9.0 Physiology and Maintenance Part 107 Practice Quiz

• A. Fix the gaze at the sUAS at all times; peripheral vision will detect any manned aircraft that enters the field of view without needing to actively scan
• B. Sweep the eyes continuously in a smooth, flowing motion from left to right across the entire field of view at a steady rate
• C. Focus exclusively on the area directly beneath the sUAS flight path because manned aircraft always approach from below when conflicting with sUAS altitude bands
• D. Use a systematic block scanning technique, move the eyes in a series of short, deliberate shifts to successive 10-to-15 degree sectors, pausing briefly in each sector to allow the eye to focus

The most effective visual scanning technique for detecting traffic uses a systematic block scan with short, deliberate eye movements of 10-15 degrees and a brief pause (about 1 second) in each sector; this allows the eye to focus and process information in each area before moving to the next, maximizing the probability of detecting conflicting traffic.

• A. Carbon monoxide (CO) from the gasoline generator, which displaces oxygen in the blood's hemoglobin and impairs brain function even at low concentrations
• B. Diesel exhaust particulates from vehicles entering the structure, which irritate the bronchial passages and reduce oxygen exchange in the lungs
• C. Ozone produced by the generator's electrical system, which at high concentrations causes respiratory irritation but not the described neurological symptoms
• D. Nitrogen dioxide from exhaust, which causes delayed pulmonary edema but does not produce immediate headache or cognitive impairment in the described timeframe

Carbon monoxide is an odorless, colorless gas produced by incomplete combustion in gasoline engines; CO binds to hemoglobin approximately 200 times more readily than oxygen, preventing oxygen delivery to the brain; early symptoms include headache, confusion, difficulty concentrating, and impaired judgment, all consistent with the described scenario; the pilot must immediately move to fresh air.

• A. The lens of the eye focuses most accurately on objects located approximately 15 degrees off-center; direct viewing causes focal blur from lens curvature limitations at night
• B. Cone cells concentrated at the fovea provide best color and detail vision in daylight but are insensitive in low light; rod cells distributed around the periphery of the retina are more sensitive to dim light and work better when the image falls off-center
• C. The optic nerve is located at the center of the retina and creates a natural blind spot directly in front of the viewer; off-center viewing avoids this blind spot in all lighting conditions
• D. Off-center viewing activates the parasympathetic nervous system and causes the pupil to dilate more completely, allowing more light to enter the eye for a brighter image

The retina contains two types of photoreceptors: cones, concentrated in the fovea (center), provide sharp color vision in daylight (photopic vision); rods, distributed in the peripheral retina, are far more sensitive to low levels of light and are used in night (scotopic) vision; by looking slightly off-center, the image falls on the rod-rich peripheral retina, making dim objects like aircraft lights more visible in darkness.

• A. The sUAS flight controller's attitude indicator and telemetry data displayed on the ground control station, which reflects the aircraft's actual orientation
• B. Vestibular (inner ear) sense of balance, which accurately detects aircraft attitude changes even when visual cues are reduced or absent
• C. Kinesthetic sense (feel of the controls), which provides precise attitude feedback through the resistance felt in the control sticks during maneuvering
• D. Peripheral vision, which is more accurate than central vision for detecting attitude deviations in reduced visibility conditions

The sUAS's onboard sensors (IMU, gyroscopes, barometer) feed the flight controller's attitude and telemetry data, which is displayed on the ground control station; this instrumentation is not subject to spatial disorientation and provides the accurate reference when visual cues are lost; the pilot must trust the instruments over subjective sensations.

• A. Wear a surgical face mask rated N95 or higher, which filters CO molecules from the air before they can be inhaled
• B. Conduct operations during the hottest part of the day because heat disperses CO and reduces its concentration at breathing height
• C. Position operations upwind of combustion sources and use a portable battery-powered CO detector/alarm at the operator's position
• D. Limit operations to no more than 15 minutes at a time near any combustion source, then relocate 50 feet away for at least 5 minutes

Positioning upwind of combustion sources reduces exposure by keeping the operator in cleaner air; a portable CO detector/alarm provides an objective early warning before symptoms develop, since CO is odorless and colorless and cannot be detected by the human senses alone.

• A. Log the anomaly in the aircraft maintenance record and have the gimbal inspected and repaired before the next flight to confirm it is in a condition for safe operation
• B. Ignore the anomaly because the camera gimbal is a payload accessory and is not part of the aircraft's airworthiness determination under Part 107
• C. Power cycle the aircraft three times; if the grinding sound does not recur, document it as a transient anomaly and clear the aircraft for the next mission without further action
• D. Continue using the aircraft for the next mission with the grinding gimbal because the problem only affects payload quality, not flight safety

Logging the anomaly immediately after discovery preserves accurate information while the details are fresh; the gimbal should be inspected and repaired before the next flight because a mechanical failure in the gimbal system during flight could affect the aircraft's aerodynamic stability, CG, or payload security under 107.15.

• A. The rough motor is functioning normally; slight resistance in one position is caused by the motor's magnetic detent positions and is expected behavior for all brushless motors
• B. The rough motor has a contaminated rotor; spray electrical contact cleaner into the motor gap and re-test; if the roughness clears, the motor is safe to fly
• C. The resistance indicates the motor stator is magnetized too strongly; the pilot should degauss the motor by spinning it rapidly by hand multiple times before the flight
• D. The rough motor likely has a damaged or worn bearing; continued operation risks bearing seizure in flight, causing that motor to stop producing thrust and destabilizing the aircraft

Rough, grinding resistance during manual spin of a brushless motor indicates bearing damage or contamination; a motor with a failing bearing can seize in flight, causing sudden loss of thrust on that motor, which in a quadcopter typically causes loss of control; the motor should be inspected and the bearing replaced or the motor replaced before flight.

• A. Fixation error, the pilot's eyes are physically unable to move faster than the angular velocity of the distant helicopter, making detection impossible without optical aids
• B. Empty field myopia, in a featureless visual environment the eyes relax to a resting focal point of approximately 1 to 2 meters rather than focusing at optical infinity, reducing the ability to detect distant objects
• C. Night blindness, the bright blue sky activates the rod suppression reflex, reducing the pilot's ability to detect moving objects in the field of view
• D. Photopic adaptation failure, bright blue sky triggers an overproduction of cone pigments that bleaches out the ability to detect fine contrast differences at range

Empty field myopia occurs when there are no visual cues at varying distances in the field of view; without texture or depth information, the eyes relax to their resting focus distance of approximately 1-2 meters rather than focusing at optical infinity; objects beyond that focal distance, such as a distant aircraft, are slightly blurred and much harder to detect even with good visual acuity under normal conditions.