Sunday, September 22, 2019

Designing a Safer Passenger Aircraft Essay Example for Free

Designing a Safer Passenger Aircraft Essay Aircrafts have become more advanced and fast, but they are drastically affected by ignorance and design incapability. However these structures can fly with more than 200 passengers and heavy cargo, but when they crash, they take away with them many lives and damage valuable property. To prevent such loses several aviation safety agencies like EASA(European Aviation Safety Agency) and FAA(Federal Aviation Administration) have been functioning. These agencies implement and monitor safety rules for aircrafts. They also certify and approve organizations involved in the design, manufacture and maintenance of aeronautical products. Safety of an aircraft depends on every smallest possible detail of it. For designing a safer passenger aircraft a lot of investigation has to be done on flight failures, to prevent such failures. There are four main aspects considered while designing an aircraft: Aerodynamics, Propulsion, Structures and materials, Stability and control. An overview on the design of a fixed wing aircraft: The structure of an aircraft is configured as follows: A fuselage is a long cylindrical body with tapered ends to make its shape aerodynamically smooth. Fuselage carries flight crew, passengers, payload, fuel and engine. Fuselage also holds a large wing which provides sufficient lifting force to the aircraft due to the shape of its cross section (aerofoil). This large wing has ailerons to control rolling motion. The vertical stabilizers present at the rear end of the aircraft, stabilizes the yaw motion and horizontal stabilizers stabilizes the pitch. Elevators are mounted to the horizontal stabilizers and it controls the pitch of the aircraft. Engines provide the trust required for the aircraft. The landing gear is a set of wheels that supports the plane on ground. Control system of an aircraft: Yoke controls the pitch and roll motion of an aircraft. Rudder pedals control the rudder and thus it controls the motion about the yaw axis. Throttle lever controls the thrust produces by each engine and brakes slow or stop the airplane on ground. There are controls for flaps and spoilers. A tiller is used to steer the plane on ground. An automatic flight management system helps pilot in maintaining altitude or mode of flight. Analysis of investigation reports of some airplane crashes and preventive measures in design: A Pilatus aircraft crashed near Bert Mooney airport in July, 2011 due to loss of control. Investigation reports showed that there was icing within the fuel system causing low fuel pressure state as fuel system icing inhibitor was not added to the fuel before flight. All jet fuels contain trace amounts of water that form crystals and block the fuel system. Icing inhibitors decrease the freezing point to about -40? C preventing water from freezing. Some chemical detector can be introduced that could detect the concentration of icing inhibitors present in the fuel. An alarm can also be added to the electronic system of the aircraft which will remind the pilot of adding icing inhibitors while refueling. Aircrafts flying in cold weather develop icing on wings which greatly impair wings ability to generate sufficient lift. Air Florida flight crashed on take-off in January, 1982 as a result of ice on its wings. Modern airliners are designed to prevent accumulation of ice on wings, engines or tails either by routing heated area towards icing or by using inflatable rubber tubes that expand and break off any accumulated ice. Similar method can be used in the design or the accumulated ice can also be removed by sending small amplitude vibrations to the accumulated area. A Boeing cargo airplane experienced ground fire before engine start-up at San Francisco International airport. Investigation blames the design of the supplemental oxygen system hoses and the lack of positive separation between electrical wiring and electrically conductive oxygen system components. The lack of positive separation allowed a short circuit to breach a combustible oxygen hose, release oxygen, and initiate a fire. This can be taken care of in the design and either separation between the oxygen hoses and wiring can be increased or insulation of wiring can be made more strong. Composite materials used in structure of an aircraft consist of layers of fibers embedded in a resin matrix. These layers separate from each other when subjected to cyclic stress and they lose strength. This failure is not shown on the surface. An amphibian plane suffered a structural failure in Florida. The right wing of the aircraft separated during normal flight due to lack of maintenance. Ultrasound based instrument method is used to detect such failures in designing a safer aircraft. As in Air France Concorde crash case, pilot detected fire very late. Installation of video cameras at critical places can be a preventive measure as pilot will be able to keep a watch on plane if there is no other failure detecting mechanism. During high speed landing or take-off extreme pressure and heat build-up in tyres and in such conditions tyres burst. This is equivalent to explosion of 4-5 dynamites. This could damage the fuel tank or engines and even initiate a fire. Some cooling mechanism within tyres can be used to prevent such conditions of high temperature and pressure. Above safety concerns and all other governing factors can be considered to design a safer passenger aircraft. Apart form these problems foreign object debris, positive lightning, bird strike, volcanic ash can also be taken care of while designing an aircraft. Ground based navigation aids can also be improved by improving GPS systems and some backup modes of communication may help in significant reduction in air crashes due to lack of information and misleading.

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