The flight crew oxygen cylinder is at normal pressure, but oxygen downstream of the pressure-reducing regulator rises above 100 pounds per square inch gauge. What protection is provided?, The regulator relief valve opens and releases oxygen into the adjacent area., The cylinder frangible disk ruptures and vents the entire cylinder overboard., The pressure transducer commands the cylinder shutoff valve to close automatically., Why must the flight crew oxygen cylinder shutoff valve be opened slowly during servicing or return to service?, Opening the valve rapidly can cause the regulator to lock permanently at its maximum outlet pressure., Rapid pressurization can cause adiabatic gas compression and a significant temperature rise, creating a fire or explosion hazard., Rapid valve movement can cause the pressure transducer to generate an incorrect full-scale pressure indication., The flight crew oxygen mask is removed from its stowage box, the left door is closed, and oxygen is flowing normally. Which combination of indications confirms both valve position and actual oxygen flow?, The white OXY ON flag shows that the stowage-box shutoff valve is open, while the yellow-cross flow indicator confirms oxygen flow., The yellow-cross flow indicator confirms only that the shutoff valve is open, while the OXY ON flag confirms actual oxygen mass flow., The OXY ON flag and yellow-cross indicator both respond only to oxygen pressure and cannot distinguish valve position from flow., A flight crew oxygen mask is operating in normal diluter-demand mode as cabin altitude increases. How is the oxygen concentration supplied to the user progressively changed?, The pressure-reducing regulator increases cylinder outlet pressure in proportion to cabin altitude., An aneroid metering valve varies the proportion of cabin air mixed with oxygen according to cabin pressure altitude., The oxygen-system pressure transducer commands the mask regulator to progressively reduce ambient-air flow., Cabin altitude rises above 14,000 feet and the passenger oxygen system deploys automatically. What causes power to the oxygen-box door latch actuators to stop approximately five seconds later while the system indication remains latched?, A time delay within the automatic oxygen deployment relay de-energizes the actuator circuit, while the oxygen indication relay remains latched., The altitude pressure switch reopens automatically after five seconds, but a separate timer keeps the indications active., The door latch actuators contain internal thermal switches that remove their own power after deployment., A Passenger Service Unit oxygen door has opened following deployment, but no passenger has pulled down a mask. What is the status of the chemical oxygen generator?, The generator starts automatically as soon as the door latch actuator releases the oxygen-box door., The generator has not yet started because pulling a mask is required to tension the lanyard and release cable that removes the firing-mechanism release pin., The generator begins producing oxygen as soon as the altitude pressure switch closes, regardless of mask movement., A chemical oxygen generator has been activated accidentally during maintenance. Why can oxygen production not simply be shut off once the firing sequence has started?, The firing pin remains mechanically locked against the percussion cap until the generator pressure falls to zero., The outlet valve assembly cannot close until the membrane foil cools below its activation temperature., The sodium chlorate and iron chemical reaction continues until the sodium chlorate is consumed., A lavatory oxygen cylinder has operated normally following mask deployment. Which observation confirms that the cylinder has been activated rather than emptied by an overpressure condition?, The activation pin has been removed; an overpressure discharge is instead indicated by broken tape over the pressure-relief port., The pressure-relief tape remains intact and the safety pin is found installed., The oxygen-box door remains open while the activation pin remains installed., A deployed passenger oxygen mask reservoir bag becomes empty during inhalation even though the oxygen source is still supplying constant flow. How can the user continue to inhale?, The exhalation valve reverses direction and permits ambient air to enter through the mask exhaust path., The ambient-air valve opens after the stored oxygen in the reservoir bag is depleted, allowing cabin air into the mask., The lanyard automatically increases generator output until the reservoir bag refills., A portable oxygen cylinder shutoff valve is ON, but no oxygen flows from an unused constant-flow outlet. Why is this normal?, The pressure regulator does not supply outlet pressure until both constant-flow outlets are connected., Each outlet contains a check valve that remains closed until the mask bayonet connector mechanically unseats it., The cylinder head detects hose pressure and electrically opens the applicable outlet valve.

ATA 35

by
Print
Embed

Leaderboard

Visual style

Options

Switch template

Continue editing: ?