Free Essay

Mid Air Collisions

In: People

Submitted By saunders
Words 2277
Pages 10
Mid Air Collisions

Brian Saunders
Human Factors
David Miller
June 18, 2011

No pilot is immune from a mid air collision and it is one of the pilot’s worst nightmares. Although rare, mid air collisions are a tragic event of when two airplanes collide with each other during flight. Statically speaking, nearly all mid air collisions happen during daylight hours and in Visual flight rules (VFR) conditions and astonishing enough, the greater part of mid air collisions take place within five miles from the airport. The first recorded mid air accident occurred at an air show in the city of Milan, Italy on October 3, 1910. Even though it was a miracle that both pilots survived the accident, mid air collisions would continue to occur without this favorable of an outcome. By the nineteen fifties, and with the introduction of the new generation commercial airplanes, people started to travel more by air than by train; a spur of change was needed.
Between the years of nineteen fifty-six and nineteen fifty-eight, two high profile mid air collisions accidents occurred in uncontrolled air space. The accident between a United DC-7 and a TWA Constellation collided and crashed on 30 June 1956 over the Grand Canyon in Arizona killing all one hundred and twenty-eight passengers and crew. The second notable mid air collision was between a United Airlines Douglas DC-7 aircraft with forty-two passengers and two crew and a United States Air Force North American F-100 Super Sabre supersonic jet fighter aircraft carrying two crew members. They collided over Las Vegas and crashed in the desert killing all forty-nine individuals. These accidents brought a lot of attention to the general public on flying safety, uncontrolled airspace, and the lack of modernization of equipment of the air traffic controllers.
With these chains of events, this led to the increased funding to modernize air traffic controllers systems and hiring and training more air traffic controllers. Additionally, this led to the passing of the Federal Aviation Act of 1958 into law. This law dissolved the Civil Aeronautics Administration and creating the Federal Aviation Agency which gave the Federal Aviation Agency unprecedented and total authority over the control of American airspace, including military activity, and as procedures and air traffic controllers facilities were modernized, airborne collisions gradually subsided. But as the skies become more crowded the chances of such probable accidents will increase at a rate of two collisions per year. This became an actuality on November 12, 1996 when an older Saudi Arabian 747-100B jumbo jet airliner which was not equipped with a TCAS system was in route to Jeddah, Saudi Arabia collided with a Kazakhstan Airlines IL-76 freighter over New Delhi, India. This accident cost the lives of three hundred forty-nine people and remains the worst mid air collision to date.
There are several factors why mid air collisions take place. In the mid air collision over the Grand Canyon in nineteen fifty-six, the National Transportation Safety Board concluded that that the probable cause of this mid-air collision was that the pilots did not see each other in time to avoid the collision. Although the National Transportation Safety Board could not determine why the aircrew could not see each other, the investigators suggested it could have resulted from a combination of human factors such as Intervening clouds reducing time for visual separation, visual limitations due to cockpit visibility, and preoccupation with normal cockpit duties, preoccupation with matters unrelated to cockpit duties and physiological limits to human vision reducing the time opportunity to see and avoid the other aircraft. Furthermore, the likely hood for a mid-air collision is augmented by miscommunication, error in navigation, and deviations from flight plans.()
To aid in the prevention of mid air collisions, the Traffic Alert and Collision Avoidance System otherwise known as TCAS hardware and software and or other proximity warning devices were developed in the nineteen fifties and implemented in the mid nineteen seventies and provides pilots with electronic eyes for pilots giving them an enhanced view of nearby flight traffic. It wasn’t until nineteen eighty-one when the chief of the Federal Aviation Administration J. Lynn Helms committed the resources to the Federal Aviation Administration to develop an airborne collision system by nineteen eight-five. At this time and with help from the congressional legislation in nineteen eight-seven the Federal Aviation Administration mandated the installation of Traffic Alert and Collision Avoidance System II on all airliners by the end of nineteen ninety-three.(Genie). Its design was to enhance cockpit awareness of nearby aircraft and aid in the prevention of mid air collisions. It consists of hardware and software that are integrated into other systems in the cockpit and includes a display showing the relative positions and altitudes of aircraft up to thirty-five nautical miles from each other. For example, when aircraft comes within a certain range of each other, TCAS sounds an alarm and issues conflict advisor and prompts pilots to make evasive maneuvers through resolution instructions, acting as a backup to the ground air traffic control system’s separation processes. The Traffic Alert and Collision Avoidance Systems has proven to be an important safety tool in the aviation industry and has substantially reduce the steadily increasing threat of mid-air collisions from the past. Traffic Alert and Collision Avoidance System is now the world standard collision avoidance system for commercial aircraft.
In early aviation the term “see and avoid” was the only deterrence in preventing mid air collisions while flying in uncontrolled airspace, but as we moved to the jet age of the airline industry, aircraft began to travel faster and technology improved on mid air collision avoidance. Mid air collision avoidance software and hardware was developed. There are several types of Traffic Alert and Collision Avoidance Systems (TCAS) in the market, but I will focus on the three that are primarily used. The first one is TCAS one was the first generation of collision avoidance; it is mandated on all aircraft with ten to thirty seats and is used to accommodate the smaller planes that are used in general aviation and regional airlines. The next type of Traffic Alert and Collision Avoidance System is the TCAS two version seven. This version is the latest reversion of the Traffic Alert and Collision Avoidance System and is used in the United States, Japan, Australia, and most of Europe. It is a more advanced system than the TCAS one for which it analyzes the projected flight paths of approaching aircraft and issues an advisories to the aircrews. Traffic Alert and Collision Avoidance System two is required in all international aircraft, aircraft with more than thirty seats or weighing more than thirty-three thousands pounds. The last example I would like to highlight is the Portable Collision Avoidance System; this type of avoidance system was developed in nineteen ninety-nine and is generally used for flight schools, flying clubs, rented planes, or pilots who own their own aircraft. It provides the same similar functions as the Traffic Alert and Collision Avoidance Systems and has grown in popularity due to the fact it is portable and at a cost of five hundred to two thousand dollars, it is considerable less expensive than the Traffic Alert and Collision Avoidance System which costs between one hundred fifty thousand to two hundred thousand dollars.
When an aircraft is equipped with Traffic Alert and Collision Avoidance System it picks up and sends a signal to its aircrafts transponder receiver, these transponders receivers are miniature in size and serves as the same functions as the transponders used by air traffic controllers in controlling air traffic around airports. After the aircrafts transponder receives the signal it sends it to the cockpit and gives the aircrew vocalized alarm signals. There are two types of alarms signals the Traffic Alert and Collision Avoidance System provide sto the aircrew. The first one is traffic advisory; this advisory provides the aircrew with a spoken warning in the form of "Traffic, Traffic". This audio message is usually received when aircraft are within thirty-five nautical miles of each other. When this happens, the aircrew will not maneuver there aircraft in response to a traffic advisory, but will attempt to establish a visual contact, and be prepared to maneuver the aircraft if a resolution advisory occurs. The second alarm sent by the transponder can send to the aircrew a resolution advisory; this type of advisory is a more serious one. This advisory is an urgent threat prediction that traffic aircraft will enter the Traffic Alert and Collision Avoidance System collision airspace within approximately twenty to thirty seconds. When Traffic Alert and Collision Avoidance System issue a resolution advisory several things will happen, for example: a voice alert will sound, vertical guidance will be displayed, and symbogly will be displayed to the aircrew to make the necessary actions. Once the aircrew is notified of resolution advisory aircrews will respond without delay and maneuver as indicated by the Traffic Alert and Collision Avoidance System, unless it jeopardizes the safety of the airplane. Additionally, aircrew will always follow of resolution advisory alarm even if there is a conflict between the resolution advisory and an Air Traffic Control instruction to maneuver. Lastly, aircrew never maneuver in the opposite sense to an of resolution advisory, nor maintain a vertical rate in the opposite sense to a resolution advisory. Once the resolution advisory has been resolved or as permitted by workload by the aircrews, the aircrew will inform the appropriate air traffic controller of the deviation. Overall, Traffic Alert and Collision Avoidance System is a tool designed to prevent midair collisions between aircraft is used as a last resort.
As with any technology the Traffic Alert and Collision Avoidance System is not infallible. Pilots still need to be alert and have situational awareness when flying an airplane. Some problems associated with the Traffic Alert and Collision Avoidance System is that in order for the Traffic Alert and Collision Avoidance System to work it must be turned on and operating. In addition, it needs to be set up correctly. To further complicate the matter, smaller planes are not required to have a Traffic Alert and Collision Avoidance System whereas the larger aircraft are mandated by law. The commercial aviation industry feels that all aircraft operating in the United States should have a Traffic Alert and Collision Avoidance System built in and operating. But this can become very costly for the recreational pilots. Another concern with the Traffic Alert and Collision Avoidance System is that it doesn’t provide horizontal avoidance. Although it does call out voices to aircrew to perform vertical maneuvers for example, “CLIMB! CLIMB!” or DESEND! DESEND!” or “ADJUST VERTICAL SPEED:” it does not call out any horizontal messages. The aviation industry feel an improvement could be made to include voices like “BANK RIGHT AND DESEND!” or “BANK LEFT AND DESEND!” There is also was some confusion whether follow the instructions from the air traffic controller or the Traffic Alert and Collision Avoidance System resolution advisory. There are still some pilots that feel that the air traffic controllers will take care of them and others feel that the Traffic Alert and Collision Avoidance System was put into place to take care of them. But this wasn’t the case in this notable mid air collision over Germany on the fateful day on 1 July 2002 when a Tupolev Tu-154M passenger aircraft Flight 2937 flown by Bashkirian Airlines enroute to Barcelona collided with a DHL Boeing 757-23APF cargo aircraft over Uberlingen, Germany killing all seventy-one passengers and crew. At the conclusion of the investigation on 19 May 2004, the German Federal Bureau of Aircraft Accidents Investigation determined that the probable cause of the accident lay within the Swiss air traffic control system in charge and problems with the use of the collision warning system. The Boeing aircraft relied on the Traffic Alert and Collision Avoidance System resolution advisory and descended his aircraft and the Tupolev also descended by given guidance from the air traffic controller and eventually collided with each other. What makes this event more tragic is that the air traffic controller who was named as causal to accident was murdered seventeen months after the accident by an individual who lost his wife and two children in the collision. Another incident worth noting happened in Japan on 31 January 2001 when two JAL’ aircraft; an Boeing 747 and a Douglas DC-10 nearly collided due to the air traffic controller and Traffic Alert and Collision Avoidance System resolution advisory contradicting each other. As the Boeing 747 descended following the instructions of the resolution advisory, the Douglas DC-10 was told by the air traffic controller; who was tremendously busy at the time to also descend. The Boeing 747 pilots managed to avoid the accident by a narrow margin by adjusting the aircrafts pitch. Miraculously there were only injuries in this incident, it could have been worse. With both planes involved there were a total of six hundred and seventy-seven passengers and crew on board. This would have been by far the worst midair collision to date.
Although the Federal Aviation Administration states that when a situation where a conflict arises between Traffic Alert and Collision Avoidance System resolution advisory and air traffic controller, Traffic Alert and Collision Avoidance System resolution advisory must take priority. As mentioned above, this is not always the case in which things happen. Also worth mentioning, the two stated examples are classic examples of SHEL model liveware-liveware and liveware-software.…...

Similar Documents

Free Essay

Traffic Alert and Collision Avoidance System and the Human Element

...Alert and Collision Avoidance System and the Human Element Terry D. Gilfillan Embry-Riddle Aeronautical University Abstract This paper describes the history of the Traffic Alert and Collision Avoidance System (TCAS). It will discuss the types or categories of and the operation of the system of TCAS, to include the components involved, how the system interacts with other aircraft that are equipped with TCAS, and the related warnings and/or notifications of the system. Also discussed is the human element related to the operation and interaction of TCAS. These human elements include the human senses and situational awareness. Traffic Alert and Collision Avoidance System and the Human Element Two planes collide in the skies somewhere over the Grand Canyon on 30 June 1956. Because of this collision and many others, the aviation industry came to the realization that some type of system or process had to be created to help with the prevention of these collisions. Several companies began the design of collision avoidance systems, however it wasn’t easy, as they had to overcome two specific obstacles. First, the air carrier would have to install or outfit their fleets with the new hardware for the system and that would prove to be very expensive. The second obstacle; there would still be a lot of planning and development to do before TCAS would be up and running efficiently. That being said, TCAS was still in development on 31 August 1986 when a midair collision between......

Words: 2692 - Pages: 11

Free Essay

The Collision

...The Collision It was a raining day of winter, 1999 when I was driving on a wet slippery road of i680 north going to toward work. The sides of the freeway were flooded and too many cars tend to be going the same direction as mine. It was heavy traffic and other driver’s frustration appeared; when they were swerving their cars left and right trying to make their way out of traffic. I had my radio on and the news was about a car accident on San Mateo Bridge, which already started my day off wrong from that moment. As I was counting down the miles toward my destination, driving my car on the carpool lane going 65 miles per hour which was the legal speed limit for the freeway. Cruising on the far left lane, driving a 2005 black Jeep Cherokee that had four large tires which made me higher and oversee the whole view of the freeway. The incident started when I took a quick glance over my right shoulder and saw a blue, shiny-rimmed Toyota Runner, suv spinning out of control. The car instantly took my attention; the car was at the very far right lane so at the moment I did not doubt that the driver was going to make his way towards me immediately. Because it was raining hard and the road was wet which made him to slide all the way to the far left lane. At first he hit the concrete freeway dividers suddenly, I instantly slammed my breaks until I saw smoke coming out from the tires and then blew up. He spun 180 degrees and stopped facing the incoming traffic. I look at......

Words: 895 - Pages: 4

Free Essay

Galaxy Collisions

...galaxies interacting. You can see they are being distorted by the gravitational interaction between them.” 2 The second effect is collision, as galaxies become fairly close together, its might merge together and collide. This merging/collision is sometimes known as a pair, or as a companion of one another. Sometimes smaller galaxies can just merge with larger ones; this is called the ripple effect collision. “The Cartwheel galaxy is an example of this type of collision. The outer ring of blue stars in this galaxy indicates a ripple of star formation resulting from the collision.” 1 The reasons for the collision is based on many factors, for example the number of galaxies engaged, their size, mass, type, the distance between them, their gravitational force, and so on. As we just saw how galaxies collision, a common question will be could stars also collide?, well logical people will say yes, cause what’s a galaxy it’s a collection of millions and trillions of stars, and we proved that galaxies collide so that basically means stars do as well. In fact stars are very far away that the collision between them are very rare. “In fact, the Milky Way Galaxy is colliding with the Sagittarius Dwarf Galaxy right now” 2 In additional to our milky way collision, the Antennae galaxies which is made up of two spiral galaxies, are also in the progression of collision, and as mention the process take hundreds of millions of years. “When two galaxies interact, clouds of gas inside......

Words: 730 - Pages: 3

Premium Essay

Robotics Collision Lab

...Collision Lab Sierra Callwood 03/05/2014 Mr. Weidenboerner Period 7 Purpose: To explore sensors and use them to knock down a box filled with bean bags without going over the edge of a precipice. Hypothesis: I think that designs with a high point of impact and and sensor placed out in front of the robot will have the best results. Group 2 | Trial | Distance from the Egde | 1 | 28 mm | 2 | 32 mm | 3 | 35 mm | 4 | 22 mm | 5 | fail | Average | 32 mm | Competion | Group | Average | 1 | 23 mm | 2 | 32 mm | 3 | fail | 4 | 7 mm | Program Flow: 1. #Include “Main.h” 2. 3. void main (void) 4. { 5. int limitswitch; 6. 7. // 0 is pressed 8. // 1 is not pressed 9. Wait (5000) 10. while (1==1) 11. { 12. limitswitch = Get DigitalInput (1); 13. if (limitswitch==1) 14. { 15. Set Motor (1.0); 16. Set Motor (10.0); 17. Wait (200) 18. } 19. else 20. } 21. Set Motor (1.-40); 22. Set Motor (10.40); 23. } 24. } 25. } Results: Group 1 cam in second place with an average of 23 mm from 5 trials. Group 2 (my group), came in third place with an average of 32 mm from the edge of the table. Group 3 came in last place with one fail and not having completed the rest of the trials yet. Group 4 came in first place with an average of 7 mm from......

Words: 371 - Pages: 2

Premium Essay

Collision of Culture

...Collision of Culture Panama is a country that has had a collision of culture. It was never really a country of its own, but an extension of Columbia. When the idea of connecting the Atlantic and Pacific Ocean together so that the cargo routes can circumvent traveling around South America, is when it became an area of name. First the French tried to create this connection and failed in the 1880’s. Again in the turn of the century the U.S. had an interest in creating this passageway and developed a treaty and proposed it to the Columbian Senate and it was denied, this in turn cause the Panamanians to rebel and the U.S. helped support them. The U.S. helped rebel the Columbian forces and they gained their independence. Although Panama got its independence when the United States backed the revolt from the Columbian senate, it is still a typical Middle American country. It has a population of 3.5 million people, seventy percent of it is mestizo and has its minorities that are made up of Amerindians, whites and blacks. The primary language is Spanish while English is spoken in many parts as well. The population is mostly in the uplands, tierra templada and tierra fria, west of the canal. Here they produce bananas, coffee, sugarcane, and seafood such as shrimp. Panama is also an entrepÔt. They store products here that come in from the Pacific and Atlantic Ocean, and prepare them for transport to South America. This has given the Panamanians infrastructure in the region...

Words: 280 - Pages: 2

Premium Essay

Allegiant Air

...Allegiant Air Portfolio Embry – Riddle Aeronautical University Allegiant Air Portfolio Introduction Allegiant is more than an airline, it’s an innovative travel company dedicated to providing the best travel deals to its customers. Linking small U.S. cities to world-class leisure destinations such as Florida, Las Vegas, Phoenix, California, Hawaii, and Myrtle Beach, S.C. Allegiant provides low-cost travel packages that include not only air, but hotel, rental car and entertainment tickets (Lindsay, 2009). History Allegiant was founded in 1997 in Fresno, California. In 1999, the company began scheduled passenger service between Fresno and Las Vegas utilizing a DC-9 aircraft (AllegiantAirInformation, 2010). In December 2000, Allegiant filed for bankruptcy and Maurice J. Gallagher Jr., the major creditor of the airline, gained control of the business during reorganization (AllegiantAirInformation, 2010). In June 2001, Gallagher restructured the airline to a low cost model and moved the headquarters and operations to Las Vegas, where they remain today. Allegiant’s unique strategy has allowed the company to remain profitable every quarter since 2003 despite industry challenges that include fluctuating fuel costs and an unstable economy. Gallagher remains Chief Executive Officer and Chairman of Allegiant (AllegiantAirInformation, 2010). Today, the travel company continues its focus on linking travelers in small cities, generally at underserved airports that have......

Words: 2922 - Pages: 12

Free Essay

Drama in the Mid Air

...Character building becomes a habit. If we want to build a pleasing personality, we have to examine our habit closely. What begins as an occasional indulgence turns into a permanent flaw. Ask yourself the following questions:- * Do you let the quality of your work detoriate? * Do you indulge in gossip? * Is ego and envy your constant companions? * Is empathy in short supply? * We are creatures of habit. That is good because we have to constantly think before doing anything; we would get never anything done. * If you want to do anything in an urgent manner you can do it accordingly. The matter has been done seriously with references to the matter as discuss with you. You may have the legal things in that matter. If I want to do the things in a day in order to be more effective with them you can easily do the things with them. It was thought in the long run that they will go the places they came from. Activity is not the same as that of accomplishment. Do not confuse motion and progress. A Rocking Horse keeps moving but do not make any progress. A man was out driving withm his wife the wife sajd,’Honey we are going the wrong way,”The husband replied,”Who cares ,we are making a great times, If we confuse activity with accomplishmentwe could be making great time but we would not get anywhere. A farmer had aDogthat used to sit in the roadsidewho used to wait for the Vehicle to come.As soon as one come .he would run down the road.barking and running to......

Words: 568 - Pages: 3

Premium Essay

Air Bag

...The air bag is the second and a more recently developed system that is used to deploying a rapidly inflating cushion in the space between the passenger and the steering wheel or dash board to prevent crash injuries. Fig1-Diagram of an airbag.[3] 2.History of Airbag:- The car manufactures has spent a great time in advancing car safety features. The airbag is one innovative safety feature. Before the airbags that were placed in cars, the cars did not have any safety features. They had an automatic seatbelt. The car manufactures first introduced the airbag system in the 1970s. In 1971 the Ford Company tested the airbag system at an experimental fleet. Then a few years later the Chevrolet made the airbag in cars just for the governmental purposes. Later on General Motors offered the airbags in the cars as an option. By 1988 Chrysler they made it standard on their cars to have an airbag. The car manufactures made an improvement on cars on so they seem. The airbag was placed in the car, which deploy at 200 mph. It was found on the driver side only and then later other places of the car got airbags. This may cause deaths or potential injuries due to some drivers sit very close to the steering wheel. Advancements in the airbag system have made the cars today much safer. Volvo was the first one to introduce the side impact airbag in 1995. Some Car companies produced the knee airbag in 2003 and in 2008 some cars are found with rear airbags. Which caused side impact collision......

Words: 7368 - Pages: 30

Free Essay

Physics Collisions

...By partaking in three unique scenarios of both elastic and inelastic collisions, I was able to conclude that speed and velocity are both conserved. This conclusion was made through the change in velocity of a cart relative to its "crasher". For example: throughout the different-mass elastic collisions, the speed that which the cart started and ended were equivalent - indicating that there was conservation of speed, in addition to the complete transfer of velocity. However, in the different-mass elastic collisions, the transfer of the speed of the cart was not complete, but instead, the lighter cart moved quicker than the heavier cart. This shows us that although force may be the same, the transfer of momentum shows us why the lighter cart moves more quickly than the slower. Throughout our previous unit, we described the constant velocity of objects in motion. That laid the basis for this next unit, where we will be studying why and how the object moves the way it does, specifically the "push" or "pull" of force. The heavier cart in a same-direction elastic collision seems to push the lighter cart, which causes an increase in speed for the lighter cart. Although we may have brushed on the surface of movement, this unit will pave the path for further investigation on velocity as well as momentum. According to today's lab, it is possible to measure the mass of the carts and then multiple the mass by the velocity to determine momentum. These two things will be related to......

Words: 279 - Pages: 2

Premium Essay

Collisions and Conservation of Momentum

... Collisions and Conservation of Momentum Go to and click on Run Now. 1. In the green box on the right side of the screen, select the following settings: 1 dimension, velocity vectors ON, momentum vectors ON, reflecting borders ON, momenta diagram ON, elasticity 0%. Look at the red and green balls on the screen and the vectors that represent their motion. a. Which ball has the greater velocity? The red ball has the greater velocity b. Which has the greater momentum? The green ball has more momentum 2. Explain why the green ball has more momentum but less velocity than the red ball (HINT: what is the definition of momentum?). The green ball has more momentum and less velocity because momentum depends solely on mass and velocity. Momentum = Mass(Velocity) Thus, since the green ball has a greater mass than the red ball, the green ball’s mass times its velocity is more than the red ball’s mass times its velocity. 3. Push “play” and let the balls collide. After they collide and you see the vectors change, click “pause”. Click “rewind” and watch the momenta box during the collision. Watch it more than once if needed by using “play”, “rewind”, and “pause”. Zoom in on the vectors in the momenta box with the control on the right of the box to make it easier to see if necessary. a. What happens to the momentum of the red ball after the collision? The......

Words: 866 - Pages: 4

Premium Essay

Phs 113 Mid Term

...“apparent temperature”. (Do not give three examples of the same type of apparent temperature). For each type, explain why the “how-it-feels” temperature differs from the actual air temperature. 1. Due to the serious effects on your health that weather can have on a person, the Heat Index was developed. The heat index takes into account air temperature and relative humidity to determine the apparent temperature of what it feels like outside. This differs from the actual air temperature as it can feel hotter outside when there is less humidity in the air. 2. How the wind makes us feel can be explained by the wind chill index. When the wind blows, it moves the warm insulating air away from you and heat is rapidly lost. When the wind blows faster, we lose heat even faster which makes us feel cold. This calculation takes into account wind speed at 1.5 meters because that is where the upper body is located and it converts the winds ability to remove heat away from a person’s face into the wind chill equivalent. This is different than the actual air temperature as the wind chill temperature is usually lower because of the lost heat from the wind. 3. The last temperature is the wet bulb temperature. This indicates the lowest temperature that can still evaporate water. The wet bulb temperature is lower than the air temperature, but as the two get closer together it is harder for the skin to evaporate water which may make someone sweaty and harder for them to cool off. 4. I thought I......

Words: 2090 - Pages: 9

Free Essay

Is the Coefficient of Restitution Constant for All Collision Velocities

...Introduction When an object collides with another, momentum is conserved, but kinetic energy is not. This experiment was designed to find if the coefficient of restitution, e, changes for high-velocity collisions. At low velocities colliding objects will tend to maintain their shape, size and elasticity, so e is likely to be constant over a range. However, at high velocities colliding objects may change their physical properties and therefore a change (probably a reduction) in e may be observed. A small reduction in e was observed, but this was probably accounted for by air resistance and not a change in the material. Theory When a collision occurs, total momentum is conserved, but kinetic energy is not. When a ball, for example, bounces off the floor, it loses a little momentum to the Earth so the total momentum of the system is unchanged. Its KE, given by the formula [pic], assuming it was dropped from rest, will reduce and it will bounce to a height lower than its original height, as shown in diagram 1: Diagram 1: ‘H’ is drop height and ‘h’ is bounce height. The coefficient of restitution is the ratio of the difference in the initial speed and the final speed: (i) is the general formula for e, (ii) is when distances are measured on a drop (one object is stationary), and (iii) is when velocities are measured and one of the objects is stationary. Equation (ii) will be used here. Method Apparatus: Rubber ball, camera,......

Words: 687 - Pages: 3

Free Essay

Collision Regulations Part 1

...COLLISION REGULATIONS See First Class Sailing Cockpit Companion and RYA Day Skipper booklet. Steering and Sailing Rules Keep a proper look out. Maintain a safe speed. Determine if a risk of collision exists by taking a bearing of the other vessel. If the bearing doesn’t change after a few minutes you are on a collision course. Determine whether you are the stand on vessel (see below). If you are not the stand on vessel you should take early and ample action to avoid a collision. Ie. A bold alteration of course/speed in good time. BUT….! If the situation develops so that the collision cannot be avoided by the actions of the Give Way vessel alone, the Stand on Vessel must act to avoid collision. Ie. all vessels have a duty to avoid a collision. On the high seas: A power driven vessel gives way to a sailing vessel. Both a power driven vessel and a sailing vessel give way to a fishing vessel. All three of these gives way to vessels Restricted in Ability to Manoeuvre, vessels Not Under Command and vessels Constrained by their draft. In other cases: In a TSS a sailing vessel or a vessel under 20m LOA shall not impede a power driven vessel using the TSS - Rule 10. In a narrow channel a sailing vessel or a vessel under 20m LOA shall not impede a vessel that has to navigate within the narrow channel – Rule 9. A vessel, regardless of it’s type, when overtaking another vessel shall keep well clear. Sailing Vessels (Rule 12) A yacht on port tack gives way to a yacht on starboard......

Words: 403 - Pages: 2

Free Essay

Air Masses

...extent is the climate of the British Isles a product of the air masses that affect it? (40 marks) The UK experiences a temperate, maritime climate which is subject to change on a day to day basis throughout the year, therefore making it extremely difficult to predict the weather for up to more than just a couple of days ahead. This variable climate is so apparent due to the geographical positioning of the UK in relation to the Earth in terms of the fact that it is situated just off the edge of continental Europe and yet is surrounded by sea. These locational characteristics mean that the UK is subject to weather determined by five major air masses travelling from all different directions over both the sea, and the land. Air masses are bodies of air which pick up the characteristics of the area that they have come from in terms of the temperature, moisture content and pressure. The air masses which play the biggest role in determining the weather in the UK are the Polar and Tropical maritime air masses. These come to the UK from over the Atlantic Ocean and are thought to influence up to 80% of the weather that we receive. The first of these is the Tropical continental air mass which travels over the Atlantic Ocean from the south west of the UK. During the winter, when we are affected by this particular air mass, we can expect conditions to be relatively mild and often rainy. This is due to the fact that this maritime air mass travels to the UK over sea therefore......

Words: 1286 - Pages: 6

Premium Essay

Air Controller Discipline Probed by U.S. in Near Plane Crash

...Title: Air Controller Discipline Probed by U.S. in Near Plane Crash Abstract: This article takes a look into the disciplinary problems at U.S. air traffic facilities. Summary: The author discusses the struggle of the Federal Aviation Administration’s efforts to reprimand air traffic controllers. About forty percent of the controllers who have come under scrutiny for their poor judgment and lackadaisical performance of their job which have resulted in tragedy and/or near mishaps were allowed early retirement or have kept their jobs. With the help of their union contract or the Merit Systems Protection Board for federal employees which was established to protect federal employees against abuses by agency management. The latest to show problems was in June 2011. An air controller near Gulfport Mississippi, who had been repeatedly disciplined, was the subject of a government safety investigation. The controller instructed two planes to take off toward each other into a near mid air collision. Another incident in which the air traffic controller was in line for termination occurred in 2009 at Teterboro Airport in New Jersey, in which, a controller was blamed in part for a fatal mid-air collision because the controller was joking with an airport employee about barbecuing a dead cat while on duty. The FAA was also thwarted in attempts to fire a controller at JFK International for allowing his kids to make radio calls to aircraft. After the incident in Mississippi, the FAA......

Words: 381 - Pages: 2