Development of buildings, use of tall construction machineries such as cranes and ship crossing can potentially affect safety of air navigation either due to the close proximity between the structure and an overflying aircraft, or the structure may cause an obstruction along the flight path. As such, prior clearance needs to be sought from CAAS before interested parties carry out such activities. Applicants would be able to apply here for the following Obstruction Control activities:

  • Erection of Cranes and Tall Construction Machineries

  • Ship Crossing

Please note that with effect from 17 January 2020, the Obstacle Clearance and Aerial Activities e-services are now available on Gobusiness. Please click here to access the e-services.

For enquiries, applicants can email their requests to