5.4 Physiological Factors Affecting Pilots

5.4 Physiological Factors Affecting Pilots

Even though remote pilots are on the ground, physiological factors can significantly impair their ability to operate safely. The Part 107 exam tests your understanding of how physical and mental states affect pilot performance.

Vision and Visual Scanning

Visual Acuity:

• Maintaining visual line of sight requires good visual acuity
• Bright sunlight can cause glare that makes it difficult to see the drone
• Polarized sunglasses can help with glare but may affect perception of LCD screens on controllers
• At night, it takes 20-30 minutes for eyes to fully adapt to darkness (dark adaptation)

Visual Scanning Technique:

• Do NOT stare at the drone continuously — use a scanning pattern
• Scan the sky in sectors, pausing briefly in each sector
• Focus on areas where manned aircraft are most likely to appear
• The VO should scan different sectors than the PIC to maximize coverage

Empty-Field Myopia:

• When looking at a clear, featureless sky, the eyes tend to focus at a resting distance of about 10-30 feet
• This makes it difficult to spot distant aircraft
• Counteract by periodically focusing on distant objects or the horizon

Fatigue

Types of Fatigue:

• Acute fatigue — short-term exhaustion from a long day or insufficient sleep
• Chronic fatigue — long-term exhaustion from ongoing sleep deprivation or overwork
• Skill fatigue — degraded performance on specific tasks from prolonged repetition

Fatigue Effects:

• Slowed reaction time
• Impaired judgment and decision making
• Reduced situational awareness
• Increased risk-taking behavior
• Difficulty concentrating
• Tunneling of attention (focusing on one thing, missing others)

Mitigation:

• Get adequate sleep (7-8 hours) before flying
• Take breaks during extended operations
• Do not fly if you have been awake for more than 12-15 hours
• Stay hydrated and fed — hunger and dehydration worsen fatigue

Hypoxia (for Context)

While hypoxia primarily affects pilots at higher altitudes:

• Hypoxia = insufficient oxygen to the brain and body
• Symptoms: headache, dizziness, euphoria, impaired judgment, visual impairment
• Generally not a concern for remote pilots at ground level
• Could be relevant at very high-altitude operating locations (e.g., mountain operations above 10,000 ft)

Stress

Effects of Stress on Pilot Performance:

• Narrowing of attention (tunnel vision)
• Increased error rate
• Poor decision making
• Irritability and communication breakdowns
• Physical symptoms: elevated heart rate, sweating, muscle tension

Stress Management:

• Use the IMSAFE checklist before every flight
• Set personal minimums that are more conservative when stressed
• Practice emergency procedures so they become automatic under stress
• Communicate with crew about stress levels

Heat-Related Illness

Remote pilots operating outdoors in hot conditions are susceptible to:

Alcohol and Drugs

Part 107 / Part 91 requirements:

For the Exam: The 8-hour bottle-to-throttle rule and 0.04% BAC limit are frequently tested. Also know that fatigue and stress are significant impairments that the PIC must self-assess before every flight.