Obstacle analyses

Obstacle assessments are targeted to analyse if natural and man-made obstacles around an aerodrome meet the requirements defined by law. This includes Obstacle Limitation Surfaces and Obstacle Assessment Surfaces (OAS), which define areas that shall be kept free of obstacles. The assessment of these surfaces is usually required when construction projects in vicinity to an airport’s runway are considered. For a widespread evaluation of the obstacle backdrop the relative position and height of the obstacle to the aerodrome is analysed. This is based on the following laws and regulations:

  • Obstacle Limitation Surfaces according to ICAO Annex 14, EASA CS-ADR-DSN and Germany’s BMVBS obstacle regulation (NfL I 328/01)
  • Limitations according to ICAO PANS-OPS Doc 8168, including OAS and determination of Obstacle Clearance Altitude/ Height (OCA/H)
  • BMVBS all-weather regulation (NfL I 1/99), also based on ICAO Annex 14

If the analysis reveals violations of these surfaces, an additional safety assessment (see Aeronautical Studies) according to ICAO regulations will prepare the project to be ready for official approval.