Oxygen Systems Repair Practice Exam

FAA Repairman Certificate – Aircraft Oxygen Systems Repair Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What type of oxygen system is most commonly used in general aviation

aircraft?

• Chemical oxygen generator system
• Continuous flow system
• Demand flow system
• Pressure-demand system

Rationale: Continuous flow systems are simple and inexpensive, making

them the standard for general aviation where high altitudes and large oxygen demand are uncommon.

• In a continuous flow oxygen system, what controls the rate of oxygen

flow to the user? 1 / 4

• Pressure regulator only
• Flowmeter or calibrated orifice
• Check valve
• Shutoff valve

Rationale: Flowmeters or calibrated orifices ensure a steady oxygen flow

rate regardless of pressure variations.

• What type of oxygen system is typically used in high-altitude jet

aircraft?

• Continuous flow
• Diluter-demand
• Pressure-demand
• Chemical oxygen generator

Rationale: Pressure-demand systems supply oxygen at a pressure higher

than ambient, necessary for breathing at extreme altitudes above 40,000 feet.

• What color coding is used for aircraft oxygen cylinders?
• Yellow
• Red
• Green
• Blue 2 / 4

Rationale: Aviation oxygen cylinders are color-coded green to distinguish

them from other gas systems.

• What type of gas must be used in aircraft oxygen systems?
• Industrial oxygen
• Medical oxygen
• Aviator’s breathing oxygen (99.5% pure)
• Nitrous oxide mixture

Rationale: Aviator’s breathing oxygen is moisture-free to prevent freezing

at high altitude and meets FAA purity standards.

• What is the main purpose of a pressure reducer in an oxygen system?
• To increase pressure to the mask
• To lower cylinder pressure to a usable level
• To filter impurities
• To prevent backflow

Rationale: High cylinder pressure is reduced to system operating pressure

for safe delivery to users.

• Which component prevents reverse flow of oxygen in the system?
• Pressure reducer
• Flowmeter 3 / 4

• Check valve
• Relief valve

Rationale: Check valves maintain one-way flow and prevent contamination

or pressure loss.

• What is the approximate full pressure of an aircraft oxygen cylinder?
• 500 psi
• 1200 psi
• 1800–2000 psi
• 3000 psi

Rationale: Most aviation oxygen cylinders are charged to around 1800–

2000 psi.

• Before servicing an oxygen system, what must the technician ensure?
• The system is pressurized
• The area is wet
• The area is clean and free of oil or grease
• The cylinder is warm

Rationale: Oil or grease can react violently with oxygen, causing fire or

explosion.

• / 4