Comparative Evaluation of Rescue Saw Blades for Forcible Entry Into Advanced Composite Material Aircraft

New aircraft designs use significant quantities of advanced composite materials, which presents a new challenge to aircraft rescue and firefighting personnel: how to safely cut into composite materials when responding to incidents involving these aircraft. This report provides guidance regarding forcible entry on aircraft that are composed of mostly advanced composite materials using a circular saw.

A cutting test apparatus and procedure were developed to measure the force exerted by a saw blade on a panel made with aircraft-grade, advanced composite materials, as well as measuring blade wear and particulate production caused by this type of cutting. Tests were conducted to compare the performances of three different types of saw blades: metal, concrete, and diamond-tipped. Each saw blade was tested by cutting panels of various thicknesses of aluminum, GLAss-REinforced aluminum laminate (GLARE), and carbon fiber-reinforced plastic (CFRP). These tests examined saw blade cutting performance in both dry and wet cutting conditions.

When comparing the force measurements from all the panels and saw blades, the diamond-tipped saw blades cut through both the GLARE and CFRP panels easier than the aluminum panels. Under wet cutting conditions, the metal and concrete saw blades had the highest forces for all three materials. Mass and diameter loss were more apparent during the dry cuts than the wet cuts. Of the three saw blades, the concrete saw blades had the most mass and diameter loss. Particulate analysis showed that the diamond-tipped saw blades released the smallest amount of particulates of all three saw blades.

Overall, the diamond-tipped saw blade exerted the least amount of force, had the least wear, and released the least amount of particulates, thereby concluding it to be the best choice of the three saw blade types for use on composites.

DOT/FAA/TC-15/26
Authors: Jonathan Torres and William Doig