CPL Human Factors cheat sheet

Hypoxia types: hypoxic (reduced alveolar PO2, e.g., altitude), hypemic (reduced oxygen-carrying capacity, e.g., anaemia, CO), stagnant (circulatory failure), histotoxic (cell cannot use oxygen, e.g., cyanide).

Time of useful consciousness at 25,000 ft is about 3-5 minutes; at 35,000 ft about 30-60 seconds; at 40,000 ft about 15-20 seconds.

Cabin altitude above 10,000 ft requires supplemental oxygen for crew; above 14,000 ft oxygen is required for all occupants in most operational rules.

Hyperventilation causes hypocapnia and cerebral vasoconstriction; symptoms mimic hypoxia. Treatment is controlled breathing at reduced rate, not oxygen alone.

Spatial disorientation: somatogravic illusion misinterprets linear acceleration as pitch; somatogyral illusion misinterprets sustained rotation as continued turning.

Vestibular system: semicircular canals sense angular acceleration; otolith organs sense linear acceleration and gravity. Both can mislead in IMC.

Visual illusions: black-hole approach makes a runway appear high and near; runway width illusion alters perceived glidepath; whiteout removes horizon cues.

Decompression sickness: nitrogen bubbles form on rapid decompression; symptoms include joint pain, chest pain, and neurological signs. Treatment is descent plus 100% oxygen.

G-LOC occurs when cerebral perfusion falls during sustained high +Gz; A-LOC is a lesser state with degraded cognition before full loss of consciousness.

Hypoxia types: hypoxic (reduced alveolar PO2, e.g., altitude), hypemic (reduced oxygen-carrying capacity, e.g., anaemia, CO), stagnant (circulatory failure), histotoxic (cell cannot use oxygen, e.g., cyanide).

Time of useful consciousness at 25,000 ft is about 3-5 minutes; at 35,000 ft about 30-60 seconds; at 40,000 ft about 15-20 seconds.

Cabin altitude above 10,000 ft requires supplemental oxygen for crew; above 14,000 ft oxygen is required for all occupants in most operational rules.

Hyperventilation causes hypocapnia and cerebral vasoconstriction; symptoms mimic hypoxia. Treatment is controlled breathing at reduced rate, not oxygen alone.

Spatial disorientation: somatogravic illusion misinterprets linear acceleration as pitch; somatogyral illusion misinterprets sustained rotation as continued turning.

Vestibular system: semicircular canals sense angular acceleration; otolith organs sense linear acceleration and gravity. Both can mislead in IMC.

Visual illusions: black-hole approach makes a runway appear high and near; runway width illusion alters perceived glidepath; whiteout removes horizon cues.

Decompression sickness: nitrogen bubbles form on rapid decompression; symptoms include joint pain, chest pain, and neurological signs. Treatment is descent plus 100% oxygen.

G-LOC occurs when cerebral perfusion falls during sustained high +Gz; A-LOC is a lesser state with degraded cognition before full loss of consciousness.