B737 Ng Flight Control System Engineering Essay

B737 Ng Flight t altogethery System Engineering EssayIn this chapter the differences of the Air good deal A320 and Boeing 737 NG leave behind be discussed. There will be looked at the flight contain transcription of the Boeing 737 NG and the flight envision strategy of the Airbus A320 (2.2) after(prenominal) that a comparability surrounded by the conventional frame and fly-by-wire system (2.3).2.1 B737 NG flight chair systemThis section will discuss the flight meets of the Boeing 737 NG. At primary the primary flight restraints especially the ailerons (2.1.1) and also the thirdhand flight governs of the Boeing 737 NG trailing edge devices (2.1.2) will be discussed.2.1.1 Primary flight controlsIn this subsection, the primary flight controls of the Boeing 737NG will be discussed. The ailerons will be investigated as primary flight control in this chapter. The com amaze of the system (2.1.2a), the stimulant drug of the system (2.1.2b), the transportation of emblems (2.1 .2c), the output signals (2.1.2d) and the hydraulic system of the Boeing 737NG will be discussed (2.1.2e)2.1.1a Com coiffureThe aileron system exist of two ailerons. The Boeing 737 has an aileron on each wing. They argon placed on the outermost berth of the wing to frame a greater moment over the carpenters planes longitudinal axis. Over this axis the airplane will be able to roll. Because the ailerons ar mount on the outer side of the wing the needed powerfulnesss can be lower than when they are placed on the inner side of the wing. The moment of the aileron is the force cipher by the arm length.2.1.1b InputThe ailerons are positi aced by the control bicycles of the airplane operates. When the pilot controls his steering cycles/second a mechanical cardanic movement will determine the comment signal transferred to the transfer mechanism.The transferm mechanism keep the control wheel movement to a limitof 107.5 degrees left and right. This mechanism is mounted chthoni c the steering column of the pilot. The roll axis force transducer is mounted surrounded by the control shaft and aileron ticktack below the captains control column. The force transducer provides duple electrically isolated ac output signals that are proportional to the force applied to the control wheel or column. The signals are used by the autopilot computers when the system is engaged in CWS (manual of arms) mode or in CMD mode with no flight mode selected. Both control wheels are telegraph mounted connected to each other, when the captain steer his control wheel the left aileron control bus drum will rise and operated the control cable to rotate the right aileron control bus drum. This drum is connected exactly as the captains control wheel and the first officers control wheel will move.CUsersTemminckDropboxHvA Projectgroep 1VProjectWerkmapKeespage 27-4.jpg2.1.1c TransportBy rotating the control bus drum, the control drum also will rotate. The control cable will be opera ted and will run done the airplane and routed by cable guides and kept on tension with cable tensioners. In the main wheel well the cable will be attached to the aileron luggage compartment quadrant. On the quadrant the new outgoing cable is mounted. The quadrant is mounted on two aileron power control units (PCU). This PCUs are mounted at the aileron control quadrant. On this quadrant the aileron gossip shaft is mounted. On this shaft the autopilot control rod, the PCUs four pogo input cranks, the feel and centering unit and the aileron actuator are mounted.For backup two PCUs are mounted to help the pilot to create a higher force to the ailerons so the pilot dont need all his strength to control the ailerons. Also there are four pogo inputs installed between the body quadrant and the input shaft. These are to control the movement of the cables so that they are on tension at all times and not move when the dont need to. The feel and centering unit is used to position the ailer ons to his neutral position. This can be done by movement of two aileron trim switches on the aft electronic panel. The aileron trim actuator can position the aileron input shaft to trim the system. The total trim the pilot defy made can be read on the aileron trim indicator on the control wheel. The autopilot aileron actuator is duplicated for safety reasons. The autopilot actuator is with the autopilot input rod mounted to the aileron input shaft. This actuator will be electronic controlled by the flight control computers. All the actuators are hydraulic controlled by system A and B.CUsersTemminckDropboxHvA Projectgroep 1VProjectWerkmapKeespage 27-7.jpg2.1.1d OutputThe control cables will led done the wings until they reach the aileron wing quadrant. This quadrant is kept on tension by the aileron cable tension spring. This for that the trenched out cables are kept on tension. The quadrant is connected with and pushrod connection to the aileron. On the aileron an aileron equi librize tab is mounted and connected with control rods. The aileron is armed with four balance panels to keep the balance in the ailerons. And this panels are equipped with fixed balance weights. The output signal of this system is that the aileron will move up or d give after movement that the pilot will make by moving the control wheel.CUsersTemminckDropboxHvA Projectgroep 1VProjectWerkmapKeespage 27-6.jpg2.1.1e Hydraulic systemThe ailerons are powered by system A and B. When both of this systems fails, the aileron can still be operated manually by controlling the cables. The left aileron is powerd by system a and the right aileron is powered by system b.During normal operation of the ailerons, an aileron input goes done the input pogos of each PCU to its input crank. The upper and lower input cranks move, slides in the control valve, and supply hydraulic pressure to the actuator. The lower input crank is connected to the primary slide and the upper input crank is connected to t he unessential slide. A torsion spring inside the PCU connects the two input cranks. relocation of the primary slide supplies one-half the total flow rate, and movement of the standby slide supplies the other half. The primary slide moves to its full effective touch before the secondary crank starts to move the secondary slide. When the primary and secondary slides move, hydraulic pressure goes through the control valve to one side of the actuator. This moves the actuator accommodate and the respective aileron body quadrant to the commanded position. The other side of the actuator is connected to the return.If one PCU cant supply a hydraulic pressure, its bypass valve will be activated and moves to the bypass position. This connects the two sides of the actuator, and prevents a hydraulic lock condition. When the pilot moves the control wheel, the ON side PCU still moves to his commanded position normally. As the ON side PCU moves, it also moves his respective aileron body quadr ant and back drives the strike side PCU actuator housing. When the OFF side housing moves, hydraulic fluid is pushed through the bypass valve. If one PCU input pogo cant move freely, the pilot must(prenominal) supply approximately 20 pounds of additional force to compress or extend the spring inside the pogo. The other PCU input pogo still moves its own input crank and slide to the commanded position. This equalizes pressure on both sides of the actuator and prevents a hydraulic lock condition. Now the other PCU can move the aileron body quadrant fable normally. As the ON side PCU moves its respective aileron body quadrant it also back drives the OFF side PCU actuator housing. When the OFF side housing moves, hydraulic fluid is pushed through the bypass valve.During a manual reversion, the bypass valve receives no hydraulic pressure and moves to the bypass position. This connects the two sides of the actuator and prevents a hydraulic lock condition. When the pilot moves the contr ol wheel more than threesome degrees, the primary and secondary input cranks hit the mechanical stops on the outside of the actuator housing. As the housing moves, hydraulic fluid in the actuator is through the bypass valve. Movement of the housing also moves the aileron body quadrant assembly to the commanded position.