In modern military and commercial aviation, fuel tank ullage—the empty volume above liquid fuel—contains flammable hydrocarbon vapors that pose severe explosion hazards if exposed to electrical arcing or static discharge. While mechanical flame arrestors and reinforced bladders mitigate certain localized risks, onboard inert gas generation systems (OBIGGS) remain the primary defense against fuel tank ignition by continuously displacing oxygen with nitrogen-enriched air. These systems utilize permeable hollow-fiber membranes to separate and vent oxygen molecules from pressurized bleed air, driving ullage oxygen concentrations below nine percent by volume. Consequently, establishing an inert atmosphere through active nitrogen displacement prevents catastrophic vapor detonation under varying flight altitudes and operational temperatures.
Which of the following statements most accurately expresses the main idea explicitly stated in the passage?
- APermeable hollow-fiber separation membranes strip oxygen molecules from bleed air to maintain tank oxygen levels below nine percent.
- BAviation safety mandates eliminating all flammable hydrocarbon vapors across every internal aircraft compartment.
- Onboard inert gas generation systems serve as the principal protection against fuel tank ignition by displacing oxygen with nitrogen.Cevap
- DMechanical flame arrestors and reinforced bladders provide the primary line of defense against fuel vapor detonations.