Instituion
1. What is the potential impact of supersonic transports (SSTs) on the ozone layer?
An alarming ozone loss has been reported in the past decades, and studies showed that this global problem is attributed largely to human activities. Advancement in technology resulted in the development of high-speed air transport that are economically competitive compared to other forms of aircrafts. There is, however, the associated risk that supersonic transports can impact in the destruction of the ozone layer due to the large amount of atmospheric pollution that it emits. The Massachusetts Institute of Technology carried a study on the possible effect of SSTs on the stratosphere, particularly to the ozone layer.
a) Oxygen balance upset. Researchers pointed out the likelihood that the SST would deplete the oxygen of the stratosphere. This is attributed to the assumption that one SST burns about 66 tons of fuel in an hour and maneuver for about 7 hours a day in the stratosphere (Johnson, 1972). While studies have shown that oxygen depletion in the atmosphere is not likely to occur, it was found that its reserves have gradually declined.
b) Excess global carbon dioxide. There is also an indication that the carbon dioxide released by the SSTs can destroy the ozone layer based on the findings that 500 SSTs can release about 5 X 108 tons of carbon dioxide in the upper atmosphere two years time (Johnson, 1972).
c) Radiation hazards. Further report suggested the possibility of radiation hazards as it was theorized that the water released by the SSTs can cause the depletion of the stratospheric ozone (Johnson, 1972). Scientific calculation resulted in the conclusion that there is an expected impact in the ozone layer from the water vapors that are introduced into the atmosphere.
d) Weather modification from water vapor and particulates. Studies revealed that the sulfur found in the SST fuel will be converted into a sulfur dioxide, and this element can cause the drastic depletion of the ozone layer (Ward, 2009).
2. Look up the term ‘anoxia’ and ‘hypoxia’. Explain why these concepts are important in aviation. How to modern aircraft address these conditions? What regulations are in place to protect aviators (and passengers)?
Anoxia and hypoxia refer to the deprivation of oxygen supply in the body. These two concepts are important in aviation because they are among the problems that are considered to impair the mental and physical ability of the pilot. It was established that while pressure and temperature are important, “the lack of oxygen is the greatest single danger to man at high altitudes” (DIANE Publishing Company, 1974). It is also unfortunate that the victim of oxygen deprivation, are not likely to recognize that it. Oxygen deprivation is said to first impact the brain, and immediately dulls the victim making them disoriented due to the inability of the mind to function properly. There are several accidents attributed to the loss of the pilot’s critical ability due to oxygen deprivation, thus modern aircraft should address this concern specially that this phenomenon usually occur without warning or pain.
The dangers associated with oxygen deprivation resulted in the need of modern aircraft to address this problem fully. For the Aircrew, an appropriate and sufficient training is required to ensure that they have acquired the instinctive response to put on oxygen mask when the initial signs of decompression happen. For the pilots, a sequential response should be ensured in order to maintain control of the aircraft.
The research found that most pilots often do not consider the need for portable oxygen. The Federal Aviation Regulations Part 91.211 indicated several guidelines as to the use of supplemental oxygen by Aircrews. For instance the FAR Part 91.211 is clear about the rule that civil aircraft registered under the U.S shall be operated over 15,000 feet cabin pressure altitude, without providing each occupant of the aircraft with supplemental oxygen (Aircraft, 2016).
3. A Foucault pendulum is often used to demonstrate the Coriolis effect. Research and describe what a Foucault pendulum is and how it works. Furthermore, explain how it demonstrates the Coriolis effect.
Foucault pendulum is simply referred to as a device that was often used to demonstrate how the earth rotates. The Foucault pendulum can show the rotation of the earth when the pendulum, which is based on a fixed plane, swings while the Earth rotates below. However, in order for the device to be exact, extreme caution must be observed to make sure that the device is not impacted by any other forces aside from the pull of gravity. In observing heavy pendulums which have long and rigid wires, they were found to oscillate for a much longer time. However, the impact of air resistance will eventually stop the movement. There is a need to use electromagnetic drives to keep the movement of the pendulum, and this can be compared to the force that affects the rotation of the Earth called the Coriolis force. This explains why “weights dropped from tall towers fell slightly to one side rather than straight down” (Sparkes, 2013).
While the Coriolis force may not be perceptible by human, this force can have an effect on “bodies that move over great distances, such as an air mass or body of water” (Pilot’s, 2009). Another noted effect of the Coriolis force is that it refracts air to the right of the North Hemisphere, thereby triggering it to trail towards a bent path instead of following a straight line. While the amount of refraction may differ because it is largely dependent on the altitude, it is observed to be greatest at the poles, and reduces to zero as it reaches the equator. The extent by which the Coriolis force differs is also affected by the speed of the moving body, and it was found that there is greater difference with greater speed. Consequently, in the Northern Hemisphere, the rotation of the Earth moves the air to the right and alters the general movement of the air (Pilot’s, 2009).
4. Do some research on aircraft navigation and document the effects of Coriolis in detail.
The Coriolis force is a description on how the rotation of the Earth deflects the movement of the winds and the currents in the surface of the ocean. This is the force that gives the impression that a supposed straight path of flying object eventually follow a curved path. The Coriolis force leads to an illusion that may cause pilot disorientation and loss of control.
The cause of a Piper Cherokee Six accident on September 26, 2002 that resulted in the death of its six passengers was not completely established. However, investigation suggested “that the pilot experienced some degree of spatial disorientation during the turn as a combined result of the maneuver, and associated head movements” (Newman, 2007). Another instance when pilot disorientation affected the ability of the flier occurred on September 6, 2005 when a Robinson R22 helicopter was maneuvered by an underqualified pilot. The engine collided into the ground, which fatally injured both the pilot and the lone passenger. It was found that the pilot “became disoriented at a height from which recovery was not possible before the helicopter impacted the ground” (Newman, 2007).
In another instance, on April 27, 2001, a Bell 407 helicopter was on its way to conduct a search and rescue operation for a distraught vessel. During the operation, the aircraft plunged into the water, fortunately, the crew members were able to survive the accident. The subsequent investigation suggested that the pilot applied an inappropriate technique in descending. While the accident can be attributed to the pilot’s lack of recent exposure to over-water night operation, it was also possible that “false horizons may be seen when climbing out of the weather and arriving on top of an unrecognized sloping cloud bank” (Newman, 2007).
5. You are in a pressurized cockpit that undergoes rapid decompression. Fog forms suddenly in the cockpit, then dissipates. Explain.
As part of its safety and environmental control, modern aircrafts are built with cabin air systems that can regulate pressurization, flow of air and its filtration, as well as temperature. These systems are not only intended to have a safe and comfortable cabin environment, but also to offer protection to all the occupants from the risks associated with high altitudes. It is to be noted that modern aircraft are designed to be able to operate at higher altitudes than before, thus the increased risks that are associated with decompression, for instance, there is a risk that hypoxia may be experienced by the crew and the passengers (AIRBUS, 2007).
The following signs are indicative of Rapid/Explosive decompression:
A loud explosion, blow or a clap that is the due to the abrupt contact between the masses of internal and external air;
The sudden appearance of cloud of fog within the cabin, which is due to the fall of the temperature, and the eventual change of humidity;
There is also the rush of air, as the air leaves the cabin;
An observed drop in temperature, this happens as the temperature within the cabin matches with the temperature outside (AIRBUS, 2007).
On the other hand, if the decompression was caused by the breach in the structure of the aircraft, the signs include the ejection of unsecured items within the immediate area. One may also notice that debris fly around the cabin, and loose items become projected from everywhere. There may be a limited visibility due to dust, in addition to confusion due to the thickness of fog and the inability to communicate (AIRBUS, 2007)
References
AIRBUS. (2007). Cabin decompression awareness. Retrieved from http://www.airbus.com/fileadmin/media_gallery/files/safety_library_items/AirbusSafetyLib_-FLT_OPS-CAB_OPS-SEQ09.pdf
Aircraft Owners and Pilots Association. (2016). Oxygen use in aviation. Retrieved from http://www.aopa.org/Pilot-Resources/PIC-archive/Pilot-and-Passenger-Physiology/Oxygen-Use-in-Aviation
DIANE Publishing Company. (1974). Medical handbooks for pilots.
Johnson, H. (1972). The effect of supersonic transport planes on the stratospheric ozone sheild. Boston College Environemental Affairs Law Reveiw, 1(4), 735-781. Retrieved from http://lawdigitalcommons.bc.edu/cgi/viewcontent.cgi?article=2059&context=ealr
Newman, D. (2007). An overview of spatial disorientation as a factor in aviation accidents and incidents. ATSB Transport Safety Investigation Report.
Pilot's Handbook of Aeronautical Knowledge. (2009). Government Printing Office.
Sparkes, M. (2013). What is Foucault's Pendulum? Retrieved from http://www.telegraph.co.uk/technology/google/google-doodle/10317223/What-is-Foucaults-Pendulum.html
Ward, P. (2009). Sulfur dioxide initiates global climate change in four ways. Thin Solid Films, 517, 3188-3203. Retrieved from https://www.ozonedepletiontheory.info/Papers/Ward2009SulfurDioxide.pdf
