UA.V.E.K6: Factors affecting vision.

ACS Area V — Operations Task E: Physiology References: ACAdvisory CircularCloseFAA guidance that explains acceptable ways to comply with rules or understand FAA procedures. 107-2; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-H-8083-2, FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-H-8083-25; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-G-8082-22

Key Concepts

See-and-Avoid: Core to Visual Operations

• In the National Airspace System, approved UASUnmanned Aircraft SystemCloseAn unmanned aircraft plus its control station, communication links, and supporting components. operations outside special use airspace often depend on visual observers to provide “see-and-avoid” capability for the crew and to ensure compliance with 14 CFRCode of Federal RegulationsCloseThe federal rulebook where Part 107, Part 89, Part 48, and other aviation rules live. § 91.113. These operations are typically bounded by specific geographic areas and altitudes, coordinated with ATCAir Traffic ControlCloseThe system that manages controlled airspace, traffic flow, and aircraft separation services., and published by NOTAMNotice to Airmen / Notice to Air MissionsCloseOfficial notice about temporary conditions, hazards, or changes that can affect a flight.—each of which helps all pilots anticipate where to look and what to avoid visually. At uncontrolled airports, UASUnmanned Aircraft SystemCloseAn unmanned aircraft plus its control station, communication links, and supporting components. are advised to operate well clear of all known manned operations, and manned pilots are urged to monitor CTAFCommon Traffic Advisory FrequencyCloseThe frequency pilots use to self-announce near many non-towered airports.; at controlled airports, local ATCAir Traffic ControlCloseThe system that manages controlled airspace, traffic flow, and aircraft separation services. procedures may handle UASUnmanned Aircraft SystemCloseAn unmanned aircraft plus its control station, communication links, and supporting components. flows without requiring special procedures for manned traffic. For UASUnmanned Aircraft SystemCloseAn unmanned aircraft plus its control station, communication links, and supporting components. approved at or above FL180Flight LevelCloseAltitude expressed using a standard pressure setting, mainly relevant to higher-altitude crewed aviation., operations are conducted under IFRInstrument Flight RulesCloseRules for operating primarily by instruments. On the exam, IFR often appears in weather, traffic, and airspace context., in communication with ATCAir Traffic ControlCloseThe system that manages controlled airspace, traffic flow, and aircraft separation services., and with appropriate equipment, which changes how traffic separation is maintained and how see-and-avoid is implemented operationally. For a remote pilot, these frameworks define when you must rely on vigilant visual scanning (with or without a VOVisual ObserverCloseA person who helps the remote PIC see and avoid hazards during a drone operation.) and when system-level separation mitigates visual limitations. Always check NOTAMsNotice to Airmen / Notice to Air MissionsCloseOfficial notice about temporary conditions, hazards, or changes that can affect a flight. and coordinate as required to keep your visual scan focused where traffic is most likely to appear.^[6]

Weather and Lighting Hazards that Undermine Visual Performance

• Lightning and nearby thunderstorms can severely disrupt safe operations and attention management. Helicopter Rotorcraft Refueling (HRRHelicopter Rotorcraft RefuelingCloseA specialized refueling procedure referenced in FAA safety examples about radio silence and thunderstorm risk.) guidance prohibits HRRHelicopter Rotorcraft RefuelingCloseA specialized refueling procedure referenced in FAA safety examples about radio silence and thunderstorm risk. when electrical storms are present within 10 nautical miles, noting that lightning can travel great distances beyond the actual thunderstorm. While this procedure is helicopter-specific, the safety principle applies broadly to remote pilots: convective weather within 10 NMNautical MileCloseA distance unit used in aviation. One nautical mile is about 1.15 statute miles. signals a high-risk visual environment due to rapidly changing conditions, distractions, and potential strike hazards—reasons to pause, reassess, and, if necessary, delay flight. HRRHelicopter Rotorcraft RefuelingCloseA specialized refueling procedure referenced in FAA safety examples about radio silence and thunderstorm risk. guidance also underscores that operations of this type demand attention to weather conditions, static electricity, and fire/spill potential. For sUASSmall Unmanned Aircraft SystemCloseA small drone plus the control and communication links used to operate it., adopting conservative standoff from convective activity preserves your ability to maintain visual contact with the aircraft, the airspace, and other traffic. Treat any thunderstorm within 10 NMNautical MileCloseA distance unit used in aviation. One nautical mile is about 1.15 statute miles. as a cue to elevate caution and revalidate your operational risk controls.^[8]

Vision-Enhancing Technology: Capabilities and Limits

• Enhanced Flight Vision Systems (EFVSEnhanced Flight Vision SystemCloseA crewed-aircraft system that helps pilots see in low visibility under strict authorization rules.) illustrate how technology can assist pilots when natural vision is limited—but only within strict regulatory confines. EFVSEnhanced Flight Vision SystemCloseA crewed-aircraft system that helps pilots see in low visibility under strict authorization rules. operations to 100 feet above the touchdown zone elevation (TDZETouchdown Zone ElevationCloseThe highest runway elevation in the touchdown zone, used in instrument procedure minima.) are governed by 14 CFRCode of Federal RegulationsCloseThe federal rulebook where Part 107, Part 89, Part 48, and other aviation rules live. § 91.176(b), and such operations may not be conducted on approaches that have circling minimums. EFVSEnhanced Flight Vision SystemCloseA crewed-aircraft system that helps pilots see in low visibility under strict authorization rules. equipment used for these operations must conform to an FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes. type design approval, such as a TCType CertificateCloseFAA design approval for an aircraft, engine, propeller, or related product. or STCSupplemental Type CertificateCloseFAA approval for a major change to an aircraft or approved aviation product.. Operational authorization also matters: conducting EFVSEnhanced Flight Vision SystemCloseA crewed-aircraft system that helps pilots see in low visibility under strict authorization rules. to touchdown and rollout requires an OpSpecOperations SpecificationCloseFAA operating authorization/specification used by certain operators outside routine Part 107 use., MSpecManagement SpecificationCloseFAA authorization/specification document used by some operators, mainly outside typical Part 107 use., or LOALetter of AuthorizationCloseFormal written authorization for a specific operation, equipment use, or procedure. that specifies visibility minimums; operators under Parts 91K, 121, 125, 129, and 135 need specific authorization even for EFVSEnhanced Flight Vision SystemCloseA crewed-aircraft system that helps pilots see in low visibility under strict authorization rules. to 100 feet above the TDZETouchdown Zone ElevationCloseThe highest runway elevation in the touchdown zone, used in instrument procedure minima., while Part 91 (non‑91K) operators are not required to hold an LOALetter of AuthorizationCloseFormal written authorization for a specific operation, equipment use, or procedure. for EFVSEnhanced Flight Vision SystemCloseA crewed-aircraft system that helps pilots see in low visibility under strict authorization rules. operations. The key takeaway for remote pilots: vision-aiding tools do not waive regulatory minima or authorization requirements. If technology is used to augment visual capability, ensure it is approved for the exact operation, and understand any minima or approach limitations attached to that approval.^[2]

Sensory Cues, G-Loading, and Visual Tasking

• Pilots often judge load factor by the “feel” of seat pressure, but control pressure is not a reliable index of load factor across different aircraft designs. An accelerometer can measure Gs, but is uncommon in many training aircraft. Developing accurate perception of load factors is important because excessive maneuvering can induce high Gs, increasing stall risk and diverting attention from the visual scan you rely on for see-and-avoid. To reduce unnecessary workload and maintain visual effectiveness, confine full control inputs to speeds at or below maneuvering speed, and avoid rapid, large alternating inputs. Mastering load factor awareness helps prevent stalls from steep turns or aggressive maneuvering near the ground—scenarios where losing visual focus on traffic and terrain can quickly escalate risk.^[5][7]