Visual Scanning and Collision Avoidance

Objective: The student will be introduced to visual scanning techniques and collision avoidance. The student will be able introduced to the sensory systems and illusions associated with them.

Completion Standards: The student will be able to explain a visual scanning technique and what they are looking for while scanning. The student will also be able to explain the sensory systems and some of the illusions associated with them.

References: PHAK Ch 17, AC 90-48d and FAR/AIM 91.113

Equipment: White Board and markers, iPad/ computer 

IP’s Actions:

• Assess student

• State the objective and completion standards

• Writes down references

• Provide attention getter

• Present content

• Assessment

• Assign Homework

SP’s Actions:

• Take notes

• Ask Questions

Introduction: 

Attention gorilla test  https://youtu.be/IGQmdoK_ZfY

Motivation: Scanning the area around you is beneficial, not only to see what’s around you but it helps to recognize things when they are thrown toward you. When flying there are times you will want to look for other planes so you don’t get in there way and so they don’t get in yours.

Overview:

1. Relationship between a pilot’s physical condition and vision.

2. Environmental conditions that degrade vision.

3. Vestibular and visual illusions.

4. “See and avoid” concept.

5. Proper visual scanning procedure.

6. Relationship between poor visual scanning habits and

increased collision risk.

7. Proper clearing procedures.

8. Importance of knowing aircraft blind spots.

9. Relationship between aircraft speed differential and

collision risk.

10. Situations that involve the greatest collision risk.

Content:

Relationship between a pilot’s physical condition and vision

5 senses: Ask student to state the 5 senses 

1. Seeing

2. Feeling

3. Touch

4. Smell

5. Hearing

Sensory systems:

Vestibular system— The inner ear that sense the way we are balanced 

Somatosensory system— nerves in the skin, muscles, and joints that, along with hearing, sense position based on gravity, feeling, and sound  

Visual system— Eyes

Vision In Flight

Mention how eyes are most used

Anatomy of the Eye

Explain cones and rods/ what they are and what are they for

Vision types: Photopic Vision, Mesopic Vision, and Scotopic Vision

1. Photopic vision

   1. Seeing color and fine detail

   2. High levels of light Bright light like during the day

2. Mesopic Vision

   1. Combination of rods and cones and is experienced at dawn, dusk, and during full moonlight.

   2. Medium/Low levels of light dangerous time for vision

3. Scotopic Vision

   1. Cones become ineffective, resulting in poor resolution of detail.

   2. Low level of light

Central blind spot

• Optic nerve (center on eye) has a total absence of cones and rods

• Essentially has a blind spot

Environmental conditions that degrade vision

Empty-Field Myopia

• Is a condition that usually occurs when flying above the clouds or in a haze layer that provides nothing specific to focus on outside the aircraft

• Eye relaxes

  • Focal distance is between 10-30 feet

  • This means looking without seeing

• Search out and focus on distant light sources

Night Vision

• Night Blind Spot

  • rods are 10,000 times more sensitive to light than the cones

  • Like central blind spot

    • Look off center

• Night Adaption

  • Adjustment of the human eye to a dark environment.

  • Cones adapt rapidly to changes in light intensities

  • The rods can take approximately 30 minutes to fully adapt to darkness

    • A bright light, can completely destroy night adaptation

• Night Vision Protection

  • Sunglasses

  • Oxygen supply

  • High intensity lighting

  • Flight deck Lighting

  • Airfield etiquette 

Vestibular System and visual illusions

Vestibular system

• The inner ear that senses the way we are balanced

• In both the left and right inner ear, three semicircular canals are positioned at approximate right angles to each other

  • Positioned to detect pitch, roll, and yaw

  • Each canal is filled with fluid and has a section full of fine hairs

• Acceleration of the inner ear in any direction causes the tiny hairs to deflect

• The vestibular nerve transmits the impulses from the utricle, saccule, and semicircular canals to the brain to interpret motion.

Illusions

1. Vestibular 

   1. The leans

      1. most common illusion during flight

      2. A sudden return to level flight

      3. gradual and prolonged turn

      4. Leveling the wings

      5. banking in the opposite direction.

   2. Coriolis

      1. When a pilot has been in a turn

      2. for the fluid in the ear canal to move at the same speed as the canal.

      3. A movement of the head in a different plane,

      4. such as looking at something like pen

      5. may  feel turning or accelerating on an entirely different axis

      6. cross-check

   3. Graveyard Spiral

      1. In a prolonged constant-rate turn

      2. The illusion of not turning.

      3. During the recovery to level flight 

      4. The sensation of turning in the opposite direction 

      5. Causing a return to its original turn

   4. Somatogravic Illusion

      1. A rapid acceleration,

      2. during takeoff, 

      3. stimulates the otolith organs in the same way as tilting the head backwards.

      4. Feels like nose up

      5. Vice versa

   5. Inversion Illusion

      1. An abrupt change from climb to straight-and-level flight can 

      2. stimulates the otolith organs 

      3. Feel like tumbling backwards

   6. Elevator Illusion

      1. An abrupt upward vertical acceleration

      2. Turbulence

      3. Stimulates the otolith organs

      4. Feel like being in a climb.

2. Visual

   1. False Horizon

      1. A sloping cloud formation,

      2.  An obscured horizon,

      3.  A dark scene spread with ground lights and stars,

      4. patterns of ground lights can provide 

      5. inaccurate visual information, 

      6. align the aircraft with wrong horizon.

   2. Autokinesis

      1. Flying in the dark,

      2. Stationary light may appear to move if it is stared at for a prolonged period of time

   3. Runway Width Illusion

      1. Narrower- Higher than usual- Leading to a Lower Approach 

      2. Wider- Lower than usual- Leading to a Higher Approach

   4. Runway and Terrain Slopes Illusion

      1. Upslope- Higher than usual- Leading to a Lower Approach

      2. Downslope- Lower than usual- Leading to a Higher Approach

1. Featureless Terrain Illusion

   1. Black hole

   2. Absence of surrounding ground features, as in an overwater approach over darkened areas or terrain made featureless

2. Water Refraction

   1. Rain on the windscreen 

   2. Create an illusion of being at a higher altitude due to the horizon appearing lower than it is. 

   3. pilot flying a lower approach.

3. Haze

   1. Pilot will tend to be lower on approach 

4. Fog

   1. Illusion of pitching up

5. Ground Lighting Illusions

   1. Lights from streets nearby

   2. Pilots might line up on incorrect runway

“See and avoid” concept

• FAR 91.113

  • Right of way

  • Go through FAR 91.113 with Student

• Vigilant Lookout

  • Keep looking for Objects/ Aircrafts

• Preflight Planning

  • View NOTAMs, weather, or anything that my limit seeing other aircrafts

Proper visual scanning procedure

1. Periodically scanning the entire visual field outside of their aircraft to ensure detection of conflicting traffic.

2. average person has a reaction time of 12.5 seconds

   1. people tend to focus 10 - 30 feet in front of them

3. Continue to look outside

4. regularly spaced eye movements, should not exceed 10 degrees

5. Horizontal back-and-forth eye movements

Importance of knowing aircraft blind spots

Similar to driving a car

• Pilots are reminded of the requirement to move one’s head

• To search around the physical obstructions

• Door and window posts. The doorpost can cover a considerable amount of sky, 

• Small head movement may uncover an area which might be concealing a threat.

Proper clearing procedures

1. Prior to taxiing onto a runway or landing area for takeoff, scan the approach areas for possible landing traffic by maneuvering the aircraft to provide a clear view of such areas. It is important that this be accomplished even though a taxi or takeoff clearance has been received. 

2. During climbs and descents in flight conditions which permit visual detection of other traffic, execute gentle banks left and right at a frequency which permits continuous visual scanning of the airspace about them. 

3. Execute appropriate clearing procedures before all turns, abnormal maneuvers, or acrobatics.

   1. Two 90° turns in opposite directions before executing any training maneuver or two 90° turns in the same direction

Relationship between aircraft speed differential and collision risk

Fast versus slow

1. Faster you are traveling the harder it is to avoid a collision

   1. Maintain scan

Situations that involve the greatest collision risk

1. Traffic patterns

   1. Entering traffic pattern unaware of current traffic

2. Approach to a busier airport

3. Practice areas

4. Clear cloudless beautiful days

   1. “It’s a great flying day today”

5. Common departure and arrival times at international airports

6. VFR traffic not talking with Air Traffic Control, or on an airport frequency

Conclusion

• 5 Senses

• Vestibular system

• Vision in flight

• Illusions a pilot may encounter

• Scanning techniques/ collision avoidance

(Questions to assess student)

What are the 5 senses?

What does the vestibular system provide us?

Why are our eyes so important?

What are some illusions we may encounter any, how?

HW: 

Go over the types of illusions