Visual Scanning & Collision Avoidance

Visual scanning and collision avoidance techniques are paramount to maintain safe 'see and avoid' operations within the aviation environment.

Visual Scanning & Collision Avoidance

Introduction to Visual Scanning & Collision Avoidance

  • Incidents of aircraft impacting each other in midair or close calls demonstrate the criticality of visual scanning and collision avoidance.
  • Visual scanning and collision avoidance are terms often used interchangeably, but there are distinct differences between them.
  • Reinforce your understanding of Visual Scanning & Collision Avoidance by completing the knowledge quiz and interactive scenario, comparing your performance with the applicable Airman Certification Standards, and reviewing the topic summary before moving on.
On This Page

Help Us Grow

Enjoy CFI Notebook? A one-time donation helps us create more high-quality lessons, quizzes, scenarios, graphics, and interactive tools.

One-Time Donation
Visual Scanning & Collision Avoidance

Visual Scanning & Collision Avoidance Key Highlights

  • Visual scanning and collision avoidance are essential pilot responsibilities during all phases of flight operations.
  • Effective visual scanning techniques help pilots detect conflicting traffic, terrain, and other airborne hazards.
  • The human eye has limitations that can reduce traffic detection, especially during high workload or reduced visibility conditions.
  • Pilots should scan the sky systematically using short, overlapping visual sectors rather than continuous sweeping motions.
  • Traffic that appears stationary in the windscreen may indicate a potential collision course requiring immediate attention.
  • Blind spots, cockpit structure, weather conditions, and sun angle can interfere with visual traffic detection.
  • Radio communication, exterior lighting, and predictable flight paths improve traffic awareness and collision avoidance.
  • Aircraft equipped with traffic advisory systems and ADS-B technology provide additional situational awareness but do not replace visual scanning.
  • Pilots must comply with right-of-way rules while maintaining vigilance for other aircraft in all airspace environments.
  • Understanding visual scanning and collision avoidance improves situational awareness, traffic detection, and overall flight safety.
Visual Scanning & Collision Avoidance

Visual Scanning Versus Collision Avoidance

  • Collision Avoidance: See, Sense, Separate
  • Visual scanning is the consistent scan to avoid hazards, known or unknown, to a pilot.
  • Collision avoidance involves taking action to avoid obstacles by conducting a thorough preflight.
    • Collision avoidance involves looking for obstacles during ground reference maneuvers and conducting map studies before, during, and after flight, as well as during ground operations.
  • Note that while visual scanning requires Visual Meteorological Conditions (VMC), pilots continuously work on collision avoidance from preflight until engine shutdown.
Visual Scanning & Collision Avoidance

Visual Scanning

  • The eye can best see motion.
    • Scanning is a continuous process used by the pilot and copilot (or right-seat passenger) to cover all areas of the sky visible from the cockpit.
    • Although pilots must meet specific visual acuity requirements, the ability to read an eye chart does not ensure that one will be able to spot other aircraft efficiently.
    • The probability of spotting a potential collision threat obviously increases with the time spent looking outside the cockpit.
    • Thus, one must use timesharing and scanning techniques to efficiently maximize visual techniques, monitoring the surrounding airspace while also keeping an eye on aircraft instruments.
  • FAR 91.113(b): When in VMC, it's the pilot's responsibility to see and avoid.
  • During VMC, outside scanning should receive most of the pilot's visual attention. The FAA recommends no more than about 4 to 5 seconds on the instrument panel for every 16 seconds spent scanning outside.
  • When moving eyes from inside to outside, or vice versa, give the eyes time to adjust.
  • Vision can be affected by different levels of illumination:
    • Major factors that determine the effectiveness of vision are the level of illumination and the technique used to scan the sky for other aircraft.

    • Bright Illumination:

      • Reflected off clouds, water, or snow, and desert terrain that produces glare, resulting in eye strain
      • Excessive illumination from light reflected off the canopy, surfaces inside the aircraft, clouds, water, snow, and desert terrain can produce glare, with uncomfortable squinting, watering of the eyes, and even temporary blindness.
      • Sunglasses for protection from glare should absorb at least 85 percent of visible light (15 percent transmittance) and all colors equally (neutral transmittance), with negligible image distortion from refractive and prismatic errors.

    • Dim Illumination:

      • Small print and colors on aeronautical charts and aircraft instruments become unreadable.
        • Moreover, another aircraft must be much closer to be seen unless its navigation lights are on.

    • Dark Adaptation:

      • In darkness, vision becomes more sensitive to light, a process called dark adaptation.
      • Although complete dark adaptation requires at least 30 minutes in total darkness, a pilot can moderately adapt within 20 minutes under dim red cockpit lighting.
        • Since red light severely distorts colors, especially on aeronautical charts, and can cause serious difficulty in focusing the eyes on objects inside the aircraft, its use is advisable only where optimum outside night vision capability is necessary.
        • Even so, white cockpit lighting must be available when needed for map and instrument reading, especially under IFR (Instrument Flight Rules) conditions.
      • Impaired by exposure to cabin pressure altitudes above 5000', carbon monoxide inhaled in smoking and from exhaust fumes, deficiency of Vitamin A in the diet, and prolonged exposure to bright sunlight.
      • Bright light can destroy dark adaptation in seconds; closing one eye may help preserve it.
  • While the eyes can observe an approximate 200° arc of the horizon at one glance, only a small central area called the fovea, located at the back of the eye, can send clear, sharply focused messages to the brain.
    • All other visual information that is not processed directly through the fovea will be of less detail.
  • An aircraft at a distance of 7 miles, which appears in sharp focus within the foveal center of vision, would have to be as close as 7/10 of a mile to be recognized if it were outside of foveal vision.
    • Thus, one must use timesharing techniques to scan the surrounding airspace while monitoring instruments as efficiently as possible.
  • The scan should use short, regularly spaced eye movements of no more than about 10°, with each area observed for at least 1 second to enable detection.
  • Although horizontal back-and-forth eye movements seem preferred by most pilots, each pilot should develop the most comfortable scanning pattern and then adhere to it to ensure optimum scanning.
  • Studies show that the time a pilot spends on visual tasks inside the cabin (cockpit management/scanning) should represent at most 1/4 to 1/3 of the scan time outside, or 4 to 5 seconds on the instrument panel for every 16 seconds outside.
    • Since the brain processes sight information from left to right, pilots may find it easier to start scanning over their left shoulder and move across the windshield to the right.
  • Pilots should realize that their eyes may require several seconds to refocus when switching views between items in the cockpit and distant objects. The eyes will also tire more quickly when forced to adjust to distances immediately after close-up focus, as required for scanning the instrument panel. Eye fatigue can be reduced by looking from the instrument panel to the left wing, past the wing tip, and to the center of the first scan quadrant when beginning the exterior scan. After scanning from left to right, allow the eyes to return to the cabin along the right wing from its tip inward. Once back inside, one should automatically commence the panel scan.
  • Effective scanning also helps avoid "empty field myopia."
  • near midair collision on final approach Cessna 172

  • Barriers to Visual Scanning:

    • Windshield Conditions:

      • Dirty or bug-smeared windshields reduce outside visibility.
      • The eye will be distracted by spots on the windscreen.
      • The eye will have difficulty focusing on distant objects when there are several near objects in the way.

    • Blind Spots:

      • Pilots must move their heads to see around blind spots caused by fixed aircraft structures, such as door posts, wings, struts, etc.
      • It will be necessary at times to maneuver the aircraft, e.g., lift a wing, to facilitate seeing.
      • Pilots must ensure that curtains and other cockpit objects, such as maps on the glare shield, are removed and stowed during flight.

    • Visibility Conditions:

      • Smoke, haze, dust, rain, and glare from the sun reduce your ability to detect objects or birds.
      • Pilots can mitigate this by using visors [Amazon] or sunglasses [Amazon].

    • The Pilot:

      • Eyes are only as good as they are.
      • Age and fatigue all take their toll.
  • Side-to-Side Scan Pattern
    Side-to-Side Scan Pattern
  • Middle-to-Side Scan Pattern
    Middle-to-Side Scan Pattern
  • Scanning
    Scanning

  • Visual Scanning Patterns:

    • Follow these basic principles:
      1. Look outside the airplane to see where you are going.
      2. Look at the aircraft with respect to the horizon to determine the relative altitude.
        • Use the horizon as a reference point:
          • If an aircraft is above the horizon, it's probably above you.
          • If an aircraft is below the horizon, it's probably below you.
          • If an aircraft is level with the horizon, it's at your altitude.
          • Any aircraft that appears to have no relative motion and stays in one scan quadrant is likely to be on a collision course.
            • Also, if a target shows no lateral or vertical motion but increases in size, take evasive action.
            • Waiting for the aircraft to change in size could prove costly.
      3. Look inside the aircraft at the instrument panel to check for proper power settings, flight instrument readings, and any signs of engine malfunction.
  • Side-to-Side Scan Pattern
    Side-to-Side Scan Pattern
  • Middle-to-Side Scan Pattern
    Middle-to-Side Scan Pattern

  • Before Takeoff:

    • Before taxiing onto a runway or landing area in preparation for takeoff, pilots should scan the approach areas for possible landing traffic and execute the appropriate steering maneuvers to ensure a clear view.

  • Climbs and Descents:

    • During climbs and descents in conditions that permit visual detection of traffic, make gentle banks left and right often enough to continuously scan the surrounding airspace.

  • Straight and Level:

    • During sustained straight-and-level flight in conditions that permit visual detection of traffic, periodically use clearing procedures to maintain an effective scan.
    • Scan from left to right or right to left using a consistent pattern.

  • Turns:

    • High Wing: Momentarily raise the wing in the direction of the turn to look for traffic.
    • Low Wing: Lower the wing in the direction of turn and scan all the way across the turn, both forward and in the direction of the turn.

  • Traffic Pattern:

    • Entries into traffic patterns while descending create specific collision hazards and should be avoided.
    • Concentrate your scan mostly on the side of the runway that the pattern is on, as you would expect most traffic to be there.
      • The tower should give you situational awareness of potential hazardous traffic.
      • Remember, traffic, especially at an uncontrolled field, could be anywhere.
    • Entry at a 45° angle or on an extended leg (whichever is most practical) will provide the best view of the pattern.

  • VFR in Congested Areas:

    • A high percentage of near-midair collisions occur below 8,000 feet AGL and within 30 miles of an airport.
    • Maintain extra vigilance in these areas and monitor an appropriate control frequency. When radar services are available, VFR pilots may request traffic advisories on a workload-permitting basis.

  • Traffic at VOR Sites:

    • All operators should emphasize the need for sustained vigilance in the vicinity of VORs (Very High Frequency Omnidirectional Ranges) and airway intersections due to the convergence of traffic.

  • Training Operations:

    • Operators of pilot training programs should adopt the following practices:
      • Pilots undergoing flight instruction at all levels should be requested to verbalize clearing procedures (call out "clear" left, right, above, or below) to instill and sustain the habit of vigilance during maneuvering.
      • Appropriate clearing procedures should precede the execution of all turns, including chandelles, lazy eights, stalls, slow flight, climbs, straight and level, spins, and other combination maneuvers.

  • Scanning Techniques for Traffic Avoidance:

    • Pilots must be aware of the limitations inherent in the visual scanning process. These limitations may include: [//]
      • Reduced scan frequency due to concentration on flight instruments or tablets and distraction from passengers.
      • Blind spots related to high-wing and low-wing aircraft, in addition to windshield posts and sun visors.
      • Prevailing weather conditions, including reduced visibility and the position of the sun.
      • The attitude of the aircraft will create additional blind spots.
      • The physical limitations of the human eye, including the time required to (re)focus on near and far objects (from the instruments to the horizon), empty field myopia, narrow field of vision, and atmospheric lighting, all affect our ability to detect another aircraft.
    • Best practices to see and avoid:
      • ADS-B In is an effective system to help pilots see and avoid other aircraft. If equipped with ADS-B In, it is crucial to understand its features and how to use it properly. Many units provide visual and/or audio alerts to supplement the system's traffic display. Pilots should incorporate the traffic display into their routine traffic scan to stay aware of nearby aircraft. Before entering or crossing any runway, ADS-B In can give an advanced indication of arriving aircraft and aircraft in the traffic pattern. Systems incorporating a traffic-alerting feature can help minimize the pilot's inclination to fixate on the display. Refer to 4-5-7e, ADS-B Limitations.
      • Understand the limitations of ADS-B (Automatic Dependent Surveillance-Broadcast) In. In certain airspace, not all aircraft will be equipped with ADS-B Out or transponders and will not be visible on your ADS-B In display.
      • Limit the time you spend focusing on flight instruments or tablets.
      • Develop a strategic approach to scanning for traffic. Scan the entire sky and avoid focusing straight ahead.
  • Scanning
    Scanning
Visual Scanning & Collision Avoidance

Visual Separation

  • Visual separation is a means employed by ATC (Air Traffic Control) to separate aircraft in terminal areas and en route airspace in the NAS (National Airspace System).
  • There are two methods employed to effect this separation:
    • The tower controller sees the aircraft involved and issues instructions, as necessary, to ensure that the aircraft avoid each other.
    • A pilot sees the other aircraft involved and, upon instructions from the controller, maneuvers to provide separation by avoiding it.
      • When pilots accept responsibility for maintaining visual separation, they must maintain constant visual surveillance and not pass the other aircraft until it is no longer a factor.
      • Traffic is no longer a factor when, during the approach phase, the other aircraft is in the landing phase of flight or executes a missed approach.
      • Traffic is also not a factor during departure or en route, when the other aircraft turns away or is on a diverging course.
  • A pilot's acceptance of instructions to follow another aircraft or provide visual separation from it acknowledges that the pilot will maneuver the aircraft as necessary to avoid the other aircraft or maintain in-trail separation.
    • In operations conducted behind heavy aircraft, or when a small aircraft follows a B757 or other large aircraft, the pilot is responsible for ensuring wake turbulence separation upon acceptance.
      • Visual separation is prohibited behind super aircraft.
    • When a controller instructs a pilot to follow another aircraft or maintain visual separation, the pilot should promptly notify the controller if they lose sight of the other aircraft or cannot accept responsibility for the separation for any reason.
  • Scanning the sky for other aircraft is a critical factor in collision avoidance. Pilots and copilots (or the right-seat passengers) should continuously scan to cover all areas of the sky visible from the cockpit. Pilots must develop an effective scanning technique that maximizes their visual capabilities. The likelihood of spotting a potential collision threat increases directly with more time spent looking outside the aircraft. One must use timesharing techniques to scan the surrounding airspace while monitoring instruments effectively.
  • Although many pilots prefer horizontal back-and-forth scanning, each pilot should develop a scanning pattern that is not only comfortable but also ensures optimum effectiveness. Pilots should remember, however, that they have a regulatory responsibility (14 CFR (Code of Federal Regulations) Section 91.113(a)) to see and avoid other aircraft when weather conditions permit.

  • Pilot:

    • Acceptance of instructions to follow another aircraft or to provide visual separation from it is an acknowledgment that the pilot will maneuver the aircraft as necessary to avoid the other aircraft or to maintain in-trail separation. Pilots are responsible for maintaining visual separation until flight paths (altitudes and/or courses) diverge.
    • If instructed by ATC to follow another aircraft or to provide visual separation from it, promptly notify the controller if you lose sight of that aircraft, are unable to maintain continued visual contact with it, or cannot accept the responsibility for your own separation for any reason.
    • The pilot also accepts responsibility for wake turbulence separation under these conditions.

  • Controller:

    • Controllers apply visual separation only when:
      • Within the terminal area, when a controller has both aircraft in sight or by instructing a pilot who sees the other aircraft to maintain visual separation from it.
      • Pilots are responsible for maintaining visual separation until flight paths (altitudes and/or courses) diverge.
      • Within en route airspace, when aircraft are on opposite courses and one pilot reports having seen the other aircraft and that the aircraft have passed each other.
Visual Scanning & Collision Avoidance

Situational Awareness

  • Situational awareness is a skill necessary for both ground and in-flight operations.
  • Knowing where you will be and where other traffic will be is essential.
  • Recognize High Hazard Areas:
    • Airways, especially near VORs and Class B, Class C, Class D, and Class E surface areas, are places where aircraft tend to cluster.
    • Remember, most collisions occur on days when the weather is good.
      • Being in a "radar environment" still requires vigilance to avoid collisions.
  • Listening and looking: the Good Senses.
  • All available information (FAR 91.103).
  • "Head's down" decreases situational awareness, so minimize it as much as possible.
  • Common Problems: When are you doing checklists? Do you have taxi diagrams when you land? Are your radios preset when you are "in range?" Do you ensure you have weather before you land?
Visual Scanning & Collision Avoidance

Additional Methods/Tools

  • Use radar services, TCAS (Traffic Alert and Collision Avoidance System), ADS-B, GPS (Global Positioning System), and Mode S/TIS (Traffic Information Service).
  • ATC facilities often provide radar traffic advisories on a workload-permitting basis.
    • Use this support whenever possible or when required.
  • FAR 91.126(b) - Operating near Airports in Class G Airspace - When approaching to land at an airport without an operating control tower... each pilot of an airplane must make all turns of that airplane to the left [unless otherwise designated].
  • FAR 91.127(a) - Operating near Airports in Class E Airspace - When operating in the vicinity of an airport in Class E airspace, comply with FAR 91.126.
  • Additional tips include verifying ATC calls are accurate, turning on lights, and questioning any conflict or confusion.
Visual Scanning & Collision Avoidance

Judgment Aspects of Collision Avoidance

  • Remember cruising altitudes based on direction.
  • The decision to climb, descend, or turn is a matter of personal judgment, but one should anticipate that the other pilot may also be making a quick maneuver. Watch the other aircraft during the maneuver and resume scanning immediately since there may be other aircraft in the area.
  • Recognize High Hazard Areas:
    • Airways, especially near VORs and Class B, Class C, Class D, and Class E surface areas, are places where aircraft tend to cluster.
    • Remember, most collisions occur during days when the weather is good. Being in a "radar environment" still requires vigilance to avoid collisions.

  • Aircraft Lighting:

    • Operation Lights On:

      • Day or night, the use of exterior lights can significantly increase the conspicuity of any aircraft (cheap insurance!).
      • Keep interior lights low at night.
      • Operate installed anticollision lights during day and night operations.
        • The pilot in command may turn them off when operating conditions make doing so safer; turn off supplementary strobes when cloud reflections adversely affect vision.
      • Turn on the rotating beacon whenever the engine is running.
      • Use of position lights at night, FAR 91.209.
      • The FAA recommends using landing lights below 10,000 feet, day or night, especially within 10 miles of an airport, in reduced visibility, or where flocks of birds may be expected.
      • The goal is to be as visible as possible.

  • Air Traffic Control Support:

    • ATC facilities often provide radar traffic advisories on a workload-permitting basis.
    • Flight through Class C and Class D airspace requires communication with ATC.
    • Use this support whenever possible or when required.
    • Provides radar traffic information to radar-identified aircraft operating outside positive control airspace on a workload-permitting basis.
    • Additionally, controllers may issue safety alerts to aircraft under their control if they are aware that the aircraft is at an altitude believed to place the aircraft in unsafe proximity to terrain, obstructions, or other aircraft.
    • Some pilots have questioned ATC upon receiving an amended clearance, requested "traffic information," and were at a loss when the reply indicated "no traffic report."
      • In such cases, the controller has taken action to prevent a traffic conflict that would have occurred at a distant point.
  • The eye requires time to adjust to looking at objects of different colors and at various distances.
  • An object seen in one eye but obscured from another may cause us not to "accept" it.
  • Blossom effect: objects at a distance appear stationary but will suddenly bloom into a huge mass when they get close.
Visual Scanning & Collision Avoidance

Communications Best Practices

  • ICS: "clear left, clear right" as appropriate
Visual Scanning & Collision Avoidance

Obstructions to Flight

  • Communication Antennas
    Communication Antennas
  • Although the hazard may seem obvious, controlled flight into terrain remains a leading cause of aviation accidents.
  • Terrain and obstacles along the route of flight must be avoided either laterally or vertically
  • Additionally, a brief study of the map should highlight hazards should the pilot chose to alter the route, in flight
  • Many structures exist that could significantly affect the safety of your flight when operating below 500' AGL and particularly below 200' AGL, despite FAR 91.119 allowing flight below 500' when over sparsely populated areas or open water.
  • Obstacles that extend more than 200 feet AGL are typically shown on sectional charts unless they are within the yellow tint of a city.
  • At and below 200 feet AGL there are numerous power lines, antenna towers, etc., that are not marked and lighted and/or charted as obstructions and, therefore, may not be seen in time to avoid a collision.
  • The FAA typically issues Notices to Airmen (NOTAMs) for unlit structures, but pilots must stay vigilant in case the FAA has not received outage notifications.
    • Additionally, new obstructions may not be on current charts because the information was not received prior to the FAA publishing the chart.

  • Antenna Towers:

    • Numerous skeletal structures, such as radio and television antenna towers, exceed 1,000' or 2,000' AGL. []
    • Guy wires support most skeletal structures, but they are challenging to see in good weather and can become invisible at dusk or during periods of reduced visibility.
    • These wires can extend about 1,500 feet horizontally from a structure; therefore, all skeletal structures should be avoided horizontally by at least 2,000 feet.
  • Communication Antennas
    Communication Antennas

  • Overhead Wires:

    • Transmission and utility lines often span areas used for runway approaches and natural flyways, such as lakes, rivers, gorges, and canyons. They also cross other landmarks pilots frequently follow, such as highways, railroad tracks, and other major transportation routes.
    • As with antenna towers, these power transmission and/or utility lines and the supporting structures of these lines may not always be readily visible.
      • The wires may be virtually impossible to see under certain conditions.
      • Spherical markers may be used to identify overhead wires and catenary transmission lines and may be lighted.
    • In some locations, the supporting structures of overhead transmission lines are equipped with unique sequence flashing white strobe light systems to indicate that there are wires between the structures.
      • The flash sequence for the wire support structures will be middle, top, and bottom with all lights on the same level flashing simultaneously.
      • However, not all power transmission and/or utility lines require notice to the FAA as they do not exceed 200 feet AGL or meet the obstruction standard of 14 CFR Part 77 and, therefore, are not marked and/or lighted.
    • All pilots are cautioned to remain extremely vigilant for power transmission and/or utility lines and their supporting structures when following natural flyways or during the approach and landing phase.
      • This is particularly important for seaplane and/or float equipped aircraft when landing on, or departing from, unfamiliar lakes or rivers.
  • Sectional Depiction of Wind Farms
    Sectional Depiction of Wind Farms

  • Wind Turbines:

    • Wind turbines are becoming increasingly prevalent as a component in the shift to renewable energy.
    • Wind turbines are typically below 500 feet, but some may be significantly higher, even encroaching into the 700 foot AGL floor of Class E airspace.
    • The locations of wind turbine farms have also expanded to areas more commonly flown by VFR pilots and to all regions of the United States.
    • VFR pilots should be aware that many wind turbines are exceeding 499 feet AGL in height, which may affect minimum safe VFR altitudes in uncontrolled airspace. []
    • Pilots are cautioned to maintain appropriate safe distance (laterally, vertically, or both).
    • Wind turbines are typically charted on Visual Flight Rules (VFR) Sectional Charts and/or Terminal Area Charts.
    • For a description of how wind turbines and wind turbine farms are charted, refer to the FAA Aeronautical Chart User's Guide.
    • Wind turbines are normally painted white or light gray to improve daytime conspicuity.
    • They are typically lit with medium−intensity, flashing red lights, placed as high as possible on the turbine nacelle (not the blade tips), that should be synchronized to flash together; however, not all wind turbine units within a farm need to be lighted, depending on their location and height.
    • Sometimes, only the perimeter of the wind turbine farm and an arrangement of interior wind turbines are lit.
    • Some wind turbine farms use Aircraft Detection Lighting Systems (ADLS), which are proximity sensor−based systems designed to detect aircraft as they approach the obstruction.
    • This system automatically activates the appropriate obstruction lights until they are no longer needed based on the position of the transiting aircraft.
    • This technology reduces the impact of nighttime lighting on nearby communities and migratory birds and extends the life expectancy of the obstruction lights.
    • For more information on how obstructions such as wind turbines are marked and lighted, refer to Advisory Circular 70/7460−1, Obstruction Marking and Lighting.
    • Pilots should be aware that wind turbines in motion could result in limitations of air traffic services in the vicinity of the wind turbine farms.
    • Turbines or groups of turbines (1 out of 3 lights must illuminate) have red flashing lights placed on top of the turbine nacelle (note the blade is higher).
    • Additionally, wind farms can produce reflectivity, producing returns on Doppler radar.
    • Sectional charts depict wind farms with a boxed number indicating the maximum elevation figure.
  • Sectional Depiction of Wind Farms
    Sectional Depiction of Wind Farms

  • Meteorological Evaluation Towers:

    • MET towers are used by wind-energy companies to evaluate potential wind-turbine sites.
    • These structures are portable, erected in a matter of hours, installed with guyed wires, and constructed from a galvanized material often making them difficult to see in certain atmospheric conditions.
    • Markings for these towers include alternating bands of aviation orange and white paint, and high−visibility sleeves installed on the outer guy wires.
    • However, not all MET towers follow these guidelines, and pilots should be vigilant when flying at low altitude in remote or rural areas.
  • Key West Balloon Hazard
    Key West Balloon Hazard

  • Unmanned Balloons:

    • The majority of unmanned free balloons currently in operation have either a suspension device extending below them, to which the payload or instrument package is attached, a trailing wire antenna, or both. []
    • Good judgment on the part of the pilot dictates that aircraft should remain well clear of all unmanned free balloons, and pilots should avoid flight below balloons at all times.
    • The FAA urges pilots to report any sighted unmanned free balloons to the nearest FAA ground facility to help ATC identify and track them in the airspace.
    • Key West Balloon Hazard
      Key West Balloon Hazard

  • Other Objects/Structures:

    • There are other objects or structures that could adversely affect your flight such as temporary construction cranes near an airport, newly constructed buildings, new towers, etc.
    • Many of these structures do not meet charting requirements or may not yet be charted because of the charting cycle.
    • Some structures do not require obstruction marking and/or lighting, and some may not be marked and lighted even though the FAA recommended it.
    • VFR pilots should carefully review NOTAMs for temporary or permanent obstructions along the planned route of flight during their preflight preparations.
    • Particular emphasis should be given to obstructions in the vicinity of the approach and departure ends of the runway complex or any other areas where flight below 500 feet AGL is planned or likely to occur.
Visual Scanning & Collision Avoidance

Visual Scanning & Collision Avoidance Lessons & Case Studies

Visual Scanning & Collision Avoidance

Visual Scanning & Collision Avoidance Interactive Scenario

Illustration of effective scanning from the center toward side sectors.

The Saturated Training Area

Manage a VFR (Visual Flight Rules) training flight through haze, blind spots, traffic-display limitations, head-on and converging conflicts, glare, and a crowded airport arrival.

15 DecisionsScenario-Based TrainingVisual Scanning and Collision AvoidanceConsequence-BasedRetry and Debrief
Decision 1
0%

Scenario Complete

Visual Scanning & Collision Avoidance

Visual Scanning & Collision Avoidance Knowledge Check

Choose the knowledge check that matches your current training for Visual Scanning & Collision Avoidance.

Private Pilot quiz illustration Private Pilot

PPL knowledge check

Core Knowledge Review

Review foundational knowledge, key concepts, and practical considerations. Topic: Visual Scanning & Collision Avoidance.

  • Immediate feedback
  • Answer explanations
  • Account progress tracking

Why Take a Quiz?

Quizzes reinforce key concepts, identify knowledge gaps, and build confidence for real-world decisions. Quiz material is representative of the information provided here and is not based on or sourced from the Federal Aviation Administration test bank.

Visual Scanning & Collision Avoidance

Visual Scanning & Collision Avoidance Conclusion

  • Collision Avoidance Checklist
    Collision Avoidance Checklist
  • Visual scanning and collision avoidance are two responsibilities of the pilot in command.
  • According to NTSB statistics, midair collisions are likely to happen:
    • VFR, daylight, weekend.
    • Below 3,000' AGL at uncontrolled airports within 10nm, 8,000' AGL within 25nm.
    • Great weather.
    • All pilot skill levels.
    • Pleasure flight, no flight plan.
    • Within 5 miles of towered and 10 miles of non-tower airports.
    • Transition to/from the traffic pattern (crossing or overtaking maneuvers).
    • Primarily in the traffic pattern.
  • Constantly checking for traffic should be a habit - a way of life.
  • The pilot's vision and techniques to scan for other aircraft are paramount.
    • FAR 91.113(b) "See and Avoid" ...When weather conditions permit, pilots must maintain vigilance to see and avoid other aircraft, whether operating under instrument or visual flight rules.
  • Pay attention to other traffic at all times, but especially when the risk for midair is statistically higher:
    • Within five nautical miles of an airport;
    • In daylight visual flight rules conditions, and;
    • At or below 3,000 feet above ground level (AGL).
  • Additional tips include verifying ATC calls are accurate, turning on lights, and questioning any conflict or confusion.
  • To mitigate the limits of human performance, the aviation industry (endorsed by the FAA) built additional methods/tools for pilots to augment visual scanning.
  • Your eyes are not perfect and can play tricks on you, especially at night and in instrument meteorological conditions.
  • Visual scanning and collision avoidance are part of every flight, from engine start to engine shutdown. []
  • Pilots should be familiar with rules on right-of-way, so if an aircraft is on an obvious collision course, one can take immediate evasive action, preferably in compliance with applicable Federal Aviation Regulations (FAR).
  • When weather conditions permit, during the time an IFR flight is operating, it is the direct responsibility of the pilot to avoid other aircraft since VFR flights may be operating in the same area without ATC's knowledge.
    • Traffic clearances provide standard separation only between IFR flights.
  • It is a constant task, and the more eyes, the better, so utilize crew resource management as part of every flight.
  • Other objects or structures could adversely affect your flight, such as construction cranes near an airport, newly constructed buildings, and new towers.
  • Many of these structures fail to meet charting requirements or have not yet appeared on charts due to the charting cycle.
  • Some structures do not require obstruction marking and/or lighting, and some may not be marked and lighted even though the FAA recommends it.
  • See also:
  • Remember your minimum safe altitudes.
  • The AOPA offers a collision avoidance safety spotlight course.
  • Collision Avoidance Checklist
    Collision Avoidance Checklist
  • Still looking for something? Continue searching:
Visual Scanning & Collision Avoidance

Visual Scanning & Collision Avoidance References