Abstract: A lightweight armor system for defense against a high explosive incendiary rojectile characterized by a lightweight armor trigger plate placed in front of and spaced from a relatively heavier main armor. The trigger plate may consist of a ceramic-fiberglass sandwich and the main armor a one half inch thickness of aluminum backed by a built-up layer of ballistic nylon webbing and sealed by a layer of rubber sheeting. The space between the trigger plate and the main armor may be filled with a material having flame suppressive characteristics to lessen the incendiary effect of the projectile.