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Ex. 2. Read the information below and compare your answers with it
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Ex. 2. Read the information below and compare your answers with it.Uncontrolled DepressurizationUncontrolled depressurization is an unexpected drop in the pressure of an air- craft cabin. Generally uncontrolled decompression results from: human error; material fatigue; engineering fault; impact; or failure of the aircraft pressurization system. The speed and violence of the depressurization is affected by the size of the aircraft, the differential pressure between the inside and outside of the aircraft and the size of the leak hole. Below 10,000 ft, the reduced levels of oxygen have little effect on most crew and passengers but the higher the aircraft is, the greater the impact of lack of oxy- gen. Above 20,000 ft, lack of oxygen leads to loss of intellectual ability followed by unconsciousness and eventually respiratory and heart failure. Importantly, the time of useful consciousness reduces with altitude – at 35,000 feet it is less than one minute. There are three distinct types of decompression events in aircraft: explosive decompression; rapid decompression; slow or gradual decompression. Explosive depressurization takes less than 0.5 seconds. The cabin air may fill with dust and debris, and fog caused by drop in temperature and change in rela- tive humidity. Crew may be momentarily dazed or shocked, especially if the event was unexpected, and may therefore be slow to fit oxygen masks. The risk of lung trauma is very high, as is the danger from any unsecured objects which can fly around the aircraft. Rapid depressurization typically takes more than 0.5 seconds, allowing the lungs to decompress faster than the cabin. The risk of lung damage is still present, but significantly reduced compared to explosive decompression. Slow, or gradual, depressurization can only be detected by instruments. It oc- curs so slowly that it may go unnoticed before hypoxia sets in. The great danger of such depressurization is crew incapacitation. In the event of loss of pressurization, it is essential that the crew don oxygen equipment as soon as possible and descend immediately to an altitude at which they and the passengers can breathe without supplementary oxygen – convention- ally 10,000 ft. Decompression injuries: hypoxia (headaches, fatigue, shortness of breath, a feeling of euphoria and nausea); barotraumas (pains in the ears, eyes, dental pains); decompression sickness (confusion or memory loss (amnesia),headache, unexplained extreme fatigue, dizziness, vomiting and unconsciousness); physical trauma caused by debris and loose objects flying around the ca- жүктеу/скачать 1.29 Mb. Достарыңызбен бөлісу:
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