Why do obstacles need to be illuminated?

The law stipulates that buildings of a specific height and in the vicinity of airports as well as factory chimneys, towers, masts etc. must be equipped with obstruction lights.
This special lighting makes obstacles visible for pilots in the dark or when visibility is poor. Obstruction lighting is one of the most important aspects of flight safety.

What directives and regulations are there?

In Germany the Ministry for Transport and Construction Development (BMVBS) issues the regulations covering obstruction lighting on buildings. The ICAO regulations regarding the methods of marking and lighting aviation obstacles can be found in ICAO Annex 14.

• "Low intensity obstacle beacon type A": a red permanent night-time warning beacon for fixed obstructions with a brightness of 10 cd.
• "Low intensity obstacle beacon type B": a red permanent night-time warning beacon for fixed obstructions with a brightness of 32 cd.