Hypoxia: A condition where not enough oxygen is being circulated in the bloodstream.
4 types of hypoxia:
- Hypoxic
- Hypemic
- Stagnant
- Histoxic
As altitude increases, the amount of available oxygen decreases. Hypoxia can be expected to occur at higher altitudes above 10,000 ft MSL and it can result in unconsciousness
Symptoms: headache, decreased reaction time, euphoria, visual impairment, drowsiness, lightheaded, dizzy, tingling in fingers and toes, numbness, cyanosis
Fly at lower altitudes or use supplemental oxygen
Hyperventilation: An excessive loss of carbon dioxide in the bloodstream due to prolonged heavy breathing (stress or fear).
Symptoms: pale, headache, decreased reaction time, euphoria, visual impairment, drowsiness, lightheaded, dizzy, tingling in fingers and toes, numbness
Reduce the breathing rate, breathe in a bag or talk out loud
Sinus Block: a pressure imbalance between the inner ear and ambient (outside) air
Symptoms: impaired hearing, pain (symptoms are exacerbated by head colds and sinus infections)
Avoid flying with upper respiratory or nasal allergic conditions. Chewing gum stretching mouth or pinch the nose shut while exhaling may alleviate the symptoms
Motion Sickness: cause: conflicting signals received by the brain regarding the positional state of the body in space.
Symptoms: paleness, sweating, general discomfort, dizziness, nausea and vomiting (symptoms are exacerbated by high air temperature, turbulence, and fear or anxiety).
Open fresh air vents, focus eyes outside the aircraft, avoid unnecessary head movements, and land if necessary.
Spatial Disorientation: Lack of orientation regarding the position attitude or movement of the aircraft in space. It is caused by conflicting information received by the brain from kinesthetic, visual and vestibular sources.
Spatial disorientation is most likely to occur in conditions of limited visibility
The best way to overcome the effects of spatial disorientation is to focus on and trust the aircraft instruments.
Vision: The area where the optic nerve attaches to the rear (retina) of the eyeball contains no visual receptor cells (rods and cones) This produces a blind spot in person’s field of vision.
The optimal way to scan for traffic is to bring small portions of the sky into the central field of vision, slowly and in succession.
- Prior to night flight, pilots should avoid bright white lights for at least 30 minutes.
- Off-center viewing is best for night vision.
Visual Illusions:
- Haze: causes objects or terrain to appear further away than they actually are.
- Autokinesis: (night) after staring at a point of light for more than a few seconds it appears to start moving on its own.
- False Horizon: (night) occurs when the natural horizon is obscured or not readily apparent. It can be generated by confusing brights stars and city lights.
- Sloping Runway: an upward sloping runway may give the illusion that the aircraft on approach is higher than actually is. A downward sloping runway may make it appear that the aircraft is lower.
Carbon Monoxide Poisoning: Carbon monoxide (CO) attaches itself to the red blood cells and prevents oxygen from being attached and transported. It takes about 48 hours to purge carbon monoxide from the bloodstream. Carbon monoxide poisoning can cause unconsciousness followed by death.
Carbon monoxide us a product of combustion can seep into the cockpit from the engine exhaust particularly via the heating system in some aircraft. Although CO is odorless, unusual smells in the cabin could indicate that it is present with other gases.
Symptoms: headache, blurred vision, dizziness, drowsiness, loss of muscle power (susceptibility in increased at higher altitudes since there is less availability of oxygen)
Open fresh air vents, turn off the heater, use supplemental oxygen
Scuba diving: it may cause nitrogen to dissolve into the body tissues and fluids. A quick reduction in atmospheric pressure may cause nitrogen bubbles to form into the body causing nerves pain and possible incapacitation.
The minimum recommended time between non-decompression diving and flight is 12 hours. The minimum time between decompression stop diving and flight is 24 hours.
Drugs: Pilot performance can be seriously degraded by both prescribed and over the counter medications as well by the conditions for which they are taken.
The FARs prohibit pilots from performing crew member duties while user any medication that affects the faculties in any way contrary to safety. Pilots should not fly as a crew member while taking any medication unless that medication is approved by the FAA.
Alcohol: A pilot with a blood alcohol level of more than 0.04 percent may not fly.
A pilot may not fly until 8 hours have passed since his last consumption of alcohol.