Human Factors Flashcards
What are the seven basic rules the National Heart Foundation suggest will lead to a healthy BMI?
- Reduce your fat intake. Most people eat far more fat than is necessary.
- Reduce your salt intake. Too much salt can lead to high blood pressure and heart problems
- Reduce your sugar intake.
- Eat more fruit, cereals, vegetables and wholemeal bread.
- Eat a wide variety of foods to ensure abalanced diet.
- Eat proper meals at regular intervals. Try not to skip breakfast or lunch.
- Exercise more regularly. Twenty minutes of brisk walking three or four times a week is sufficient exercise keep your body in good physical condition.
How many litres does the heart pump a day?
7600L
As well as genetic makeup what can attribute to heart problems?
Diet. A good diet and regular exercise together, greatly reduce the risk of heart problems in any one individual. High blood pressure is most directly linked to heart disease.
What is the most common form of pilot incapacitation?
Gastro
What foods should be avoided to reduce the chance of gastro?
Dairy, seafood and left out hot foods
In terms of humidity and temperature, what condone are comfortable for the human body?
21-27 degrees and 50% humidity
What are the three types of heat stress and how can they be combatted?
The first type of heat stress is likely to occur when your operating environment is too hot, defined as in excess of 32°C. The most noticeable effect will be tiredness, and it will become increasingly difficult for you to concentrate.
You may also suffer from heat exhaustion, which occurs when your circulatory system cannot compensate for blood vessels that have dilated to increase flow of heat out of your body via the skin. Drinking water is a good antidote for heat stress.
A second type of heat stress that can affect your performance can occur if you have had too much sun prior to a flight, through sun bathing or being outside without adequate protection. It can also occur when you have not had sufficient liquid intake. The effects ‘may be subtle and more difficult to notice, because your environment may be comfortable and you may feel well. However, your concentration may be lowered, leading to a decline in your decision-making ability.
A Third type of heat stress can occur when the temperature falls below about 10 degrees. If the temperature is very low, it is possible for your body to lose more heat than it can produce. Inextreme cases, this will cause shivering (a heat producer), drowsiness, and poor concentration. All of these will have an adverse effect on your performance, Hypothermia occurs when the body can no longer maintain its core temperature and its symptoms include impairment of thinking, apathy and eventually unconsicousness and death. The most likely cause of hypothermia is long immersion in cold water or unprotected exposure very cold environmental temperatures.
The best way to deal with potential problems from extreme temperatures is to be sensible. If it is very hot, drink a lot of water and keep your skin protected and wear light, lose fitting clothes. If it is very cold, make sure you are warmly clothed, a number of layers of fairly light clothes is much more effective than one thick coat because air trapped between the layers isavery good insulator. Do not rely on the heating system ofthe aircraft. Ifit fails, you could be in serious trouble.
Why is alcohol not recommended for keeping warm in cold conditions?
It gives a false sense of warmth while actually lowering your resistance.
What can dehydration cause?
Dehydration eventually leads to a malfunction of almost every bodily process including emotional disturbances and irrational decision making.
How much water should be consumed to prevent dehydration?
More than thirst dictates?
What are the early signs of dehydration?
The early symptoms of dehydration include drying of the nasal passages and a prickly sensation in the eyes.
What aircraft system can reduced dehydration at altitude?
The low relative humidity of air at high altitude can be avoided by the use of airconditioning
How long after giving blood should a pilot wait before giving blood?
24 hours
What health risks are increased by smoking?
Heart attack
Risk increased by 100%
If you have high blood pressure or high cholesterol, make that 200%.
If you are a woman on the contraceptive pill, make that 1000%
Stroke Risk increased by 100%
Gangrene Risk increased by 500%
cancer of the lungs, tongue, larynx, oesophagus and pancreas
What what chemical in cigarette smoke affects hypoxia?
The carbon monoxide in cigarette smoke reduces the blood’s oxygen carrying capacity, making the smoker more susceptible to hypoxia
Does air flow more easily in or out of the Eustachian tube?
Out, ergo pressurisation is easily achieved on a climb?
What is barotrauma?
The outer ear or ear canal is exposed to the outside atmosphere. Its function is to collect sound waves and direct them to the eardrum. The eardrum is a membrane stretched tightly across the ear canal [like the skin of adrum]. It separates the outer ear from the delicate balance and hearing apparatus of the inner ear. During a climb, the outside air pressure drops and the eardrum begins to bulge outwards. The eustachian tube provides a passage to allow the air behind the eardrum to leak out into the nasal cavity to equalise the pressure on either side of the eardrum.
During adescent the airpressure rises and the eardrum bulges inwards. The eustachian tube allows air toflow from the nasal cavity back to the inside of the eardrum to equalise the pressure. When the eustachian tube is blocked by mucus due to colds or flu, air no longer flows freely along this passage way. Unequal pressures cause the eardrum to stretch, causing severe pain and even rupture of the eardrum!
When should a pilot notify CASA of an inability to fly?
CASR 67.265 requires that if you suffer any injury or any other condition that may impair your ability to fly, you should advise the CASA or a DAME as soon as possible of the condition or injury. You should not fly until you are advised by a DAME that you fully meet the prescribed medical standards.
What are the main effects of deterioration due to ageing?
Hearing loss (higher frequencies in men) and longsightedness
When is it recommended a pregnant woman stop flying?
After the sixth month
What are the physical symptoms of air sickness and how can it be prevented?
Pale face, sweating, nausea and vomiting.
Fresh air on the face, looking at the horizon or becoming occupied with other thoughts or tasks can sometimes help.
How can anxiety be constructive?
It can heighten the body’s responses to stimuli and assist concentration by allowing the individual to disregard the irrelevant and focus on the immediate task
What is the purpose of depression in the body?
Depression is the body’s way of taking ‘time out’ during periods of disappointment or grief. It Should be accepted as a normal emotional response provided the reason for such feelings can be identified.
What is the purpose of fear in the body?
It is natures way of alerting us to situations which are threatening.
When is anxiety, fear or depression destructive?
When there is rational behind them
What can obesity contribute to?
Obesity can be a contributing factor in hypertension, gout, diabetes and heart disease - but most of all to heart disease
How much water does the body lose per day?
On an average day your body loses about one litre of water, but on a hot dry day you can lose as much as 5 litres!
What can ingesting too much salt cause?
Hypertension
Does any consumption of alcohol destroy brain cells?
Only if the drinking is heavy and long term. No evidence suggests that moderate drinking is harmful.
Long term, heavy consumption can damage the heart, liver and brain.
How can the rate of absorption of alcohol be reduced?
By consuming fatty foods
How much alcohol is metabolised by the liver?
~90% the rest is expired through breath, perspiration and urine at a constant rate of 1 standard drink per hour.
What can speed up the rate at which alcohol is removed from the body?
Nothing
How is alcohol absorbed?
Through the intestines and stomach into the bloodstream and to the brain.
Once the body has reached a BAC of zero, is the body still affected?
Yes, alcohol remains in the brain up to 24 hours after drinking?
What are the long term affects of alcohol?
Apart from the well known ‘hangover’ effects of nausea, headache, gastritis and thirst, frequent indulgence in heavy drinking puts a severe load on the entire system. Cancer of the mouth, oesophagus and stomach, damage tothe heart and liver are allwell documented long term effects of alcohol abuse. Many ofthese effects are actually more likely tobe related to the life-style of the heavy drinker as well as to the alcohol itself since the heavy drinker is often a heavy smoker on a poor diet with poor sleep pattems.
What is the maximum recommend alcohol consumption per week?
The maximum recommended alcohol intake over a period of one week is 21 to 28 standard drinks for a man and 14 to 21 standard drinks for a woman.
What are analgesics?
These are pain relievers. They may be used by pilots for the treatment of short-term pain such as headaches and muscular pain. If such pains persist, you should see your doctor.
Aspirin [trade names Aspro & Disprin] can cause stomach upset and, if taken to excess, can cause internal bleeding and kidney problems. Codeine (trade name Panadeine) can be addictive andcause constipation Paracetamol [tradenames Panadol & Dymadon] taken in excess can damage liver and kidneys.
What are antihistamines?
Used to help clear up congestion associated with colds, flu and sinus problems. They produce side effects [often pronounced] of drowsiness and degraded performance. They are definitely not to be used when flying!
What is ephedrine?
Often found innasal sprays. They can be incompatible with other medications, especially some blood pressure medications. The excessive use of nasal sprays can cause damage and irritation to the nose tissues worsening or prolonging the condition.
What are stimulants?
Amphetamines are illegal. They are used as ‘pep pills’ [Benzedrine]. Their side effects include short-tempered restlessness, disorientation, fits of anxiety, overconfidence and headaches.
Caffeine is widely used in beverages such as coffee, tea and coke. Too much causes sleeplessness and irregular heart rhythms. Itcan be habit forming.
What are antibiotics?
Antibiotics should normally have no detrimental effect on a pilots ability to safely carry out flying activities. However some individuals may have an allergic reaction to some antibiotics. Side effects may include diarrhoea. Since antibiotics are prescribed to treat some form of infection, the condition itself could be cause to refrain from flying. If you have been prescribed a course of antibiotics which you have never previously taken, it is generally recommended that a period of 24 hours should be allowed from the commencement of the course of antibiotic treatment to ensure that there is no allergic reaction.
What are tranquillisers?
Used to treat anxiety or tension, they should never be used without medical consultation. Their effectiveness diminishes with continual use and they are habit forming. Side effects include drowsiness, dizziness and an increased susceptibility to the effects of alcohol.
What are sedatives?
Most commonly used to treat sleep disorders, they should never be used without medical consultation. Side effects include dizziness, blurred vision, headaches and skin irritations. Some can be long-acting and produce a hangover effect. They are habit forming.
Can taking blood pressure medication disqualify a pilot from flying duties?
High or low blood pressure can be a reason for disqualification from flying duties. There are some medications for controlling blood pressure which are acceptable for pilots, however it is most important that you consult an approved aviation medical authority for advice before using such medications.
How is hyperventilation caused, what are its symptoms and how can it be alleviated?
Over breathing, exhaling too much CO2. Acidity reduction of blood leads to light headedness, dizziness, sweating, tingling, numbness in hands & feet. Hold Breath or voluntarily decrease rate of breathing to alleviate symptoms.
What are the rules for flying after diving?
No Decompression = 4 hours
Decompression stops, dive 4 hours = 48 hours
What is the Bends?
Decompression sickness.
While ever the high pressure within the lungs is maintained, the nitrogen remains harmlessly dissolved in the blood and tissues.
When the pressure is suddenly released by ascending to the surface too quickly, the nitrogen comes out of solution in exactly the same way as bubbles of gas suddenly appear within a soft drink when the cap is removed. Joints and muscles are usually first to feel the effects giving rise to stiffuess in the joints and rheumatic-like pains in the muscles. If the bubbles form in the spinal chord or brain, tingling sensations or paralysis may occur. If the ascending diver panics and holds his/her breath while ascending, the expanding air can rupture the delicate lung tissue forcing air into the blood stream. Rising quickly to the brain, this air-contaminated blood can cause unconsciousness or death.
Recompression is the only way to treat it. Flying will further reduce the pressure, thus exacerbating the condition.
Describe the inner workings of the ear, including the inner, middle and outer ear?n
Outer Ear: flap of cartilage. Hairs & wax producing cells prevent FOD from reaching the eardrum. Protects the eardrum for extremes of heat and cold.
Middle Ear: eardrum forms an airtight seal protecting the middle ear from the atmosphere. Eardrum vibrates – Hammer, anvil & Stirrup amplify & conduct vibrations to cochlea through the oval window. Mechanical energy to electrical of nerve impulses which is carried to the brain via the cochlea nerve. Middle Ear is vented to the atmosphere through the Eustachian Tube to the Upper Throat.
Inner Ear: Semicircular Canals detect acceleration in pitch, roll & yaw. Fluid washes over hairlike cells (cupula) which respond by sending nerve impulses to the brain, same as the cochlea. Otolith organ is made up of the utricle & the sacule. They detect horizontal & vertical accelerations respectively.
The cochlea is a small bony structure that looks a little like a snail’s shell. It is filled with fluid and contains tiny hairlike cells. The vibrations arriving at the oval window from the middle ear set up pressure waves which travel through the fluid of the cochlea. The hairlike cells respond to the pressure waves generating the nerve impulses which the brain interprets as sound. The hairlike cells are of various widths and each is ‘tuned’ to resonate at certain frequencies depending on its stiffness. Constant exposure to loud noise causes damage to these hairlike cells which is irreversible, even one episode of exposure to a very loud noise [like a gunshot at very close range], can cause permanent damage to hearing.
At what point does sound harm the human ear?
≥85dB for prolonged exposure. 120dB causes discomfort. 140dB is the pain threshold. Loud noises cause stress, loss of concentration, fatigue & reduction in efficiency.
How is sound intensity measured?
The intensity of sound is measured in units called decibels. One dB is the lowest change in sound level which a healthy, youthful ear can detect. Every increase of ten decibels indicates a tenfold increase in the intensity of sound. For example, a noise of 40 dB is ten times as loud as a noise of 30 dB!
When should hearing protection be worn?
As a general rule, hearing protection should be worn if the noise level is such that you need to shout to be heard of half a metre. Well fitting earplugs will provide areduction of about 25 dB, while a good quality, well fitting headset will reduce noise levels by about 40 dB
Why does hearing degrade with age?
Prolonged exposure to unnaturally loud noise levels
How does the brain orientate itself?
Visual, Vestibular and Postural cues all help maintain orientation.
