Published June 29, 2021
On 23 February 2009 the Government issued Decree 20/2009/ND-CP on managing the height of aviation obstacles and airspace management and protection sites in Vietnam.
Any object more than 45 m above natural ground level that may affect flight safety, such as telecom masts, high-voltage pylons, factory chimneys and tall buildings, counts as an aviation obstacle and must carry aviation obstruction warnings.
Obstruction warnings mean painting markings and installing warning lights, or placing markers and flags, on the obstacle so that pilots in flight can see them from a safe distance in every direction.
Aviation obstruction warnings are set out in Appendix IV: Aviation obstruction warnings. These rules are fully consistent with the International Civil Aviation Organization's ICAO Annex 14.
