# Presentation: 440966

## Charles V. Nolan    Manager

**TAMPA, FLORIDA**
**Flight Standards District Office**
**(813) 639-1540**
**HOURS: 8:00 - 4:30 Weekdays**
**(except Federal holidays)**
**Charles V. Nolan    Manager**

## SPATIALDISORIENTATION

**Buz Massengale**
***Safety Program Manager***
***Tampa, FL FSDO***

**Notes:**
RUN VIDEO: “THE BUSINESS TRIP”
DISCUSS WHAT HAPPENED
TONIGHT’S PROGRAM ON SPATIAL DISORIENTATION HAS TO BEGIN WITH SPATIAL ORIENTATION - WHERE WE ARE
POSITION IN SPACE, ON A MAP
SOME PEOPLE NEVER SEEM TO KNOW WHERE THEY ARE, AND WE ALL KNOW THE ONES WHO DON’T WANT TO ASK FOR DIRECTIONS
OBJECTIVES TONIGHT:
1. HOW WE ORIENT OURSELVES IN SPACE
2. HOW WE BECOME DISORIENTED
3. DEMONSTRATION OF ILLUSIONS AND SOME TYPES OF DISORIENTATION
10% OF FATAL ACCIDENTS (15 - 16% 1970 - 1975, DOWN TO ABOUT 7% BY 1992)
15% OF FATAL MILITARY ACCIDENTS
LET’S BEGIN WITH HOW WE SENSE OUR POSITION

## THREE SENSORY SYSTEMS

**VISION**
**VESTIBULAR SYSTEM**
**SOMATOSENSORY SYSTEM**

**Notes:**
WE USE 3 SENSORY SYSTEMS FOR ORIENTATION

1.  90% INPUT FROM VISION

2.  VESTIBULAR SYSTEM
    -INNER EAR
    Semicircular Canals
    Otolith organs

3.  SOMATOSENSORY SYSTEM 
“SEAT OF THE PANTS”
OTHER SENSES

## LEARNING TO FLY

**USE BASIC ORIENTATION**
**USE ALL AVAILABLE SENSES**
**OUTSIDE REFERENCES**
**INSTRUMENT REFERENCES**

**Notes:**
1.  STUDENTS TAUGHT USING VERY BASIC ORIENTATION
2.  USE ALL AVAILABLE SENSES
    Sight: aircraft attitude, height above ground, geographic orientation
    Hearing: engine power setting, airspeed
    Touch: aircraft attitude, aircraft vibrations, G-forces
    Smell: normal/emergency conditions
    Taste: not really used, except in our choice of co-pilotsor watering holes
3.  BEGIN WITH OUTSIDE REFERENCES
4.  INTEGRATE OUTSIDE REFERENCE TO INSTRUMENT INDICATIONS
DONE ALMOST ENTIRELY WITH VISION

## VISION

**90% of orientation**
**Most reliable sense**
**Instrument/visual flight elements**
**SCAN!!!**
**Interpretation**
**Aircraft control**
**Even reliable vision can be fooled**
**“****Optical illusions”**

**Notes:**
1.  90% of our orientation comes from our eyes alone
2.  Most reliable sense - can’t fly w/o it... there are NO blind pilots, no Braille instruments
3.  Successful aircraft flight consists of learning 3 elements
a.  SCAN - Eye movement to see everything outside/inside that’s necessary
    Orderly, disciplined movement of eyes
    Avoid unnecessary scanning, no fixation
    Takes practice - “push-ups” for the eyes
b.  INTERPRETATION - Understanding what you see after the scanning
    Takes training and practice
    Failure can be deadly - AA Cali, Colombia accident
c.  AIRCRAFT CONTROL - Basic hand/eye/foot coordination
4.  EVEN RELIABLE VISION CAN BE FOOLED
5.  OPTICAL ILLUSIONS

## CAN YOU READ THIS?

**Notes:**
LOOK FOR THE WORD “THE” TWICE

## WHICH LINE IS LONGER?

**Notes:**
BOTH LINES ARE THE SAME LENGTH

## DO YOU SEE THE GRAY?

**Notes:**
THE INTERSECTIONS OF WHITE LINES GIVE THE APPEARANCE OF BEING GRAY

## WHAT DO YOU SEE?

**Notes:**
A PERSON’S FACE, OR THE WORD “LIAR”

## WHAT DO YOU SEE?

**Notes:**
IS IT A GOBLET OR A PAIR OF FACES LOOKING AT EACH OTHER?

## HOW OLD IS SHE?

**Notes:**
DO YOU SEE AN OLD LADY OR YOUNG WOMAN?

## THE DANCING ELEPHANT

**Notes:**
HOW MANY LEGS?

## AVIATION-RELATEDVISUAL ILLUSIONS

**Featureless terrain**
**False horizons**
**Ground lighting**
**Autokinesis**
**Runway width illusion**
**Runway slope illusion**

**Notes:**
1.  An absence of surrounding ground features, as when approaching over water, darkened areas, or wide expanses of snow.  Illusion of being higher than actually.  Pilots tend to fly a lower approach, may land short.  Factor in JFK?
2.  Sloping cloud formation, obscured horizon, lines of ground lights can give inaccurate picture of actual horizon
3.  Merging ground lights and stars, confusing ground light arrays, such as might incorrectly indicate a runway.  Brighter than normal runway/approach lights can  create illusion that runway is closer
4.  In the dark, a single point of light will appear to move and provides no cues for determining altitude.  A real danger among pilots attempting to circle around a lone point of light in helicopters
5.  Wider than usual runway creates illusion that the aircraft is lower than normal, causing pilot to fly a higher approach.  Very narrow runway can cause pilot to fly a lower approach.
6.  Upsloping runway creates illusion that runway is shorter and that the aircraft is high, causing pilot to make lower approach.  Downsloping runway causes pilot to fly a higher approach.

## AVIATION-RELATEDVISUAL ILLUSIONS

**Terrain elevation**
**Atmospheric illusions**
**Rotorwash drift (helicopters)**
**Waterfall (helicopters)**
**Brown/Whiteout (helicopters)**

**Notes:**
1.  Traffic patterns that overfly terrain which is significantly higher than airport elevation gives the illusion that the pilot is lower than normal, and causes the pilot to fly a higher pattern and approach.  Hilltop runways surrounded by lower terrain give the illusion that the pilot is too high, so the pilot will tend to fly a tighter pattern and lower approach.
2.  Rain on windscreen can create illusion of being at higher altitude; haze creates illusion of being at a greater distance. Movement in and out of clouds creates the illusion of greater speed.  Fog penetration can create a pitch-up illusion.
3.  Helicopter pilots who hover over water or expanses of grass get the illusion of a drift opposite the direction of the rotorwash ripples.
4.  Rotor downwash accelerates rain and snow downward, giving the false illusion that a hovering helicopter is in a climb.
5.  Helicopters approaching to land in loose snow or dust can create a sudden brown or whiteout condition

## VESTIBULAR APPARATUS

**Second method of position determination**
**Supports vision**
**Very strong in absence of vision**
**Detect angular accelerations (turns)**
**Detect linear acceleration & gravity**
**Two systems, located in middle ear**

**Notes:**
1.  OUR SECOND METHOD OF POSITION DETERMINATION
2.  SUPPORTS VISION
3.  CAN SUBSTITUTE FOR VISION: BLIND PEOPLE
    -WALKING IN DARK (BALANCE ON ONE FOOT W/EYES CLOSED
    -WORKS FINE ON DECK - NOT IN AIR
    -WORKS FINE WHEN HEALTHY
    -MESSED UP WHEN SICK, DRUNK: DIZZINESS, NAUSEA
4.  DETECT ANGULAR ACCELERATION: 2 DEG./SEC THRESHOLD
5.  DETECT LINEAR ACCELERATION AND GRAVITY (STATIC POS.)
6.  TWO INDEPENDENT SYSTEMS, ONE IN EACH MIDDLE EAR, CAN FUNCTION WITH ONLY ONE.

## SEMICIRCULAR CANALS

**Notes:**
ROLL/PITCH/YAW SENSATIONS THROUGH SEMICIRCULAR CANALS
DETECT ROLL/PITCH/YAW THROUGH FLUID-FILLED SEMICIRCULAR CANALS

## OTOLITH ORGANS

**Notes:**
DETECT GRAVITY AND LINEAR ACCELERATION
STATIC POSITION DETERMINATION RELATIVE TO FORCE OF GRAVITY
    “WHAT’S UP?”
SMALL BONE-LIKE WEIGHT RESTING ATOP NERVE FIBERS
MOVES RELATIVE TO BODY TILT OR LINEAR ACCELERATION

## SOMATOSENSORY SYSTEM

**“****Seat of the Pants”**
**Aids vision and vestibular systems**
**Tactile pressure receptors**
**Binaural hearing**

**Notes:**
1.  Classic “Seat of the Pants” sensations
2.  Aids visual and vestibular systems.  A secondary means of determining position
3.  Nerves in skin, muscles, joints that sense pressure, pressure differentials; heat, cold.  Can tell whether you’re sitting on a hot tin roof or are up to your ass in alligators.
4.  Binaural hearing gives indication of your position relative to a sound source

## TAKEABREAK

**Notes:**
SUNCOAST 99’S ARE PROVIDING REFRESHMENTS AND ARE ASKING FOR A NOMINAL DONATION TO HELP PROVIDE A SPACE CAMP SCHOLARSHIP AND AVIATION TRAINING SCHOLARSHIPS TO DESERVING YOUNG PERSONS.

TIME NOW IS: 

BE BACK IN SEATS IN 10 MINUTES

## Slide 20

**Notes:**
NOW THAT  WE’VE DISCUSSED SPATIAL ORIENTATION
WE CAN NOW DISCUSS DIS-ORIENTATION

## SPATIAL DISORIENTATION

**Humans not flight adapted**
**Vestibular/somatosensory backs up vision**
**Disorientation**
**Inability to determine position**
**Confusion about position**

**Notes:**
1.  HUMANS AREN’T BIRDS... EARTH-BOUND CREATURES.  
    POSITION SENSING IS BASED ON BEING ON DECK
2.  VESTIBULAR SYSTEM CAN TAKE OVER FROM VISION, AS LONG AS WE STAY ON DECK... 
    CANNOT WORK IN FLIGHT... 
    178 SECONDS... PILOTS NEED VISION... 
    VESTIBULAR/SOMATOSENSORY POSITION SENSATION CAN
    BACK UP VISION, BUT NOT THE OTHER WAY AROUND
3.  a.  WHEN WE CAN NOT ACCURATELY DETERMINE OUR POSITION, WE BECOME DISORIENTED.  
     b.  SAME IS TRUE WHEN WE BECOME CONFUSED ABOUT OUR POSITION.

## FOOLING OUR SENSES

**Sickness**
**Drunk**
**Unfamiliar environment**
**Simulators**

**Notes:**
1.  VESTIBULAR/SOMATOSENSORY SYSTEMS PRONE TO BEING MESSED UP IN MANY WAYS
    SICKNESS - TRY GETTING OUT OF BED!
    DIZZINESS, NAUSEA SYMPTOMS- WHEN WE’RE DIZZY, OR SERIOUSLY DISORIENTED, THERE’S A PROFOUND EFFECT ON THE EYES (NYSTAGMUS) - MAKES IT DIFFICULT TO FOCUS!
2.  DRUNK: THE ONLY WAY DRUNKS FUNCTION IS WHEN THEIR EYES ARE OPEN, BUT THEIR BALANCE IS DEFINITELY IMPAIRED.
3.  UNFAMILIAR ENVIRONMENT CAN CREATE SENSORY ILLUSION
    CARNIVAL RIDES
    AEROBATICS
    EXTREME ACCELERATIONS OR POSITIONS
    DENIED VISUAL CUES (VMC to IMC, GYRO FAILURE)
4.  SIMULATORS: DESIGNED TO FOOL THE SENSES!

## SENSORY ILLUSIONS

**Sub-threshold acceleration**
**Straight & Level**
**The “Leans”**
**Coriolis Illusion**
**Somatogravic Illusion**
**Elevator Illusion**

**Notes:**
1.  Less than 2 deg./sec. acceleration (bank rate) is not detectable.  No stimulation of fluid in semicircular canals.  Pilot feels like S & L.  The deviation only becomes noticeable when gravity/centrifugal forces alert the pilot to different attitude, or heading has wandered
2.  Detectable acceleration in turn, then equilibrium (constant-rate turn)... fluid ceases to move in semicircular canals...pilot senses S & L
3.  The “Leans” - Fluid which had been stationary due to constant rate turn now moves in opposite direction when righting the aircraft from a bank.  Pilot senses a turn in the opposite direction.  Tendency to want to return the aircraft to a bank to make it “feel” right.  Can lead to
      “Graveyard Spiral” - Pilot succumbs to feeling of leans and returns aircraft to a bank, only steeper... as bank steepens, nose drops, when pilot attempts to recover by pulling back on yoke, the turn tightens.
4.  Coriolis Illusion - Head movement made while in turn can set fluid in motion in more than one semicircular canal, creating illusion of climbing/descending while turning.  Can be very intense, sensation of tumbling out of control.
5.  Somatogravic illusion - Rapid acceleration stimulates otoliths backward, as if a pilot is leaning backward... gives false illusion of nose-up pitch.  Sudden deceleration has opposite effect.  A problem among Naval aviators during catapult launches
6.  Abrupt upward vertical acceleration (updraft) can stimulate otoliths to falsely indicate climb sensation.  Downdraft creates opposite effect.

## Slide 24

**Notes:**
WHAT’S ONE OF THE BEST, MOST ACCEPTABLE WAYS WE INDUCE AN UNRECOGNIZED SPATIAL DISORIENTATION?
SIMULATORS!!!
    a. DENY VISION TO THE OUTSIDE, BUT KEEP IT INSIDE THE BOX
    b. PROVIDE FALSE VISUAL CUES INSIDE THE BOX
    c. INDUCE LINEAR/ANGULAR ACCELERATIONS TO THE BODY
WATCH FROM THE OUTSIDE HOW A FULL MOTION SIMULATOR ACTUALLY MOVES

WE DON’T HAVE A FULL-MOTION SIMULATOR HERE, BUT WE DO HAVE THE NEXT BEST THING
WE CAN SIMULATE SOME OF THE ILLUSIONS WE’VE DISCUSSED, BUT NOT ALL... ONLY THOSE DEALING WITH ANGULAR ACCELERATIONS.
A BETTER SIMULATION CAN BE FOUND BY USE OF THE VERTIGON AT MAJOR AVIATION EVENTS, SUCH AS SUN-N-FUN OR AIR VENTURE (OSHKOSH)

## SURVIVINGSPATIAL DISORIENTATION

**RELY ON *****VISION***
_**PRACTICE**_** INSTRUMENT FLIGHT**
**OUTSIDE REFERENCE IF POSSIBLE**
**INSTRUMENTS IF NECESSARY**
**SCAN**
**INTERPRET**
**CONTROL**

**Notes:**
1. REGARDLESS OF HOW YOUR VESTIBULAR SYSTEM/SOMATOSENSORY SYSTEMS ARE FOOLED, THE KEY TO SURVIVAL IS TO RELY ON YOUR EYES!!!
2. PRACTICE INSTRUMENT FLIGHT, INCLUDING UNUSUAL ATTITUDE RECOVERIES AND PARTIAL PANEL SKILLS
  - WINGS PROGRAM
  - HOW ABOUT A BACKUP VACUUM SOURCE OR ELECTRICAL GYROS?
2.  GET TO VFR, STAY THERE
3.  USE INSTRUMENTS IF YOU HAVE TO
    REMEMBER 3 ELEMENTS: (a) SCAN, (b) INTERPRET, (c) CONTROL

## ?

**QUESTIONS?**

## Thanks for coming...

**Fly Safely**
**Drive Safely**

**Notes:**
WHEREVER YOU’RE GOING, FLY SAFELY AND DRIVE SAFELY
COME BACK TO THE NEXT SAFETY MEETING, BRING SOMEONE WHO NEEDS TO HEAR THE WORD OF SAFETY.  LET’S FILL THE EMPTY SEATS!

## WWW.FAA.GOV/FSDO/TPA

**WWW.FAA.GOV/FSDO/TPA**