Task I.H
Human Factors
To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with personal health, flight physiology, and aeromedical and human factors related to safety of flight.
References: AIM; FAA-H-8083-2, FAA-H-8083-3, FAA-H-8083-25
Quick Review
Most accidents have a human-factors link — recognizing impairment and managing risk is as important as stick-and-rudder skill.
Flight physiology
- Vestibular — inner-ear motion sensing
- Somatosensory — "seat of the pants" pressure and muscle cues
- Visual — the most reliable of the three
The visual system dominates; the other two mislead in IMC.
Trapped air in the ear or sinus expands and contracts with altitude. Clear a block by swallowing, yawning, or the Valsalva maneuver (gently exhale against a pinched nose and closed mouth). Don't fly with congestion — descents are the painful part.
The four types, by cause:
- Hypoxic — insufficient O₂ at altitude
- Hypemic — blood can't carry O₂ (CO poisoning, anemia)
- Histotoxic — cells can't use O₂ (alcohol/drugs)
- Stagnant — poor circulation (G-forces)
Common symptoms: euphoria, impaired judgment, cyanosis, tunnel vision, headache.
Over-breathing blows off too much CO₂, and the symptoms mimic hypoxia. Slow the breathing rate, talk aloud, or breathe into a bag.
An odorless exhaust gas, often from a cracked heater muff. Symptoms: headache, dizziness, drowsiness. Turn off the heater, open the fresh-air vents, use 100% O₂ if available, and land.
- Narrow runway → feel too high (fly low)
- Wide runway → feel too low (fly high)
- Upsloping runway/terrain → feel too high
- Plus featureless-terrain / black-hole approaches and autokinesis (a static light appears to move)
- 12 hours after a no-decompression dive, before flying to cabin altitudes up to 8,000 ft
- 24 hours after a dive requiring a controlled ascent
- 24 hours after any dive, before flying above 8,000 ft
No flying under any of these:
- Within 8 hours of "bottle to throttle"
- While under the influence
- With a BAC of 0.04 or greater
Alcohol or drug convictions must be reported (91.17, 61.15).
- Above 12,500 ft cabin altitude for more than 30 minutes — required minimum flight crew must use O₂
- Above 14,000 ft — crew uses O₂ continuously
- Above 15,000 ft — each occupant must be provided O₂
Decision making and resource management
A systematic, structured approach to consistently determining the best course of action for a given set of circumstances. Its two defining elements are hazard and risk.
- Anti-authority ("Don't tell me") → Follow the rules; they're usually right.
- Impulsivity ("Do something quickly") → Not so fast — think first.
- Invulnerability ("It won't happen to me") → It could happen to me.
- Macho ("I can do it") → Taking chances is foolish.
- Resignation ("What's the use?") → I'm not helpless; I can make a difference.
Managing all available resources — onboard (instruments, avionics, autopilot, checklists, passengers) and outside (ATC, flight service, flight following) — to reduce workload and maintain safety. SRM is the umbrella over the tools below.
Prioritize and sequence tasks so you're never saturated: aviate, navigate, communicate, in that order. Offload low-priority items, use checklists, and plan high-workload phases in advance.
An accurate, continuous picture of the aircraft, environment, and your own state. Lost SA shows up as fixation, confusion, or falling behind the airplane; rebuild it by stepping back to aviate-navigate-communicate.
Controlled flight into terrain — a flyable airplane flown into the ground, usually from lost SA, low visibility, or night/terrain. Mitigate with terrain awareness, proper altitudes, and not descending below safe minimums without positive position knowledge.
Know what the avionics/autopilot are doing and stay ahead of them; don't let heads-down programming erode your scan or SA. Be ready to drop to a lower level of automation and hand-fly.
Notify the nearest NTSB office immediately for an aircraft accident (death, serious injury, or substantial damage) or any of these serious incidents:
- Flight control system malfunction or failure
- A required crewmember unable to perform duties from injury/illness
- In-flight fire
- Mid-air collision
- Certain turbine-engine failures
- Property damage (other than the aircraft) over $25,000
Written report (Form 6120): within 10 days for an accident; within 7 days if an overdue aircraft is still missing (49 CFR 830).
Deep Dive
Runway illusions at a glance
The pattern to lock in: the runway makes you feel like you're at the wrong height, and the "correction" you fly puts you on the wrong approach path (PHAK ch 16, AIM 8-1-5).
| Runway | Illusion | Resulting tendency |
|---|---|---|
| Narrower than usual | You seem higher than you are | Fly a lower-than-normal approach |
| Wider than usual | You seem lower than you are | Fly a higher-than-normal approach |
| Upsloping | You seem higher than you are | Fly a lower-than-normal approach |
| Downsloping | You seem lower than you are | Fly a higher-than-normal approach |
Narrow pairs with upsloping (both drive you low); wide pairs with downsloping (both drive you high). Antidote for all of them: know the runway's dimensions and slope beforehand (Chart Supplement) and back up the sight picture with glide-path aids like a VASI/PAPI.
Hazardous attitudes — RAIIM
Physiology, one level deeper
Carbon monoxide (CO — not CO₂) bonds to the hemoglobin in red blood cells roughly 200 times more readily than oxygen does, so even a trace of exhaust in the cabin progressively crowds oxygen off the blood cells and causes hypemic hypoxia. That's why a small crack in the heater muff matters, and why smoking (which loads CO into the blood) raises susceptibility before you ever take off (PHAK ch 16).
Cones, concentrated at the center of the retina, give color and detail in good light; rods, out in the periphery, are far more sensitive in dim light. At night the center of your vision is effectively a blind spot, so scan by looking slightly off-center from what you want to see (PHAK ch 16).
Under the pressure of a dive, nitrogen dissolves into body tissues. As pressure drops it comes back out of solution and takes the path of least resistance — the joints, for example. Climbing to altitude after a dive is essentially a second ascent with even lower pressure, which is why the 12/24-hour wait times in the Quick Review exist (AIM 8-1-2).
Special Emphasis Areas
Examiners weave these into every task on the checkride, so know the list cold:
- Positive exchange of flight controls
- Stall/spin awareness
- Collision avoidance
- Wake turbulence avoidance (AIM 4-6-7, PHAK ch 13)
- Land and hold short operations (LAHSO) (AIM 4-3-11)
- Runway incursion avoidance (PHAK ch 13)
- CFIT awareness
- ADM and risk management (personal minimums)
- Checklist usage
- TFRs
- Special use airspace
- Aviation security (1-866-GA-SECURE)
- Single-pilot resource management (SRM)
Official ACS elementsreference
Knowledge16 elements
The applicant demonstrates understanding of:
PA.I.H.K1Symptoms, recognition, causes, effects, and corrective actions associated with aeromedical and physiological issues, including:PA.I.H.K1aa. HypoxiaPA.I.H.K1bb. HyperventilationPA.I.H.K1cc. Middle ear and sinus problemsPA.I.H.K1dd. Spatial disorientationPA.I.H.K1ee. Motion sicknessPA.I.H.K1ff. Carbon monoxide poisoningPA.I.H.K1gg. StressPA.I.H.K1hh. FatiguePA.I.H.K1ii. Dehydration and nutritionPA.I.H.K1jj. HypothermiaPA.I.H.K1kk. Optical illusionsPA.I.H.K1ll. Dissolved nitrogen in the bloodstream after scuba divesPA.I.H.K2Regulations regarding use of alcohol and drugs.PA.I.H.K3Effects of alcohol, drugs, and over-the-counter medications.PA.I.H.K4Aeronautical Decision-Making (ADM) to include using Crew Resource Management (CRM) or Single- Pilot Resource Management (SRM), as appropriate.
Risk Management4 elements
The applicant is able to identify, assess, and mitigate risk associated with:
PA.I.H.R1Aeromedical and physiological issues.PA.I.H.R2Hazardous attitudes.PA.I.H.R3Distractions, task prioritization, loss of situational awareness, or disorientation.PA.I.H.R4Confirmation and expectation bias.
Skills2 elements
The applicant exhibits the skill to:
PA.I.H.S1Associate the symptoms and effects for at least three of the conditions listed in K1a through K1l with the cause(s) and corrective action(s).PA.I.H.S2Perform self-assessment, including fitness for flight and personal minimums, for actual flight or a scenario given by the evaluator.