What should be done with the OBOGS supply lever when physiological symptoms are present?

What should be done with the OBOGS supply lever when physiological symptoms are present?

• A. ON (Both)
• B. OFF (Left)
• C. OFF (Right)
• D. OFF (Both)

Answer: (D)

When you have physiological symptoms, cut off the OBOGS entirely by turning the supply on both sides to OFF. This stops any potentially malfunctioning or contaminated OBOGS from delivering oxygen, eliminating a suspect source. Once the OBOGS is off, rely on the emergency oxygen system to restore a reliable oxygen flow to the mask and descend to a safe altitude.

When you have physiological symptoms, cut off the OBOGS entirely by turning the supply on both sides to OFF. This stops any potentially malfunctioning or contaminated OBOGS from delivering oxygen, eliminating a suspect source. Once the OBOGS is off, rely on the emergency oxygen system to restore a reliable oxygen flow to the mask and descend to a safe altitude.