ATPL Human Performance and Limitations 1 — Questions and Answers
Question 1: Time of Useful Consciousness (TUC) at FL350 without supplemental oxygen is approximately:
- 30–60 seconds (Correct answer)
- 1–2 minutes
- 3–5 minutes
- 5–10 minutes
Correct answer: 30–60 seconds
At FL350 (approximately 35,000 ft), TUC is only 30–60 seconds due to the very low partial pressure of oxygen, leaving pilots very little time to don oxygen masks.
Question 2: Which of the following best describes spatial disorientation in flight?
- Misreading the altimeter during climb
- A false perception of the aircraft's attitude, motion, or position (Correct answer)
- Visual illusions caused by runway slope
- Confusion about ATC instructions
Correct answer: A false perception of the aircraft's attitude, motion, or position
Spatial disorientation is a false or incorrect perception of the aircraft's position, attitude, or movement relative to the earth, caused by misleading sensory information.
Question 3: The 'leans' is a form of spatial disorientation caused by:
- Incorrect altimeter setting
- A gradual undetected roll with a rapid correction sensed as a new roll (Correct answer)
- Vertigo from looking outside during cloud flight
- G-force buildup during maneuvering
Correct answer: A gradual undetected roll with a rapid correction sensed as a new roll
The leans occur when a gradual undetected bank is corrected quickly — the rapid correction is sensed as a bank in the opposite direction, causing the pilot to feel leaned toward the original bank.
Question 4: Hypoxia at altitude primarily affects which cognitive functions first?
- Motor coordination and walking balance
- Higher cognitive functions including judgment and decision-making (Correct answer)
- Hearing acuity
- Long-term memory recall
Correct answer: Higher cognitive functions including judgment and decision-making
Hypoxia impairs higher-order cognitive functions first — including judgment, reasoning, and decision-making — while the pilot may feel euphoric and unaware of impairment.
Question 5: Crew Resource Management (CRM) training primarily aims to reduce accidents caused by:
- Mechanical failures and fuel exhaustion
- Communication breakdowns and poor decision-making in the cockpit (Correct answer)
- Pilot medical incapacitation
- Navigation system errors
Correct answer: Communication breakdowns and poor decision-making in the cockpit
CRM training addresses the human factors root cause of most aviation accidents: poor communication, ineffective crew coordination, and flawed decision-making under stress.
Question 6: The SHELL model in human factors stands for:
- Software, Hardware, Environment, Liveware, Liveware (Correct answer)
- Systems, Humans, Engineering, Logic, Limitations
- Safety, Hazard, Error, Loss, Likelihood
- Structure, Hardware, Environment, Learning, Laws
Correct answer: Software, Hardware, Environment, Liveware, Liveware
The SHELL model represents the components of aviation systems: Software (procedures/regulations), Hardware (equipment), Environment (physical/organizational), and Liveware (humans), with the central Liveware being the pilot.
ATPL Human Performance and Limitations 1
Time of Useful Consciousness (TUC) at FL350 without supplemental oxygen is approximately: