Olsson Associates has been providing engineering services for the Thomas County Airport since 2006. Projects have included design of a major grading project to remove hills that were too close to the runway; widening, extending and lighting the runway; and seal coat application on all airport surfaces. Olsson also provided full-time, on-site construction observation for all the projects.
Surface Seal Coat
In 2014, a surface seal coat was applied to all airport surfaces. Olsson recommended Thermoplastic Coal Tar Emulsion with Aggregate (Micro-Surfacing), per Federal Aviation Administration (FAA) Specification P-629. This application provided a heavy duty seal and longer life for the asphalt surfaces.
The project also included full-depth repair of some pavement cracks and re-sealing of other cracks. Because the airport has only one runway, Olsson’s specifications included a tight schedule and the project was completed in only 19 working days.
Runway Extension and Widening
Beginning in 2006, Olsson Associates designed a 2-phase project to extend and widen the runway. The project was phased to match the availability of FAA grant funds.
Phase I: In the first phase, 350,000 cubic yards of soil were re-graded for a runway safety area (RSA) and runway object free area (ROFA). Obstructions were also removed. The excess dirt from the re-grading was used to shape a future parallel taxiway and a building area for future hangars.
Phase II: In the second phase, Olsson designed the project to widen, extend, and add new lights to the asphalt runway, which was completed in 2008. The widening was done on one side only, shifting the centerline by five feet. The shift required removing and replacing all of the pavement markings.
The existing asphalt surface was very dark because of a recent seal coat. The airport was concerned that, from the air, the removal areas might appear much lighter than the seal coated pavement, leading to potential pilot confusion. To address this concern, Olsson recommended a new seal coat to cover the paint removal and to extend the pavement life. Although not originally programmed, the FAA agreed to fund this additional work based on Olsson’s justification.