(17) in this article is in "Impact simulation of a frangible approach light structure by an aircraft wing section". With the evolution of numerical methods suitable for impact analysis, a Chapter 6 was added to the Aerodrome Design Manual part 6, dedicated to "numerical simulation methods for evaluating frangibility". It states that numerical methods can be used to evaluate the frangibility of structures, but that the analytical models should still be verified through a series of representative field tests. Of all equipment or installations at airports required for air navigation purposes, ICAO has not yet formulated frangibility criteria for the tower structure supporting the ILS glide path antenna, "considering its unique nature", basically: its size. A first publication on this subject is given in "Frangible design of instrument landing system/glide slope towers". Glass Tempered glass is said to be frangible when it fractures and breaks into many small pieces. Other Some security tapes and labels are intentionally weak or have brittle components. The intent is to deter tampering by making it almost impossible to remove intact. See also Friability Sacrificial part Spall References Ammunition Fracture mechanics