Which class is defined by the ability to completely confine a fire without endangering the aircraft and occupants, with control ventilation and consideration of heat impact on adjacent compartments?

• A. Class B
• B. Class D
• C. Class C
• D. Class E

Answer: (B)

Fire containment and ventilation control within aircraft compartments determine how safely a fire can be confined inside a space without endangering the aircraft or its occupants. The scenario described—complete confinement of the fire in a single compartment, with ventilation actively controlled to prevent smoke and heat from spreading and with heat transfer to adjacent spaces limited by fire-rated barriers—fits Class D in this material. It relies on robust compartmentation, sealed doors, and ventilation dampers that can be closed to stop air flow, keeping heat and smoke from reaching other areas and protecting occupants. This level of control emphasizes keeping the fire contained and protecting the rest of the aircraft, rather than allowing spread or requiring more aggressive, widespread suppression.