Automatic Flight Control Systems Engineering Essay

Automatic Flight Control Systems Engineering Essay We live in a world where technology is, if not being improved, developed by the second. Everyday new improvements, inventions and discoveries are made. One industry that is always on the lead when it comes to new inventions and innovations is the Aviation Industry. Over the years, aircrafts have been facing major improvements on the structure, fuel efficiency, life-span, range of flight. But one of the best improvements that have been done on every aircraft (commercial) that had the biggest impact in the Aviation Industry and most probably the main reason why the industry has been booming up is the improvements done in the Avionics section, specifically the Automatic Flight Controls. In the beginning, Pilots were trained to fly the aircrafts alone. But after several years, it is now the pilots programming the computer, telling it where to fly, at what altitude, etc. This computer is the AFCS (Automatic Flight Control System). In todays modern world of flying, it is the AFCS who is technically flying the aircraft, from cruising to landing, and for some until parking. The AFCS has a lot of advantages when compared to human pilots when it comes to flying. Here are some of them: The AFCS has the ability to overcome deficiencies when it comes to stability and control. The AFCS improved the handling qualities. Such as, when the airspeed or the altitude of the aircraft needs to be constant. The AFCS is more accurate and hence is able to carry out several tasks that the pilot is not able to do. * Source: Emirates Aviation Colleges Automatic Flight Control Systems Book (Chapter 3.1.3) To get a better understanding of the AFCS, the different parts of it will be discussed, such as the Autopilot System, Flight Director System, Auto Throttle System and etc. The information about the AFCS will be based on one of Boeings classic aircrafts, the 737-500. FLIGHT MANAGEMENT SYSTEM (FMS) The Flight Management System is navigation, combined flight control, a Built-In Test Equipment (BITE) and a guidance system. The FMS provides control and operation of five independent subsystems to provide lateral navigation (LNAV) and vertical navigation (VNAV) for performance management and optimum flight profiles. The Flight Management System is not labeled to any control panel or any single component as it is an integration of five independent subsystems. These subsystems are: Digital Flight Control System (DFCS) Inertial Reference System (IRS) Autothrottle Electronic Flight Instrument System (EFIS) Flight Management Computer System (FMCS) * Source: United Airlines Boeing 737-322/522 (page 6, Chapter 22-2, Oct 99) from Emirates Aviation College Library This system was designed to increase fuel efficiency, safety and decrease workload. For both pilots, this means that they can select full FMS operation or Autopilot Flight Director System (AFDS) for a complete automatic flight. They can even use the Control Display Units (CDU) to provide, for manual flight, reference information. Management and operation is totally under the control of the flight crew. There are only certain operations that can only be implemented by the flight crew. They are: landing rollout steering, thrust reversal, speed brake operation, altitude selection, landing gear and flap operation, instrument landing system (ILS) tuning, thrust initiation, brake release, airplane rotation and steering during takeoff roll. * Source: United Airlines Boeing 737-322/522 (page 6, Chapter 22-2, Oct 99) from Emirates Aviation College Library FMS BUILT-IN TEST EQUIPMENT (BITE) Ground test capabilities and self-contained in-flight monitoring are provided for the FMS subsystems. The flight management computer (FMC) coordinates the BITE testing of the five subsystems and must be functional for access to any subsystems built-in test equipment. BITE for the FMS subsystems is accessed from both CDUs located in the cockpit. Each FMS subsystems run its own systems test. Included in the tests are for its computers, sensor inputs and several interfaces. Any fault findings during flight are automatically stored for analysis on the ground which is accessed through the bite system. * Source: United Airlines Boeing 737-322/522 (page 8, Chapter 22-4, Oct 99) from Emirates Aviation College Library THE BOEING 737-500 CATEGORY *3 General AFCS Category Capability Chart *4 Boeing 737-500 AFCS Category Capability Chart The Boeing 737-500, according to the diagram is in Category 3B. In order for this aircraft to operate at Cat3B weather minimums, the equipment that must be available in Cat2 should be functional. These equipment are: Both Flight Directors One Autopilot in CMD Both Air Data Systems (ADS) Both windshield wipers Two generators Both EFIS systems displaying: Radio Altitude Glideslope and Localizer Deviation Attitude Autopilot Status Engaged Pitch and Roll Modes Decision Height Both Radio Altimeter Systems Both ILS Marker Beacon Both IRS Now for the aircraft to operate in Cat3B all the equipment listed for Cat2 must be fully operational, provided that the equipment as follows is included: The Autothrottle Both Autopilots Both Hydraulic Systems * Source: United Airlines Boeing 737-322/522 (page 12, Chapter 22-8, Oct 99) from Emirates Aviation College Library AUTOMATIC FLIGHT CONTROL SYSTEM (AFCS) The AFCS or also known as Auto Flight System (AFS) comprises of three independent systems. They are: A Yaw Damper System A dual Digital Flight Control System (DFCS) An Autothrottle (AT) System These 3 systems provide automatic aircraft stabilization about the roll, pitch and yaw axis. The AT and the DFCS systems control the aircraft with the selected Mode Control Panel (MCP) guidance from N1, heading, radio, IRS, FMC and ADC inputs. * Source: United Airlines Boeing 737-322/522 (page 10, Chapter 22-6, Oct 99) from Emirates Aviation College Library YAW-DAMPER SYSTEM The Yaw Damper System is composed of various components, such as: Yaw Damper Engage switch Warning Annunciator Yaw Damper Coupler Integrated Flight System Accessory Unit (IFSAU) Yaw Damper Engage solenoid Position Transducer and Transfer Valve on the rudder Power Control Unit (PCU) Yaw Damper position Indicator * Source: United Airlines Boeing 737-322/522 (page 12, Chapter 22-8, Oct 99) from Emirates Aviation College Library The Yaw Damper System smoothens the flow of air that causes the aircraft to yaw and thus causes it to Dutch Roll. The Dutch Roll is a phenomenon that occurs when a sidewind hits the aircraft which causes it to yaw. This yawing motion exposes one side of the wing to the wind more than the other side. The exposed side of the wing, gains more speed and more speed generates more lift on that particular side. The lift that was generated on the exposed side of the wing causes the aircraft to roll. Hence, the term Dutch Roll. The Yaw Damper System is a stability augmentation system that works full time, providing yaw axis damping for the complete flight, including both takeoff and landing. It is connected in series so that none of the rudder feedback is applied to the pedals. This now allows the Yaw Damper System to operate in an independent manner without interfering the initiated rudder commands by the flight crew. Both the yaw rate and the yaw direction are detected using a rate sensor located in a Yaw Damper Coupler. The rate sensor of the Yaw Damper is sensitive that the rudder is displaced at a proper time to dampen out any sidewinds hitting the aircraft before it can obviously affect the flight path of the aircraft. * Source: United Airlines Boeing 737-322/522 (page 12, Chapter 22-8, Oct 99) from Emirates Aviation College Library The Yaw Damper authority is only  ±3 ° deflection of the rudder. Its actuator gets no turning commands from the longitudinal axis AP. The Boeing 737-500 does not have a 3-axis AP. It only has 2 which is the pitch and roll axes only. In this aircraft, turn coordination is not available. A roll command which sends a cross feed signal in proportion to the bank angle due to aircraft banking, is sent to the Yaw Damper to prevent undesirable opposition to roll attitude. * Source: United Airlines Boeing 737-322/522 (page 12, Chapter 22-8, Oct 99) from Emirates Aviation College Library *5 Yaw Damper System Diagram Yaw Damper Operation The Yaw Damper is confined to 3 modes of operation. These modes are: synchronization mode, engaged mode interlocks and logic and engaged mode operation. Before the yaw axis engagement, the Yaw Damper coupler is in the synchronization mode for 2 seconds. The synchronization mode provides a null output to the electro-hydraulic transfer valve to prevent a sudden change in the Yaw Damper coupler. The mode is accomplished by returning the controlled signal back to the output amplifier. The output of the valve amplifier is reduced to null as the output of the integrator increases, causing the signal to be cancelled. Prior to the engagement of the Yaw Damper its actuator remains at the center which nulls the position feedback to the Yaw Dampers coupler. * Source: United Airlines Boeing 737-322/522 (page 14, Chapter 22-10, Oct 99) from Emirates Aviation College Library The system is activated by placing the Yaw Damper switch on the flight control module to ON. Both Bs of the flight control switch and system hydraulic power must be ON and available, respectively, in order to power the Yaw Damper actuator portion of the PCU. 2 seconds after the Yaw Damper is on, the YAW DAMPER light extinguishes. The Integrated Flight Systems Accessory Unit (IFSAU) contains the logic to engage the system, monitor the engagement and illuminate the amber-colored Yaw Damper disengaged annunciator light. If, for over 2 seconds, the AC power is lost, the YAW DAMPER light illuminates and the Yaw Damper switch returns to OFF position. The Yaw rate gyroscope which is located inside the Yaw Damper coupler senses the movements by the yaw axis. The coupler only responds to yaw movements that produce the Dutch Roll. Before the command signals are applied to the transfer valve which is located inside the Yaw Damper actuator, it is first filtered and amplified. The transfer valve then sends hydraulic pressure in order to deflect the rudder and reduce the aircrafts oscillation by the yaw axis. The output of the Yaw Damper actuator is summed with the rudder pedal manual input in order to move the main rudder Power Control Unit (PCU) that controls the rudder. Now as the actuator moves the linear variable displacement tranducer (LVDT) supplies the signal of the position feedback to nullify the signal coming from the yaw rate gyroscope. When the movement (by the yaw axis) stops, the feedback signal returns the rudder to the original position.

Factors that Relate to Student Persistence in a Two-Year Vocational Program at a Community College Essay

Student persistence is one of the many factors that educators try to consider in the goal making students succeed in their education. Schools cater to the academic needs of students and it is the primary role of schools to provide education to children, but nowadays there have been a number of children that have low interest in finishing an education (Smith, 2002). Community colleges are institutions that cater to those children who want to consider taking up a vocational course instead of a bachelor’s degree after graduating from high school. In institutions such as these, there have been a number of studies that shows that students enrolled in this program identified different factors that contribute to their success in the program. The references gathered in this study revealed seven thematic findings with regard to persistence of students enrolled in a community college. These first thematic finding that studies reveal relevant to the success of student enrolled in community colleges is support, this support comes from peers, family members and as well as support from mentors. The second thematic finding is financial support, wherein students saw that being able to be granting a support financially to cater to their education were beneficial for them to continue education. The third thematic findings discusses the different self-variables that contribute to their success, these factors include the determination of a child to succeed and the fear of failing as one of the important factors that made them continue schooling. The fourth thematic finding will discuss all about a student’s background or life experiences that contribute to their persistence in school. The fifth will tackle all about how different techniques that students use in coping with school are beneficial to their stay at school. The sixth will look into how students say that behaving in a professionally during their stay at school became beneficial for their success at school. The seventh and the last will dwell into the different challenges that students face in school, such as stress, as a major barrier in their success at school. All of these will be given corresponding analysis, discussion and interpretation as regard to their contribution to the success of students enrolled in community colleges. Thematic Finding 1: Support It has been well known that one of the factors that contribute to student success is the support which students get from educators as well as from their peers. Studies reveal that all participants believed that the support that they have received from mentors, peers and family members played a big role towards their success in school. Support from people surrounding a student is notably a factor to consider in ensuring success of a child at school. The first support that would surely boost student confidence in continuing their education comes from their own mentors. This is said to be true because if mentors or educators are providing support to their students, they would be able to have a sense of encouragement, and this encouragement boosts their determination and therefore makes the student persist school (Hu & Ma, 2010). This kind of mentor-student support is viewed as a counseling support, wherein this kind of support is seen to be beneficial for student to persist school (Fralick, n.d). This type of support has been supported by mentors or educators as beneficial for student’s persistence in school. Aside from support that student’s get from educators it is also seen that peer support plays a big role in the persistence of students at school. The role that the peers of an individual play a big role is seen not only in the education of an individual but as well as in their own lives. This is why studies have shown how beneficial peer support plays in assisting a student not only in academics as well as personal matters (Quimbita, 1991). Peer support is also seen as a major factor that contribute to the persistence of a child at school because of the fact that students get to share the learning experience with their peers in other words, they experience shared learning (Holzer & Nightingale, 2009). It is here that peer support is indeed a major factor that would contribute to the persistence of a learner. Aside from mentors and peers, the one and most special source of support would come from family members. Different studies have revealed that the support coming from parents and other family members have been beneficial for student success (Holzer & Nightingale, 2009). It is in this kind of support that students would see that the people play a big part in their lives are supporting them, this kind of support provides encouragement, and this is what students take in order for them to succeed in school. The support that learners gain from these different types of groups evidently brings out one thing that is so important in one’s success at school, and that is encouragement that brings about determination. In analyzing the role of support in student persistence at school, it could be clearly seen that the one factor that students get from these support is encouragement. This encouragement from supports such as educators, peers and family members makes students determined to succeed academically because they know that people believe in them, this alone is big factor to consider in ensuring student persistence at school. Comments: Thematic Finding 2: Financial Support It is common that students that finish high school would not continue on going to universities and colleges, the primary reason for this is mainly on financial issues. This has been an issue especially among students that belong to poor families (Smith, 2002). Seeing financial issue as a barrier for children to acquire an education, different financial support is now granted to learners in order for them to acquire an education (Wan Ko, 2005). Different studies have revealed that majority of the total population of the participants saw financial aid or assistance as one factor that contributed to their success at school. Financial support or aid is said to be beneficial to student’s persistence at school because of the financial support it gives to cater to the different need of the students in the duration of their stay in the school (Wright, 2010). The various financial aids available primarily cater to the financial needs of individuals during their whole stay at school; this is especially beneficial for students that belong to poor families (Hu, 2001). Educators who avail such assistance are provided full financial support, from enrollment to different school related finances, they are provided with all of these things (Wright, 2010). Especially among students that belong to poor families, this kind of support is something that would really help them in their pursuit of obtaining an education (Scrivener, 2008). Financial support is evidently a need amongst students, because of the fact that as years pass, the price of education n also increases and the less fortunate are deprived of an education because of this (Li, et.al, 2008). Such financial support is evidently needed in community colleges, because of the fact that most of the population of students enrolled in community colleges belongs to financially challenged families (Wright, 2010). Some financial aid or services not only provides financial assistance, most services also provide rewards for academically high performing students (Holzer & Nightingale, 2009). The additional perk from financial support makes students motivated to perform well academically (Holzer & Nightingale, 2009). Such rewards are not only provided for financial sake alone, this kind of reward also provides learners with an opportunity to perform well academically (Holzer & Nightingale, 2009). This shows that such financial assistance would not only provide the student with the chance to have an education, but as well as provide motivation to perform well in class. This kind of motivation brought about by financial support allows students to improve their grades, as well as provide enough motivation to bring about a sense of persistence in school. Studies and reports have revealed that indeed financial support plays a big role in student persistence in school. Financial support is seen to be one primary factor in student persistence in school because of how this service caters to the needs of students who are financially troubled and at the same time this service provides learners with an opportunity to do better at school and provide enough motivation for students to persist school

Automobile Industry History Essay

You are here: Home †º World Industries †º Auto Industry †º Auto Industry | Automobile Industry | Car Industry Auto Industry | Automobile Industry | Car Industry. Automobile Industry History : In the year 1769, a French engineer by the name of Nicolas J. Cugnot invented the first automobile to run on roads. This automobile, in fact, was a self-powered, three-wheeled, military tractor that made the use of a steam engine. The range of the automobile, however, was very brief and at the most, it could only run at a stretch for fifteen minutes. In addition, these automobiles were not fit for the roads as the steam engines made them very heavy and large, and required ample starting time. Oliver Evans was the first to design a steam engine driven automobile in the U.S. A Scotsman, Robert Anderson, was the first to invent an electric carriage between 1832 and 1839. However, Thomas Davenport of the U.S.A. and Scotsman Robert Davidson were amongst the first to invent more applicable automobiles, making use of non-rechargeable electric batteries in 1842. Development of roads made travelling comfortable and as a result, the short ranged, electric battery driven automobiles were no more the best option for travelling over longer distances. The Automobile Industry finally came of age with Henry Ford in 1914 for the bulk production of cars. This lead to the development of the industry and it first begun in the assembly lines of his car factory. The several methods adopted by Ford, made the new invention (that is, the car) popular amongst the rich as well as the masses. According the History of Automobile Industry US, dominated the automobile markets around the globe with no notable competitors. However, after the end of the Second World War in 1945, the Automobile Industry of other technologically advanced nations such as Japan and certain European nations gained momentum and within a very short period, beginning in the early 1980s, the U.S Automobile Industry was flooded with foreign automobile companies, especially those of Japan and Germany. The current trends of the Global Automobile Industry reveal that in the developed countries the Automobile Industries are stagnating as a result of the drooping car markets, whereas the Automobile Industry in the developing nations, such as, India and Brazil, have been consistently registering higher growth rates every passing year for their flourishing domestic automobile markets. Those who are interested in gathering more information about the Automobile Industry, may browse through the following links :

1. What Are the Strengths and Weaknesses of the Hilton...

CRITERIA OF CHOICE FOR PROCUREMENT METHODS Prof. Peter Hibberd Dr Ramdane Djebarni Centre For Research In The Built Environment University Of Glamorgan, Pontypridd, Mid Glamorgan CF37 1DL, UK 1. Introduction Over the past fifteen years much work has been done on attempting to define procurement paths and Masterman (1992) provides a good background to some of this work. As the traditional procurement route came under closer scrutiny other procurement routes developed and consequently means for selection were considered. In 1985 NEDO set out general requirements for the selection of a procurement path and others including Skitmore and Marsden in 1988, Bennett and Grice in 1990 and ELSIE computer system in 1990 sought to assist in†¦show more content†¦Respondents were also given the opportunity to add any further variables that they may see as important in their choice. 3. Methodology A questionnaire was prepared with the objective of obtaining information relating to procurement choice and satisfaction with procurement methods used, among other things. A total of 122 questionnaires were mailed to both clients and consultants of which 64 responses were received, which is a good answer rate (52%). The data was analysed statistically using SPSS for windows. 4. 4.1 Results Procurement Selection Criteria Respondents were asked to indicate on a scale from one to ten what they believe to be the degree of importance of procurement selection criteria mentioned earlier in this paper. The results depicted graphically in figure 1 shows the distribution of their answers. In order to find out how significant are these results statistically, χ2 test was conducted and its results are presented in table 2. Selection Criteria χ2 Accountability 52.34 Design input 06.78 Dissatisfaction with previous procurement 09.78 process Knowledge of process 15.50 4