Breeze Airways E-190 Practice Exam

Oxygen flow duration is fixed by the system design and is set to provide a known, safe amount of time after masks deploy. For the E-190, that duration is about 12 minutes. This ensures there’s enough oxygen for everyone on board while the aircraft descends to a safe cruising altitude and crews manage the situation. The capacity of the onboard oxygen supply and the regulators are chosen to sustain the required flow for roughly 12 minutes per passenger mask. Numbers like 6, 8, or 10 minutes aren’t aligned with the system’s design and would not guarantee the same safe duration for all passengers.