Abstract
Over time, there have been many scientific discoveries that have completely altered our lives positively. In the aviation industry, scientists dealing with aircraft design know well the importance of Boyle’s law application to flight operations. According to this law, the pressure of a gas is inversely proportional to volume (pressure decreases when volume increases and vice-versa) in a closed system (a system that can be isolated from the rest of the environment) if the temperature is kept constant.
This research paper looks at how Boyle’s law is important in ensuring the safety of passengers and airplanes in general. The research looks at a well-documented article on the importance of Boyle’s law in preserving the health of the passengers. Most of the research carried out in the paper is gotten from secondary sources on the subject. The research paper aims to educate various stakeholders on the importance of Boyle’s law in flight operations.
Introduction
Over time, there have been many scientific discoveries that have completely altered our lives positively. In the aviation industry, scientists dealing with aircraft design know well the importance of Boyle’s law application to flight operations. According to this law, the pressure of a gas is inversely proportional to volume (pressure decreases when volume increases and vice-versa) in a closed system (a system that can be isolated from the rest of the environment) if the temperature is kept constant. This can be represented mathematically as:
PV=constant
Where:
- P represents the pressure as V represents volume. (Maddux, n.d)
Relation of Boyle’s Law to Flight Operation
Flight operations operate in an environment of air gases meaning that Boyle’s law comes into play in almost all aspects of flight operations. More significantly, two parameters whose relationship has been described by Boyle’s law i.e. pressure and volume keep changing during descent, ascent and movement in the air space meaning that Boyle’s law needs to be considered for flight safety. The human body on the other hand needs to maintain the process of continuous gaseous exchange to stay alive hence calling for a need of maintaining conducive conditions of gas pressure, the concentration of oxygen and gas volume for the human body to survive during flight.
Aircraft designers recognized the fact that the human body on its own can not withstand varying atmospheric conditions of air volume, air pressure and concentration of oxygen at changing altitudes hence the need to design a machine for flight transport. (Levine, 1978) Moreover, engines and other devices involve combustion and other physical and chemical processes during flight hence the need to consider Boyle’s law for safe flight. It can therefore be seen that Boyle’s law is very significant in many respects as concerns flight safety. (Iglesias, 1974, p. 276)
According to an article titled Altitude Physiology, cabin pressurization is one area where Boyle’s law is applied. (McLellan, n.d, p. 4) Since atmospheric pressure decreases with an increase in altitude, Boyle’s law predicts that an ascent will be followed by gas expansion while a descent will be followed by gas contraction. This implies that Boyle’s law is bound to affect any enclosed environment containing air like internal body air spaces including sinuses, the ear, digestive and respiratory tracts among others. There is therefore a need to remove gas in these body organs so that it does not expand due to decreased pressure to strain tissues. This especially can have adverse effects on patients with problems like asthma and pneumothorax. Moreover, medical equipments in an aircraft could also be affected in a similar way due to gas expansion. (McLellan, n.d, p. 4)
Several problems can be experienced by the cabin crew because of an increased expansion of gas that comes with decreasing pressure. This includes hypernoxia and hyperventilation. Patients with these problems may show the following signs, confusion, numbness dizziness, clammy skin and nausea. Although these conditions have almost similar signs, the major difference is that hypernoxia may show up later as compared to hyperventilation. Another condition common in flights because of decreased pressure (meaning possibility of decreased amounts of oxygen) is hypoxia.
The same environmental conditions leading to hypoxia can lead to a decrease in the tension of arteries a condition referred to as hypoxemia and a rise in the concentration of carbon dioxide in the blood a condition referred to as hypercapnia. All of these conditions are caused in one way or another by a decrease in atmospheric pressure. For example, hypoxia conditions can be experienced because of the inefficient gaseous exchange process at the membrane of alveolus. Decreased atmospheric pressure, decreased oxygen concentration in the air and obstruction of internal air paths can lead to this condition. (McLellan, n.d, p. 10)
The effect of loss of pressure and concentration of oxygen is well illustrated in a plane mishap that occurred on October 25th 1999, which occurred at Aberdeen South of Dakota. The details and investigations 0f this accident are contained in an NTSB database accident no. DCA00MA005. Investigations revealed that this crash was caused by the hypoxia of the pilots and all crewmembers. Observation of the wreckage revealed that the oxygen bottle had malfunctioned. Moreover, sample tests of the captain tissues showed large concentrations of chemicals that occur during oxidation in limited amounts of oxygen. (NTSB, 1999)
Using pressurized aircraft is considered the best way of abating the effects of a decreased atmospheric pressure and therefore the best way of decreasing the occurrence of health conditions associated with decreased atmospheric pressure in the flight crew. In this system, an artificial environment containing a desirable atmospheric pressure in the cabin is created and maintained. The structure of this system is designed to cope with the pressure difference between the cabin and the atmosphere. This system takes in air from outside; compresses it before delivering it to the cabin.
To maintain a constant pressure in the cabin, the rate of movement of air out of the cabin is controlled. An example of a method that is commonly used to control cabin pressure includes the Isobaric system that creates a constant pressure in the cabin as the atmospheric pressure decreases. It is very important to carry out routine maintenance of this system apart from providing alternative oxygen masks that also need to be maintained regularly. Investigations from the crash revealed that there had not been sufficient records monitoring the functioning of these systems. (McLellan, n.d, p. 10)
Apart from cabin pressurization, medical personnel in flights can use several techniques to monitor the condition of flight crew. It is important to note that cabin pressurization can fail sometimes and that people are affected differently in low atmospheric conditions depending on their health. Medical personnel use techniques like administration of oxygen on patients using oxygen masks, monitoring of the rate of breathing among other methods. Moreover, it is also important to monitor the cabin pressurization system for any malfunction. (McLellan, n.d, p. 14)
Conclusion
Boyle’s law is one of the most important laws that need to be considered in life. Its principle is applied in aircraft design including aircraft structure, which is designed to overcome difficulties that are bound to come with a decreasing pressure during ascent and an increasing pressure during descent. Changing weather conditions that affect pressure during flight also need to be considered. More important, it is important to ensure that flight crew travels under safe conditions health-wise and that they do not suffer from conditions associated with pressure and volume changes in the cabin and their bodies as much as possible.
References List
Iglesias R, Cortes MDCG, Almanza C. (1974) “Facing air passengers’ medical problems while on board”. Aerospace Med, Vol.45, pp.204–206.
Levine, Ira. N. (1978). “Physical Chemistry” University of Brooklyn: McGraw-Hill Publishing
McLellan, H. (n.d) “Alberta Shock Trauma Air Rescue Society”. Altitude Physiology. Alberta Stars, pp. 2-25
Maddux, J. (n.d). Flight Physiology 101. 2010, Web.
NTSB. (1999). “Aircraft Accident Brief”. DCA00MA005. Web.