COMSAE PHASE 2 – FORM 109 PRACTICE
EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2025/2026 Q&A | INSTANT
DOWNLOAD PDF
1. A loud explosive noise often heard during rapid decompression is known as:
A. Metal fatigue noise
B. Air-lock noise
C. Boom noise
D. Pressure release rumble
Correct Answer: C. Boom noise
Rationale: Boom noise occurs when the rapid pressure change creates a sonic
shock causing a "boom."
2. During cockpit decompression, the first physiological effect is usually:
A. Hypoxia
B. Ear block
C. Sinus squeeze
D. Decompression sickness
Correct Answer: B. Ear block
,Rationale: Ear block (eustachian tube imbalance) often manifests before hypoxia
in rapid decompression.
3. The useful time of consciousness at 40,000 ft is approximately:
A. 30 seconds
B. 15 seconds
C. 45 seconds
D. 5 seconds
Correct Answer: B. 15 seconds
Rationale: Time-of-useful consciousness decreases with altitude; at 40,000 ft it is
about 15 seconds.
4. Boyle's Law relates pressure and volume:
A. Directly proportional
B. Inversely proportional
C. Unrelated
D. Same volume, same pressure
Correct Answer: B. Inversely proportional
Rationale: Boyle's Law: at constant temperature, pressure × volume = constant
(inverse relationship).
,5. Gas emboli are most likely prevented by:
A. Slow, controlled decompression
B. Quick ascent
C. Breath-holding
D. Rapid compression
Correct Answer: A. Slow, controlled decompression
Rationale: Slow decompression allows gas to diffuse safely rather than forming
bubbles (embolism).
6. In case of rapid decompression, you should:
A. Stand up quickly
B. Don oxygen immediately
C. Ignore until needed
D. Begin pressurizing cabin
Correct Answer: B. Don oxygen immediately
Rationale: Oxygen immediately restores oxygen partial pressure and counters
hypoxia.
7. The term "hypoxia" means:
A. Excessive oxygen
B. Low oxygen
C. No pressure
D. High carbon dioxide
, Correct Answer: B. Low oxygen
Rationale: Hypoxia refers to a deficiency in the amount of oxygen reaching
tissues.
8. Decompression sickness most commonly occurs when:
A. Pressure increases
B. Pressure decreases quickly
C. Temperature rises
D. Carbon dioxide rises
Correct Answer: B. Pressure decreases quickly
Rationale: Rapid reduction in ambient pressure allows nitrogen to come out of
solution, forming bubbles.
9. Explosive decompression is defined as decompression occurring in less
than:
A. 1 second
B. 0.5 seconds
C. 10 seconds
D. 5 seconds
Correct Answer: B. 0.5 seconds
Rationale: Explosive decompression is defined as a pressure change that occurs
faster than the lungs can decompress, typically under 0.5 seconds.
EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2025/2026 Q&A | INSTANT
DOWNLOAD PDF
1. A loud explosive noise often heard during rapid decompression is known as:
A. Metal fatigue noise
B. Air-lock noise
C. Boom noise
D. Pressure release rumble
Correct Answer: C. Boom noise
Rationale: Boom noise occurs when the rapid pressure change creates a sonic
shock causing a "boom."
2. During cockpit decompression, the first physiological effect is usually:
A. Hypoxia
B. Ear block
C. Sinus squeeze
D. Decompression sickness
Correct Answer: B. Ear block
,Rationale: Ear block (eustachian tube imbalance) often manifests before hypoxia
in rapid decompression.
3. The useful time of consciousness at 40,000 ft is approximately:
A. 30 seconds
B. 15 seconds
C. 45 seconds
D. 5 seconds
Correct Answer: B. 15 seconds
Rationale: Time-of-useful consciousness decreases with altitude; at 40,000 ft it is
about 15 seconds.
4. Boyle's Law relates pressure and volume:
A. Directly proportional
B. Inversely proportional
C. Unrelated
D. Same volume, same pressure
Correct Answer: B. Inversely proportional
Rationale: Boyle's Law: at constant temperature, pressure × volume = constant
(inverse relationship).
,5. Gas emboli are most likely prevented by:
A. Slow, controlled decompression
B. Quick ascent
C. Breath-holding
D. Rapid compression
Correct Answer: A. Slow, controlled decompression
Rationale: Slow decompression allows gas to diffuse safely rather than forming
bubbles (embolism).
6. In case of rapid decompression, you should:
A. Stand up quickly
B. Don oxygen immediately
C. Ignore until needed
D. Begin pressurizing cabin
Correct Answer: B. Don oxygen immediately
Rationale: Oxygen immediately restores oxygen partial pressure and counters
hypoxia.
7. The term "hypoxia" means:
A. Excessive oxygen
B. Low oxygen
C. No pressure
D. High carbon dioxide
, Correct Answer: B. Low oxygen
Rationale: Hypoxia refers to a deficiency in the amount of oxygen reaching
tissues.
8. Decompression sickness most commonly occurs when:
A. Pressure increases
B. Pressure decreases quickly
C. Temperature rises
D. Carbon dioxide rises
Correct Answer: B. Pressure decreases quickly
Rationale: Rapid reduction in ambient pressure allows nitrogen to come out of
solution, forming bubbles.
9. Explosive decompression is defined as decompression occurring in less
than:
A. 1 second
B. 0.5 seconds
C. 10 seconds
D. 5 seconds
Correct Answer: B. 0.5 seconds
Rationale: Explosive decompression is defined as a pressure change that occurs
faster than the lungs can decompress, typically under 0.5 seconds.
