FP-C #5 Flashcards
What range of gravitational force will cause unconsciousness?
6 to 8g
Define: physiologic altitude
The altitude perceived by the body
The stage of hypoxia experienced at 15 to 20,000 feet
Disturbance stage
FAR Part 135.89
Governs the use of supplemental oxygen by pilots and provides rules for pressurized and non-pressurized aircraft
List the two types of altitude
Physical altitude, physiologic altitude
The greenhouse effect can raise temperatures in the cabin of a helicopter by this much
50°F- 59°F
Describe: type II spatial disorientation
Occurs when a pilot does not sense spatial disorientation, but does sense a problem
Oxygen saturation range: critical stage of hypoxia
Less than 65%
Vibrations could cause significant affect the body between this range
1- 12 Hz
When flying at night, these colors of light are approved inside the cockpit
Red light and green lights
Define: physical altitude
Feet above the ground
Pressure changes and a cold can lead to these symptoms
Severe headaches, vertigo, nausea
The rate of improvement following oxygen support in altitude - induced hypoxia
Within minutes 100% oxygen
Describe: type I spatial disorientation
This occurs when the pilot does not notice that spatial disorientation exists and doesn’t sense a problem
The amount of time that judgment and coordination deteriorate to the point of inadequate or inappropriate function in the critical stage of hypoxia
3 to 5 minutes
The relationship between loudness and duration
Inversely - The louder the sound, the less time before damage occurs
Exposure to fuel vapors can result in these symptoms
Headaches, nausea
The four primary forces that act on an aircraft in flight
Lift, thrust, weight (gravity), drag
Effects of flicker vertigo
Nausea, vomiting, seizure, fainting
Criteria for non-pressurized aircraft to use oxygen continuously
If longer than 30 minutes at 10 to 12,000
General alcohol policy with respect to your shift
12 hours bottle to throttle
Low-frequency vibration can cause the following:
Body discomfort, chest pain, decreased vision, fatigue
Function of differential control method
Military applications mostly, lightweight
Over the counter medications and the FAA
The FAA has an approved list of prescription and over-the-counter medications that flight crew members are allowed to use
The cognitive manifestations during the disturbance stage hypoxia
Crew members not realizing they are affected
This is the most physiologic problem encountered in the flight environment for flight crew
Fatigue
What effect does a negative gravitational force cause?
Pushes blood toward the brain
The senses affected at the disturbance stage of hypoxia
Vision, hearing, sense of touch
Humidity’s relationship to temperature
Proportional humidity increases in temperature when temperature increases
The effects of rapid cabin depressurization
Hypoxia, decompression sickness, gastrointestinal expansion, hypothermia, dense fog within cabin
These are the three key components to maintain spatial orientation
Effective perception, integration, interpretation of visual/vestibular, proprioceptive sensory information
Describe: type III spatial disorientation
Occurs when a pilot is affected by illusion of intense movement and is unable to reorient
How many types of spatial disorientation are there?
3
At 15,000 feet, what is barometric pressure?
429
The keys to recognition and treatment of altitude hypoxia
Avoid hypoxia is key to safety
This is how you minimize the effects of vibration
Don’t lean against the airframe, padded seats, use of shoulder and lap belts appropriately
Define: spatial disorientation
Condition in which a person has an incorrect understanding of the body’s position with respect to the earth
Causes: fatigue
Lack of sleep, jetlagged, constant vibration, 24-hour operations
Define: Dysbarism
A syndrome resulting from the difference between barometric pressure and pressure of gases inside the body
Temperature declines with altitude by this rate
3°F- 5°F/ 1000 feet
Functional goals of isobaric control systems
Maintain cabin pressure 5-8000 feet, to avoid requiring oxygen for passengers
Psychomotor manifestations during the disturbance stage of hypoxia
Decreased muscular coordination: difficult speech, illegible handwriting, worsening dexterity
These are the hallmark signs of impairment in the disturbance stage of hypoxia
Stammering and illegible handwriting
The altitude where one would experience the critical stage of hypoxia while on 100% oxygen
44,800 feet and above
The effects of slow cabin pressurization
Hypoxia over time - leads to undetectable
All pilots must wear oxygen above this level
35,000 feet
The number of annual rapid decompressions
40 to 50 - most occur above 30,000
Crewmembers should avoid using this color light when flying at night to prevent pilot’s vision loss
White light
Mnemonic for a person’s tolerance to stressors of flight
IM SAFE
The effects of long exposure to noise
Damage, or completely destroy, soft tissue of the inner ear
Define: third spacing
The loss of fluids from the intravascular space into the tissue
A dangerous respiratory concern with altitude hypoxia
Hyperventilation
Alcohol consumption and altitude
1 ounce equals 2000 feet physiologic altitude - two beers equal 4-8000 feet physiologic altitude
Pathophys: hyperventilation syndrome
bicarb and CO2 decrease in blood–> vasoconstriction of cerebral arteries–> hypoxia–> unconsciousness–> cellular acidosis–> death
This is the most effective method of protecting people from the physiologic effects of reduced barometric pressure
Cabin pressurization
The greatest pressure change takes place between these altitudes
Sea level and 5000 feet
Define: bariotitis media
Condition resulting from the failure of the middle ear space to equalize pressures when going from low to high atmospheric pressure
___ opposes gravity, ___ opposes drag
Lift, thrust
Disadvantages of differential control method
Supplemental oxygen and pressure suits required at high altitudes
Two types of pressurizing systems in aviation
Isobaric control system, differential control method
Flicker vertigo can be caused by flickering at this range
4 to 20 cycles/second
Two major consequences to fatigue
Delayed reaction time, increased vulnerability for error
Alcohol and histotoxic hypoxia
Alcohol can inhibit the available oxygen for hemoglobin and delay metabolism at the cellular level
Explain the Mnemonic “IM SAFE”
Illness, medication, stress, alcohol, fatigue, emotion
Disadvantages of an isobaric control system
Requires heavy fuselage and airframe, adds weight to the aircraft, has explosive rate of decompression that can occur
What effect does positive gravitational force cause?
Pushes blood away from brain
Serious consequences of hyperventilating at altitude
Rapid decrease of sodium bicarbonate in the blood causing elevation in blood pH (respiratory alkalosis)
Define: flicker vertigo
An imbalance in brain cell activity caused by exposure to low-frequency flickering or flashing of a bright light
The stage of hypoxia experienced at 20,000 feet or above
Critical stage
The stressors of flight
Low oxygen, barometric pressure changes, verbal changes, vibration, decreased humidity, noise, fatigue, gravitational forces, spatial disorientation, third spacing, flicker vertigo, fuel vapors, weather, anxiety, night flights
