Frangibility of Approach Lighting Structures at Airports

You are here: Homepage > Search

Frangibility of Approach Lighting Structures at Airports

J. F. M. Wiggenraad / D. G. Zimcik

Aircraft operations at airports require the presence of various types of equipment, such as approach lights, wind direction indicators, instrument landing systems (ILS), or microwave landing systems (MLS). Some of these installations must be positioned close to the runways. Furthermore, these installations quite often need to be pointed in a specific direction within very narrow tolerances, even during severe weather circumstances. Therefore, their construction and their support must be stiff. However, should aircraft stray into these installations during landing or take-off, these same installations become obstacles to flight safety. Since the resistance of these 'obstacles' may well determine the outcome of such a mishap, it must be minimal. In this respect, the damage which occurred in 1972, when a Boeing 747 made an incorrect take-off, and subsequently struck the approach lighting system is described. The aircraft lost two of its main landing gears, and parts of the approach light supporting structure had pierced the aircraft, endangering the flight safety considerably.