Firefighting Fundamentals Flashcards
Purpose and duties of Firefighting:
The primary duty of the firefighter is saving lives. The secondary responsibility is to extinguish fires and limit the damage to aircraft, shipboard, airfield installed equipment, and/or airfield structures.
Fire Triangles/Tetrahedron:
The fire triangle is a simple model that includes heat, fuel, and oxygen as the key components. Research in the past 30 years has indicated the presence of a fourth critical element which is the chemical chain reaction that takes place in a fire and allows the fire to both sustain itself and grow. The addition of a fourth element is what makes the triangle become a tetrahedron. The removal of any one of the elements prevents or extinguishes a fire.
Class A Fires:
Occur in combustibles materials that produce an ash such as burning wood and wood products, cloth, textiles and fibrous materials, and paper products. Effective extinguishing agents are water (H2O) or Aqueous Film Forming Foam (AFFF).
Class B Fires:
Occur with flammable liquid substances such as gasoline, jet fuels, oil, and other petroleum based products. Effective extinguishing agents are AFFF, Halon 1211, Purple K Powder (PKP) and Carbon Dioxide (CO2).
Class C Fires:
Are energized electrical fires that are attacked by using non-conductive agents.
Effective extinguishing agents are:
1. Energized. CO2, Halon, PKP, and H2O in fog patterns with a minimum distance of 4 feet.
2. De-energized. Treat as a Class A, B, or D fire.
Class D Fires:
Combustible metals such as magnesium and titanium. Effective extinguishing agents are H2O in large quantities in high velocity fog, apply water from a safe distance or from behind shelter as small explosions can occur.
Aqueous Film Forming Foam (AFFF):
AFFF liquid concentrates consist primarily of synthetic fluorocarbon surfactant materials that are noncorrosive and have an unlimited shelf life when stored in a protected area. 6% Percent AFFF concentrate is approved for naval use.
Water (H2O):
Water is not generally considered to be a suitable agent for use in combating large aircraft fuel fires without the addition of either foam agents or surfactants. It has the ability, when properly applied, to cool the aircraft fuselage and provide a heat shield for personnel. Water is also an effective agent for cooling ordnance, batteries, and Class A fires.
Halon 1211 (Bromochlorodifluoromethane):
Intended primarily for use on Class B and C fires; however it is effective on Class A fires. Halon 1211 is a colorless, faintly sweet smelling, electrically nonconductive gas that leaves no residue to clean up. Halon 1211 extinguishes fires by inhibiting the chemical chain reaction of the combustion process.
Carbon Dioxide (CO2):
15-Pound Portable Units and 50-Pound Wheeled Extinguisher Units. These units are intended primarily for use on Class B and C fires. CO2 is a colorless, odorless gas that is approximately one and one-half times heavier than air. Fire suppression is accomplished by the displacement of oxygen to below the level that is required to support combustion.
Potassium Bicarbonate (Purple-K-Powder or PKP):
PKP is intended primarily for use on Class B fires. The principal chemical in PKP is potassium bicarbonate and the dry chemical extinguishes the flame by breaking the combustion chain. It does not have cooling capabilities, therefore it will not result in permanent extinguishing (reflash protection) if ignition sources are present.
