Physiological effects — Part 107 practice questions

10 practice questions on physiological effects from the FAA remote pilot knowledge test, each with the correct answer and why it is correct.

1. 01

   What do the letters of the IMSAFE checklist stand for?

   • Illness, Medication, Stress, Alcohol, Fatigue, EmotionCorrect
   • Inspection, Maintenance, Startup, Airspace, Flight, Egress
   • Intent, Mission, Site, Airspace, Fuel, Equipment
   • Illness, Motivation, Skill, Attitude, Fitness, Experience
   Why

   Illness, Medication, Stress, Alcohol, Fatigue, Emotion. It is the one preflight check aimed at the pilot rather than the aircraft, and the two most easily rationalised items sit in the middle: stress and fatigue rarely feel disqualifying at the time, which is why they are on a list rather than left to judgement.

2. 02

   A remote pilot working outdoors on a hot day develops a headache, dizziness, and drowsiness. What should be suspected first?

   • Dehydration and heat stressCorrect
   • Hyperventilation caused by the altitude of the operation
   • Carbon monoxide poisoning from the aircraft's motors
   • Middle ear discomfort from pressure changes
   Why

   Headache, dizziness and drowsiness after a stretch outdoors in heat is the standard dehydration picture, and it arrives well before thirst becomes insistent. The other candidates need conditions that are not present here — a remote pilot stands on the ground beside an electric aircraft, not in a cockpit at altitude.

3. 03

   A remote pilot takes an over-the-counter antihistamine that lists drowsiness as a side effect. What is the appropriate decision?

   • Do not fly, because both the medication and the underlying illness can impair performanceCorrect
   • Fly, because only prescription medication is restricted
   • Fly, provided a visual observer is present
   • Fly after waiting 8 hours, the same interval that applies to alcohol
   Why

   Two reasons not to fly, either sufficient: the drowsiness the medication causes, and whatever condition made it necessary. Over-the-counter status is not a safety rating — many of these are more impairing than the illness. The 8-hour alcohol interval is specific to alcohol and does not transfer.

4. 04

   Which cells in the eye are responsible for vision in low light, and where are they concentrated?

   • Rods, concentrated outside the centre of the retinaCorrect
   • Cones, concentrated at the centre of the retina
   • Rods, concentrated at the centre of the retina
   • Cones, concentrated outside the centre of the retina
   Why

   Rods handle low light and sit away from the centre of the retina; cones handle colour and detail in good light and cluster at the centre. That geometry has a direct operational consequence at night — the most sensitive part of your vision is not the part you point at things.

5. 05

   Approximately how long does it take for the eyes to adapt fully to darkness?

   • About 30 minutesCorrect
   • About 2 minutes
   • About 10 seconds
   • About 2 hours
   Why

   About 30 minutes to build, and a moment of bright white light to lose. That asymmetry is the whole reason for the advice to avoid white lights before and during a night operation — checking a phone screen at full brightness costs adaptation that takes another half hour to earn back.

6. 06

   How does stress most commonly affect a remote pilot's performance?

   • It narrows attention and degrades decision-making, so information is missedCorrect
   • It sharpens attention, which makes flying safer
   • It affects only pilots who are also fatigued
   • It has no measurable effect on unmanned operations
   Why

   Stress narrows attention onto whatever feels most urgent, which is rarely the thing about to cause the accident. Information that would ordinarily be noticed simply is not. It needs no help from fatigue to do this, and an unmanned operation is no more immune than a manned one — the pilot is the same equipment either way.

7. 07

   What is off-center viewing and why is it used at night?

   • Looking slightly to the side of an object, so its image falls on the light-sensitive rodsCorrect
   • Looking directly at an object, so its image falls on the colour-sensitive cones
   • Scanning the horizon in one continuous sweep to cover more sky
   • Closing one eye to preserve its dark adaptation
   Why

   Looking slightly to one side of an object puts its image on the rods rather than the cone-packed centre, where at night it may simply vanish. The technique includes shifting the gaze every few seconds, because rods fade on a steady image and a stationary stare loses the object again.

8. 08

   What is the recommended response to symptoms of hyperventilation?

   • Consciously slow the rate of breathingCorrect
   • Breathe more rapidly to restore oxygen levels
   • Drink cold water quickly
   • Lie down and hold the breath for as long as possible
   Why

   The problem is too little carbon dioxide rather than too little oxygen, so the fix is to slow the breathing down and let it rebuild. Breathing harder is the instinct and it makes things worse. Once the rate is under control the light-headedness and tingling subside on their own.

9. 09

   Why is fatigue considered particularly dangerous for a remote pilot?

   • It degrades performance and judgment while often going unnoticed by the affected personCorrect
   • It produces obvious physical symptoms that are easy to identify in oneself
   • It affects only night operations
   • Its effects are fully reversed by caffeine
   Why

   Because the faculty fatigue degrades first is the one that would otherwise notice it. Judgment and reaction time fall away while the pilot's confidence in both stays intact, which is what makes it more treacherous than an impairment that announces itself. Caffeine masks the symptom; it does not restore the capability.

10. 10

    What blood alcohol concentration disqualifies a person from acting as a remote pilot in command?

    • 0.04 or greaterCorrect
    • 0.08 or greater
    • 0.02 or greater
    • 0.10 or greater
    Why

    0.04, which is half the usual driving limit — flying is held to a stricter standard than driving. It is also only one of three independent disqualifiers: the 8-hour rule and being under the influence each stand on their own, so a reading below 0.04 settles nothing by itself.