As project directors of Infrastructure New South Wales (INSW) Archerfield Partners engaged Aviation Projects to assess the potential impact of a proposed high voltage power line on the obstacle limitation surfaces of Clarence Valley Regional Airport, Grafton, New South Wales.

The new Grafton Correctional Centre project is being delivered by the NSW Government in partnership with the Northern Pathways Consortium. The centre will feature state of the art security and surveillance and will accommodate 1,700 inmates. The project will inject $560 million into the local economy and provide up to 1,100 construction jobs.

The project incorporates the construction of a high voltage power line to the centre. The power line corridor lies approximately 2.2 km north of Clarence Valley Regional Airport from the runway 18 threshold.

Aviation Projects conducted a detailed aeronautical analysis in support of the development application. The analysis included the validation of Clarence Valley Regional Airport obstacle limitation surfaces. Clarence Valley Regional Airport is a certified, Code 3 non-precision instrument runway airport. For a Code 3 airport the following obstacle limitation surfaces need to be considered:

  • Conical;
  • Inner horizontal;
  • Approach; and
  • Transitional.

Following the validation of the obstacle survey data and a high-level evaluation of the proposed power line, Aviation Projects found that several poles along the power line route would penetrate the inner horizontal surface. The recommendation was  to reduce the height of these poles to provide safe flight operations at Clarence Valley Regional Airport. This advice has enabled the project to proceed without detriment to aviation safety.

Clarence Valley Regional Airport Aeronautical Assessment