Abstract

A series of fire tests were performed at the FAA William J Hughes Technical Center using various 40-gallons-per-minute hand line nozzle configurations fighting a 30-foot-diameter Jet-A fire. The objective of this test series was to evaluate fluorine-free foam (F3) on a larger scale than the standard MilSpec and International Civil Aviation Organization (ICAO) tests to determine the effects different foam delivery technologies have on foam generation, performance, and dry chemical agent compatibility.

All foams were able to extinguish all fires in all test conditions. Changes in firefighting performance due to changes in foam delivery configurations were not consistent across the different foams tested. F3s generally saw slightly increased performance with the higher expansion ratio discharges like the foam tube and Compressed Air Foam System (CAFS) discharges. The dry chemical discharge reduced extinguishment performance for two of the three F3s tested.

Foam blankets were improved with the use of a foam tube or CAFS but were severely degraded when using additional dry chemical injected into the foam stream. This is also reflected in the different foam expansion ratios observed. In all tests, the agent application ended with the extinguishment of the fire and generally foam blankets were not fully formed in the pan. If foam was discharged for a time after extinguishment, better fuel coverage and a more stable foam blanket might have been achieved. The lack of an established foam blanket in the dry chemical discharges suggests that the addition of dry chemical into the foam stream negatively affects the ability for the foam to form a blanket.