What are your 6 hr. restrictions?
centrifuge runs and no residual effects
What are your 12 hr. restrictions?
- Alchohol(+ no residual effects)
- Altitude chamber
- Simulator sickness (time starts after symptoms are gone)
- Local anesthesia (to include dental)
What are your 24 hr. restrictions?
- SCUBA diving
- Hypobaric (altitude chamber if >25k ft)
- Plasma donation
What are your 48 hr. restrictions?
General, Spinal, or Epideral anesthesia
What are your 72 hr. restrictions?
Blood donation (> 200cc) max twice per year
What are your CS/Tear gas restrictions?
no restrictions if residual effects have been resolved. Contaminated clothing or ALSE must be exchanged or decontaminated
What is the definition of Hypoxia?
a condition that results from having an insufficient amount of oxygen in the body
What are the different types of Hypoxia?
occurs when there is not enough oxygen in the air. Caused by high altitude
a reduction in the oxygen carrying capacity of the blood. Causes - blood loss or carbon monoxide
innadequate circulation of the blood. Causes - heart failure or high G maneuvers
occurs when there is an interference with the us of oxygen by body tissue. Causes - alchohol and drugs
Stages of Hypoxia?
(SL - 10k ft.) - mild hypoxia. Symptoms - night vision deteriorates at about 4k ft.
- Compensatory (10k - 15k ft.) - pulse rate, blood pressure, circulation rate, and cardiac output increases. Symptoms - impaired efficiency, drowsiness, poor judgement.
- Disturbance (15k - 20k ft.) - physiological responses can no longer compensate for oxygen defficiency. Symptoms - impaired vision/ flight control/ handwriting/ coordination/ speech/ and memory, happy/mean drunk, hearing one of last senses to go.
- Critical (>20k ft.) - happens within 3-5 min. Symptoms - loss of conciousness, convulsions, and then death.
Prevention of Hypoxic Hypoxia
- limit time at altitude
- use supplemental oxygen during night flights above 4k ft.
- pressurized cabin
Treatment of Hypoxia
- give 100% oxygen if possible
- descend below 10k ft.
Self impossed stresses
- no self medicating, affect people differently, unwanted effects
- Exhaustion - lack of rest/sleep/physical exercise
- Alchohol - each ounce consumed raises physiological altitude by 2k ft.
- Tobbaco - CO2 has a 200-300 time greater affinity for red blood cells then O2. Causes Hypemic Hypoxia. Smokers physiological alt at SL is 5k ft.
- Hypoglycemia - low blood sugar. Use proper nutrition.
Considerations if using drugs
- Allergic reactions
- Predictable side effects
- Synergistic effects
Middle ear discomfort
- mainly experienced during a descent caused by trapped air expanding and contracting in the middle ear
- Preventionswallow or yawn
- Valsalva - close mouth, pinch nose, and blow(never valsalva while ascending)
- if not remedied, descend very slowly
- of not solved on ground, see flight surgeon
Spatial Disorientation def
an individuals innaccurate perception of position, attitude and motion relative to the surface of the earth (or significant objects; e.g. trees, buildings). The result causes the pilot not to believe his flight instruments. The pilot mistakenly believes his false senses.
a false perception of reality. Occurs when various sensory inputs that affect the brain disagree with each other
dizzy or spinning sensation
Types of SD
- Type 1 - Unrecognizedmost dangerous type
- aviator doesn't think anything is wrong
- usually results in fatal crash
- Type 2 - Recognizedpilot realizes something is wrong
- pilot does not understand he is having SD
- Type 3 - Incapacitatingpilot has overwhelming sensation of movement and cannot control the aircraft
3 types of sensory systems
- most important sensory system
- eye provides 80% of orientation info.
Fire, Fire, Fire CRASH CSAR
- Flicker vertigo
- Relative motion
- Height perception
- Altered planes of reference
- Reversable perspective
Vestibular system (inner ear consists of:)
- Otolith organs: small sensory hairs that respond to gravity and linear acceleration
- Semicircular canals: sense changes in angular acceleration. Will react to roll, pitch, or yaw attitude
- Somatogyral - caused by angular accelerative and decelerative flight
- Somatogravic - caused by changes in linear accelerations and decelerations or gravity that stimulate the otolith organs
- Graveyard spin
- Coriolis illusion
- most common form of SD
- pilot fails to recognize angular motioni during percieved straight and level flight
- pilot quickly reacts once roll is noticed and this gives a sensation of rolling in the opposite way
- AI shows a level attitude yet pilot feels as if he is still rolling
- causes pilot to lean into the direction of the original roll
- pilot unknowingly enters a descending turn which falsely stimulates the semicircular canals
- once recognized, the PI corrects to straight and level flight, put the PI will percieve the aircraft is turning in the opposite direction
- the Pi will correct for this false perception and reenter the original spin with increased rates of descent
- PI enters a prolonged turn where the stimulated semicircular canal becomes equalized
- PI makes a head motion on a different geometric plane other than that of the turn
- the yaw axis semicircular canal is moved to another plane of rotation resulting in a sensation of a turn in the opposite direction and the fluid then stimulates the other two canals
- the result is a perception of motion which creates a very strong tumbling sensation
- When aircraft accels and decels, inertia causes the otolith organ to sense a noses high or low condition
- the PI falsely corrects this perception by pulling aft (or forward) cyclic
- occurs during upward acceleration
- the eyes will track downward
- the pilot senses the aircraft nose is going up
- the pilot falsely corrects this perception by applying forward cyclic
- opposite of elevator illusion. Occurs during downward movement of aircraft
- the eyes will track upward
- the PI senses the aircraft nose is going down
- the PI falsely corrects this perception by applying aft cyclic
- may occur when entering autorotation
- another name is "seat of the pants" flying
- this system of orientation is the result of pressure on joints, muscles, or skin
- illusion may occur if the PI feels pressure on his body and misenterprets it for a climb/descent/ or turn
- rarley occur
Never Never Avoid Trust
Never fly without visual reference points (horizon or AI)
- Never try to fly VMC and IMC at the same time
- Avoid fatigue, smoking, hypoglycemia, hypoxia, and anxiety which will aggrevate the illusion
- Trust you instruments
Treatment of SD
Develop a good cross check; refer to instruments
- Delay intuitive actions
- Transfer controls
state of feeling tired, weary, or sleepy that results from prolonged mental or physical work, extended periods of anxiety, exposure to harsh environments, or loss of sleep. Boring tasks may increase fatigue.
Types of Fatigue
- Accute - fatigue experienced between 2 regular sleep periods.
- Chronic - occurs over a long period of time and may be the result of inadequate recovery of successive periods of accut fatigue
- Burnout (motivational exhaustion) - after a period of prolonged chronic fatigue, the person shuts down and ceases to function occupationally and socially. A complete lack of motivation.
What are the considerations for Distance Estimation and Depth Perception?
- Monocular cues (GRAM)
- Geometric Perspective (LAV)
- Linear perspective
- Apparent Foreshortening
- Vertical position in the field
- Retinal Image Size (KITO)
- Known size of objects
- Increasing/decreasing size of objects
- Terrestrial Association
- Overlapping Contours or Interposition of Objects
- Aerial perspective (FLP)
- Fading of colors or shades
- Loss of detail or texture
- Position of light source and direction of shadow
- Motion Parallax
What are the 3 types of vision?
- Photopic occurs in daylight and bright light
- produces sharp images and color vision
- requires use of central vision
- involves cones only
- Mesopic occurs at dawn, dusk, and in full moonlight
- reduces color vision and visual accuity
- involves both rods and cones
- Scotopic occurs on dimly lit nights
- decreases visual accuity
- causes loss of color interpretation
- causes night blind spot
- requires use of peripheral vision and recognition of object silhouettes
- involves rods only
Night vision techniques
- Off-Center Vision - look 10 degrees off object in any direction and no longer than 2-3 seconds for any technique
- Scanning - Right to left or left to right or stop-turn-stop-turn patterns
- Shapes or silhouttes - used to identify structures such as churches, mosques, or barn silos