Development of an Intermediate-Scale Test Method for Evaluating the Effectiveness of Firefighting Agents to Suppress Aircraft Skin Composite Fires

This report describes the research effort conducted to characterize the flammability and suppressibility of aircraft skin composite materials and potential surrogates. The main objective was to develop an intermediate-scale test method to quantify the burning characteristics of composite materials and the required amount of agent needed to suppress burning aircraft skin composites. The aircraft composite materials evaluated during this research effort included carbon fiber-reinforced polymer and glass reinforced aluminum. Surrogate materials included wooden oriented strand board, glass fiber-reinforced polymer, and Garolite.

Assessment of the flammability and suppressibility of these materials involved a series of four progressive tests. The first test series was representative of an intact aircraft fuselage exposed to a fuel pool fire below the aircraft and assessed the ignitability of a vertical panel when exposed to a fire. The remainder of the test series characterized the burning of the composite materials with complex geometries that simulated conditions expected in postimpact crash scenarios. The final test series exposed parallel plate composite cribs to pool fires to determine both the comparative burning characteristics of the composite and surrogate materials and the additional amount of suppression agent required to control and extinguish the composite fires.

As a result of this research effort, a draft test method was developed for comparatively assessing the burning characteristics and suppression requirements of composite materials using these tests as a framework. The draft test method is provided as an appendix to this report.

DOT/FAA/TC-15/31
Authors: Joshua B. Dinaburg, Christopher L. Mealy, Joseph L. Scheffey, and Gerard G. Back