Safety and Emergency EquipmentAircraft & Engines — DGCA CPL practice questions
Question 1 of 5
The Time of Useful Consciousness at 35,000 ft is approximately:
All 5 questions — Safety and Emergency Equipment
Aircraft & Engines · DGCA CPL. The correct option is marked on each.
Q1. The Time of Useful Consciousness at 35,000 ft is approximately:
- A.5 minutes
- B.2 minutes
- C.30-45 seconds✓
- D.10 seconds
Why: At 35,000 ft a person has only 30-45 seconds of useful consciousness after losing oxygen — why crew masks must don in seconds.
Q2. Passenger chemical oxygen generators:
- A.Can be switched off when not needed
- B.Once started cannot be stopped and supply about 15 minutes of oxygen✓
- C.Provide oxygen for the whole flight
- D.Use compressed oxygen bottles
Why: Pulling the mask starts a sodium-chlorate/iron reaction that runs to completion — roughly 15 minutes of flow.
Q3. Crew diluter-demand oxygen masks supply 100% oxygen above approximately:
- A.10,000 ft
- B.18,000 ft
- C.32,000 ft✓
- D.40,000 ft
Why: Below ~32,000 ft the regulator mixes cabin air with oxygen on inhalation; above it, 100% oxygen is delivered.
Q4. Gaseous oxygen is stored in cylinders coloured:
- A.Red
- B.Green✓
- C.Yellow
- D.Black
Why: High-pressure oxygen cylinders are green.
Q5. Engine and APU fire zones are typically monitored by:
- A.Smoke detectors
- B.A continuous fire-wire or gas-filled sensing loop triggered by heat✓
- C.CCTV cameras
- D.The EGT gauge alone
Why: Continuous-loop detectors around the fire zones alarm at a set temperature; smoke detectors guard cargo holds and lavatories.