Human Factors

Objective

By the end of this lesson, the student will be able to identify at least three aeromedical conditions from FAA-S-ACS-15 PH.I.H.K1, associate their symptoms with causes and corrective actions, demonstrate knowledge of alcohol and drug regulations per 14 CFR 91.17 and 14 CFR 67.307, explain the effects of alcohol and medications on pilot performance, apply aeronautical decision-making principles including hazardous attitude recognition, and perform a comprehensive self-assessment for fitness for flight per FAA-S-ACS-15 PH.I.H.S1 and PH.I.H.S2.

Content

Aeromedical and Physiological Issues (PH.I.H.K1)

Hypoxia occurs when body tissues don’t receive adequate oxygen. At helicopter operating altitudes, this primarily affects pilots during high altitude operations or when using supplemental oxygen systems improperly. Four types exist: hypoxic (altitude), hypemic (carbon monoxide), histotoxic (alcohol/drugs), and stagnant (circulation problems). Symptoms include euphoria, headache, decreased reaction time, impaired judgment, and cyanosis. Recognition is difficult because euphoria masks the condition—like being intoxicated, you feel great while performance degrades. Corrective actions include descending to lower altitude, using supplemental oxygen, or landing immediately.

Hyperventilation results from excessive breathing rate, often triggered by stress or anxiety during challenging flight conditions like autorotations or confined area operations. It reduces carbon dioxide levels, causing lightheadedness, tingling extremities, muscle spasms, and unconsciousness. Unlike hypoxia, hyperventilation symptoms appear rapidly. Corrective actions include slowing breathing rate, breathing into a paper bag, or talking aloud to regulate breathing rhythm.

Middle ear and sinus problems plague helicopter pilots during altitude changes. During climbs, expanding air in middle ear must escape through Eustachian tubes. During descents, outside air must enter to equalize pressure. Blocked passages from colds or allergies prevent equalization, causing severe pain and potential ear drum rupture. Sinuses face similar issues. Prevention includes avoiding flight with upper respiratory infections. During flight, gentle Valsalva maneuvers help equalize pressure.

Spatial disorientation occurs when sensory systems provide conflicting information about aircraft attitude and position. Visual system (most reliable), vestibular system (inner ear), and proprioceptive system (body position) sometimes disagree. Helicopter pilots face unique challenges during hovering flight when visual references are limited, such as over water or in dust clouds. The leans, graveyard spin, and false horizon illusions are common. Trust flight instruments over physical sensations. If experiencing spatial disorientation, establish straight and level flight using instruments.

Motion sickness affects passengers and occasionally pilots, especially during training flights with excessive maneuvering. Conflicting signals between visual and vestibular systems trigger nausea, vomiting, and cold sweats. Prevention includes good ventilation, avoiding sudden movements, focusing on outside references, and gradual exposure to flight. Once symptoms begin, open fresh air vents, focus on horizon, and avoid head movements.

Carbon monoxide poisoning represents a deadly threat in helicopters with cabin heaters. This colorless, odorless gas binds to hemoglobin 200 times more readily than oxygen. Symptoms include headache, drowsiness, dizziness—similar to hypoxia but often accompanied by cherry-red skin color. Unlike hypoxia, carbon monoxide effects persist even after landing. Immediate actions include turning off cabin heat, opening windows, landing as soon as possible, and seeking medical attention.

Stress impacts decision-making and performance. Acute stress from emergency situations can enhance performance initially but quickly degrades fine motor skills. Chronic stress from training pressure or personal issues accumulates over time. Stress causes tunnel vision, reduced reaction time, and poor judgment. Manage through physical fitness, adequate rest, proper nutrition, and stress reduction techniques.

Fatigue impairs performance similarly to alcohol intoxication. Acute fatigue from one poor night’s sleep affects reaction time and judgment. Chronic fatigue from sustained inadequate rest is cumulative and dangerous. Microsleeps during flight are deadly. The only cure is adequate rest—caffeine provides temporary alertness but doesn’t replace sleep. Recognize fatigue symptoms and don’t fly when tired.

Dehydration and nutrition significantly impact pilot performance. Dehydration reduces blood volume, causing fatigue and reduced cognitive function. Hot weather operations and high altitude flying accelerate fluid loss. Proper hydration requires drinking water before feeling thirsty. Avoid alcohol and caffeine which promote dehydration. Nutrition affects blood sugar levels—avoid heavy meals before flying which cause drowsiness, and avoid flying on empty stomach which causes hypoglycemia.

Hypothermia occurs when body core temperature drops below normal. Early stages include shivering, reduced dexterity, and impaired judgment. Advanced stages involve violent shivering, muscle rigidity, and unconsciousness. Helicopter pilots face exposure during winter operations, water operations, and emergency landings. Prevention includes proper clothing, limiting exposure time, and maintaining cabin heat. Treatment requires gradual rewarming and immediate medical attention for severe cases.

Optical illusions deceive pilots during visual flight. Runway width illusions make narrow runways appear farther away and wide runways closer. Slope illusions on sloping terrain affect height perception. False horizon illusions occur when confusing ground lights with stars. Autokinesis makes stationary lights appear to move after staring. Combat illusions by using multiple visual references, maintaining good scanning technique, and trusting instruments when visual references are poor.

Dissolved nitrogen affects pilots who scuba dive before flying. Nitrogen absorbed under pressure forms bubbles when pressure reduces rapidly during ascent—either underwater or in aircraft. These bubbles cause decompression sickness (bends) with joint pain, paralysis, or death. Wait 12 hours after non-decompression dives and 24 hours after decompression dives before flying above sea level.

Alcohol and Drug Regulations (PH.I.H.K2)

14 CFR 91.17 prohibits acting as crewmember within 8 hours of alcohol consumption, while under the influence of alcohol, with blood alcohol content of 0.04% or higher, or while using drugs that affect safety. This “8 hours bottle to throttle” rule represents minimum time—alcohol metabolism varies by individual.

14 CFR 67.307 requires reporting drug or alcohol-related motor vehicle convictions to FAA within 60 days. Conviction may result in certificate suspension or revocation.

Effects of Alcohol, Drugs, and Medications (PH.I.H.K3)

Alcohol impairs judgment, coordination, and reaction time at levels well below legal intoxication limits. Small amounts affect night vision and increase susceptibility to spatial disorientation. Alcohol remains in system longer than subjective feelings suggest—hangovers indicate continued impairment.

Drugs, both illegal and prescription, affect pilot performance unpredictably. Marijuana impairs short-term memory and time perception for hours after use. Stimulants mask fatigue initially but cause severe performance degradation when they wear off. Depressants slow reaction time and cause drowsiness.

Over-the-counter medications often contain ingredients affecting alertness. Antihistamines cause drowsiness and slow reaction time. Decongestants may cause anxiety or rapid heartbeat. Always consult aviation medical examiner before flying while taking any medication.

Aeronautical Decision-Making (PH.I.H.K4)

Single-Pilot Resource Management (SRM) helps helicopter pilots manage risks effectively. The five pillars include: task management (prioritizing and organizing), automation management (understanding systems), risk management (identifying and mitigating hazards), situational awareness (maintaining accurate mental model), and controlled flight into terrain awareness.

DECIDE model provides systematic decision-making framework: Detect change requiring attention, Estimate significance of change, Choose desirable outcome, Identify actions to achieve outcome, Do the necessary action, Evaluate effect of action.

Risk management involves identifying hazards, assessing risks, and implementing controls. Use PAVE checklist: Pilot (experience, currency, health), Aircraft (airworthiness, equipment, performance), enVironment (weather, terrain, airports), External pressures (schedule, passengers, personal minimums).

Risk Management Items

Aeromedical and physiological issues (PH.I.H.R1) require constant monitoring. Pilots must recognize when physical or mental condition degrades flight safety. Self-grounding when sick, tired, or stressed demonstrates good judgment. Understanding how various conditions affect performance helps pilots make informed decisions.

Hazardous attitudes (PH.I.H.R2) include anti-authority (“Don’t tell me what to do”), impulsivity (“Do something quickly”), invulnerability (“It won’t happen to me”), macho (“I can do it”), and resignation (“What’s the use?”). Each attitude has an antidote: anti-authority—follow the rules, they’re usually right; impulsivity—not so fast, think first; invulnerability—it could happen to me; macho—taking chances is foolish; resignation—I’m not helpless, I can make a difference.

Distractions, task prioritization, and loss of situational awareness (PH.I.H.R3) threaten flight safety. Aviate, navigate, communicate priority system helps maintain focus. When overwhelmed, fly the helicopter first, then address other issues. Regular situational awareness checks using “where am I, where am I going, what’s the helicopter doing” prevent spatial disorientation.

Confirmation and expectation bias (PH.I.H.R4) cause pilots to see what they expect rather than reality. Confirmation bias seeks information supporting preconceived notions while ignoring contradictory evidence. Expectation bias interprets ambiguous information consistent with expectations. Combat bias through systematic information gathering, considering alternative explanations, and seeking input from others.

Schedule

Equipment

• FAA-H-8083-21B Helicopter Flying Handbook
• FAA-H-8083-25B Pilot’s Handbook of Aeronautical Knowledge
• FAA-S-ACS-15 Private Pilot Helicopter Airman Certification Standards
• 14 CFR Parts 61, 67, 91
• Whiteboard or visual aids showing physiological condition symptoms
• Scenario cards for self-assessment practice
• Aviation medical examiner contact information

Instructor Actions

1. Begin lesson by asking student about recent experiences with fatigue, stress, or physical discomfort during flight training
2. Explain lesson objectives and emphasize that human factors cause majority of aviation accidents
3. Demonstrate hypoxia symptoms by having student breathe rapidly then hold breath, noting performance changes
4. Use analogy: “Hypoxia is like being drunk—you feel great while your performance goes to hell”
5. Show pictures of spatial disorientation demonstrations, explaining conflicting sensory inputs
6. Demonstrate Valsalva maneuver for ear pressure equalization
7. Explain carbon monoxide danger: “Invisible killer—you won’t smell it, taste it, or see it coming”
8. Review 14 CFR 91.17 requirements, emphasizing “8 hours bottle to throttle” is minimum, not recommendation
9. Discuss medication effects: “If it makes you drowsy on the ground, it’ll make you drowsy in the air”
10. Introduce DECIDE model with helicopter-specific examples
11. Present hazardous attitudes with helicopter scenarios: macho pilot attempting weather minimums
12. Demonstrate confirmation bias using weather interpretation scenarios
13. Practice PAVE checklist with current flight conditions
14. Present self-assessment scenarios requiring go/no-go decisions
15. Have student identify three physiological conditions, symptoms, and corrective actions
16. Guide student through personal minimums development exercise
17. Review lesson objectives and assess student understanding

Student Actions

1. Actively participate in lesson discussion, sharing relevant personal experiences
2. Identify symptoms, causes, and corrective actions for assigned physiological conditions
3. Practice Valsalva maneuver for ear pressure relief
4. Recite alcohol and drug regulations from memory
5. Apply DECIDE model to presented flight scenarios
6. Identify hazardous attitudes in given situations and state appropriate antidotes
7. Complete PAVE assessment for sample flight scenario
8. Perform self-assessment for fitness for flight given various physical and mental conditions
9. Develop personal minimums for weather, fatigue, and stress levels
10. Demonstrate knowledge by associating at least three physiological conditions with symptoms and corrective actions
11. Ask questions to clarify understanding of complex topics
12. Take notes on key regulations and decision-making tools

Completion Standards

Student demonstrates satisfactory knowledge of human factors per FAA-S-ACS-15 PH.I.H by:

• PH.I.H.S1: Accurately associating symptoms and effects for at least three conditions from K1a-K1l with appropriate causes and corrective actions, including specific details such as hypoxia symptoms (euphoria, headache, impaired judgment) with cause (inadequate oxygen) and corrective action (descend or use supplemental oxygen)

• PH.I.H.S2: Successfully performing self-assessment for fitness for flight by correctly identifying personal limitations, applying personal minimums to given scenarios, and making appropriate go/no-go decisions based on pilot condition, aircraft status, environment, and external pressures

• Knowledge demonstration: Correctly stating 14 CFR 91.17 requirements including 8-hour rule and 0.04% blood alcohol limit, explaining effects of alcohol and common medications on pilot performance, and identifying all five hazardous attitudes with appropriate antidotes

• Risk management: Recognizing aeromedical factors affecting flight safety, identifying situations requiring self-grounding, demonstrating understanding of confirmation and expectation bias through scenario analysis, and explaining task prioritization using aviate-navigate-communicate hierarchy

• Decision-making: Successfully applying DECIDE model to flight scenarios, completing PAVE checklist assessment, and demonstrating understanding of SRM principles appropriate for single-pilot helicopter operations