulated by the environmental resolution. In order to address this issue, the operator of the airport, OPAIN, contracted the services of BDI.
BDI has specialised in the design and construction of jet blast deflectors (JBD) and ground run-up enclosures (GRE) for over 50 years. The most common GRE is a three-sided, open-top facility that reduces noise levels generated during high power engine runs. Historically at BOG, open-air run-ups were performed at the end of runway 13R, not far from the eventual GRE location. “The facility is intended to benefit the surrounding communities by minimising the acoustic impact of ground tests,” says Don Bergin, director of technical sales for BDI.
BDI was actively involved in the early stages of the project and performed an analysis of the area that included a study of the historical winds in order to identify the optimal facility orientation. The orientation of a GRE is critical in order to ensure both the maximum usability and best acoustic performance. BDI was the general contractor on the project and worked closely with OPAIN to resolve potential issues prior to commencing construction.
“Working as a general contractor created both logistical and cultural challenges for us,” says Don Cipriano, project manager for BDI. “Our facilities are prefabricated to eliminate any site cutting and welding to reduce installation time. This required us to coordinate heavily with OPAIN and Colombian government agencies,” say Cipriano. The Bogotá GRE was completed in record time, with a total construction duration of four months, which was a requirement by Aerocivil, the national aviation authority of Colombia.
One of the most important factors when designing and building a ground run-up enclosure is aerodynamic stability. “BDI’s solution is our patented design known as the Stabile Flow™ GRE which incorporates acoustically treated vented side walls and other aerodynamic features that provide smooth, turbulent-free airflow to the engines. This technology allows maximum usability even in challenging cross-wind and tail-wind conditions,” says Bergin.
“The objective is to make the facility as usable as possible. If a GRE is built without consideration of aerodynamic factors, it may perform well acoustically, but if the aircraft needs to be pulled out of the facility in order to perform a run-up due to aerodynamic limitations the acoustic benefits of the facility are negated.”
BDI has constructed more than 15 Stabile Flow™ facilities around the world, making them a leading supplier of ground run-up enclosures. “All of BDI’s facilities have achieved usability at or above specified levels,” adds Bergin.
Not only do BDI installations provide outstanding usability and aerodynamic performance, but they also incorporate the company’s patented Noise Blotter™ acoustic panels.
“The Bogotá facility is lined with over 2,800 of our patented Noise Blotter™ acoustic panels,” say Bergin. These panels are specifically designed to absorb the low frequency engine noise of aircraft engines, a requirement to ensure that engine run-ups do not exceed the noise levels specified by Colombian environmental regulations.
The Bogotá GRE was tested with an Avianca A330 and surpassed the specified noise attenuation required by OPAIN and Aerocivil. The facility is fully operational and the airport recently passed a resolution requiring all run-ups to be conducted inside the facility.