Flight Physiology [Block 5] Flashcards
What is the most important organ for pilots?
Eyes
Cones
What are they?
What information do they provide the eye?
When is it best in use?
Where is it located and does it read color?
–Receptors concentrated in focal area
–Detail & Color Oriented
–Best in Light
–Cones – Color – Center of eye
Rods
What are they?
What information do they provide the eye?
When is it best in use?
Where is it located and does it read color?
–Receptors along periphery
–Not sensitive to color
–Detects movement and shapes
–Good for low light levels
Night Vision
•In low light, the cones will not perceive light
•Night Blind Spot
–Occurs in focal center where a large concentration of cones are located
–Looking 4-12 degrees to the side of object best way to see
How to avoid optical illusions? (8)
•How to Avoid –Awareness of possible illusions –Use instruments to verify perceptions –Use autopilot –Anticipate Illusions –Use Visual Glideslope Indicators (VASA, PAPI, etc) –Minimize Distractions –Maintain proficiency –Adjust lighting aids as necessary
Anatomy of the inner ear. (5)
More Info…
- Semicircular Canals
- Canals are filled with fluid
- Force move fluid
- Fluid stimulates hairs in canal
- Translates into movement in brain
- Canals insensitive to gradual changes of direction.
- Motion greater than 3 degrees per second is necessary to sense turning
Vestibular Illusions (6)
- Leans
- Coriolis Illusion
- Graveyard Spin / Graveyard Spiral
- Somatogravic Illusion
- Inversion Illusion
- Elevator Illusion
Leans
What is it?
How does a pilot correct this?
- An abrupt correction from a bank that was entered too slowly to stimulate the motion sensing system creates the illusion of banking in the other direction.
- Pilot corrects by re-entering the banked attitude.
Coriolis Illusion
•An abrupt head movement in a prolonged constant rate turn that has ceased stimulating the motion sensing system can create the illusion of rotation or movement in an entirely different axis.
Graveyard Spin
Spin: A proper recovery from a spin that has ceased stimulating the motion sensing system can create the illusion of entering a spin in the other direction.
–Pilot re-enters original spin.
Graveyard Spiral:
Spiral: An observed loss of altitude during a coordinated constant rate turn that has ceased stimulating the motion sensing system can create the illusion of being in a descent with the wings level.
–Pilot pulls back on control yolk, causing the aircraft to descend at a faster rate.
Somatogravic Illusion
•A rapid acceleration during takeoff can create the illusion of being in a nose high attitude.
–The disoriented pilot may push the aircraft into a nose-low or dive attitude.
•Rapid deceleration can have the opposite effect
Inversion Illusion
•An abrupt change from climb to straight and level can create the illusion of tumbling backwards.
–Pilot may then push the aircraft into a nose-low attitude, further intensifying the illusion.
Elevator Illusion
- An abrupt upward vertical acceleration, usually by an updraft, can create the illusion of being in a climb.
- An abrupt downward vertical acceleration has the opposite effect.
Factors Effecting Illusions (6)
•Changes in acceleration & deceleration
–Forward acceleration causes a sensation of nose-up pitch
- Cloud Layers
- Low level flight over water
- Repeated transitions between VMC and IMC
- Unperceived changes in flight attitude
- No horizon/low visibility
Illusion Avoidance (7)
- Anticipate illusion situations
- Be able to recognize false sensations
- Develop instrument interpretation skills
- Be decisive about transitioning to instruments
- Avoid flying under stress
- Even experienced pilots encounter brand new illusions
- Stay ahead of the airplane
Atmospheric Considerations test question
•Composition
–78% nitrogen, 21% oxygen at all altitudes
1% other
•Pressure decreases as altitude increases.
–However, the air composition remains unchanged
Physiological Zones
•Physiological Zone - SL to 10,000’
–We can adapt in this zone
•Physiological Deficient Zone - 10,000’ to 50,000’
–Majority of commercial flying
–Hypoxia due to altitude, as well as trapped and evolved gas problems, are concerns
Hypoxia Definition
•Lack of sufficient oxygen in the body to the point where function is impaired.
–Is due to a number of causes
–Can occur at any altitude
•Clearly is a pilot’s most important physiological concern.
Hypoxia Effects:
Influenced by?
•Significantly affects performance…can lead to incapacitation and death! •Influenced by multiple factors –Atmospheric considerations –Respiration problems –Blood donation –Oxygen equipment design … to name a few.
Four Types of Hypoxia Test Question
- Hypoxic
- Hypemic
- Stagnant
- Histotoxic
Hypoxic Hypoxia
What causes this?
How is it corrected?
•Partial pressure of oxygen is insufficient
–You cannot absorb adequate oxygen
•Correction: breathe a greater percentage of oxygen or oxygen under pressure
–Oxygen systems vary in what they deliver
–Descend to higher barometric pressures
Hypemic Hypoxia
What is the causes and effects?
•The oxygen-carrying capacity of the blood is reduced
–Carbon Monoxide interferes with oxygen binding to the blood
•Smoking, engine exhaust
–Sulfa drugs can have an effect also
–Blood donation also limits capability
Blood Donation
What is the effect of donation?
How long must you wait after blood transfusion?
How long must you wait after plasma donation?
•Symptoms of hypoxia at lower altitudes
•UND Policy
–72 hour wait after a blood donation or transfusion
–12 hour wait after a plasma donation
Stagnant Hypoxia
•Oxygen deficiency due to impaired circulation
–G forces from maneuvers
–Positive pressure breathing for extended periods
–Disease of the blood vessels