Commercial Aircraft Systems - Assignment Example

 Task 1 Question 1: Commercial Air Transport (CAT) aircraft make use of instruments to assist navigation in various ways. a) A typical CAT aircraft navigation instrument display and principle of operation, relating this to any ground-based components. Most typical Commercial Air Transport (CAT) aircraft are designed with instrument panels that are similar. This provides consistency for the pilots to enable them switch from one aircraft to another. These instruments are often classified basing on their functions. This include navigation, system instruments and flight. Navigation instruments include direction and electronic guidance. Generally, in CAT aircrafts, navigation instruments are often positioned to the right of the aircraft’s flight instruments. Most current CAT aircrafts are fitted with global positioning systems (GPS) besides navigation instruments that had been in use for many years. One or two instruments called Very high-frequency omnidirectional range (VOR’s) are installed to the right side of the altimeter. The VOR’s has one or two needles and resembles a compass. These needles are used to track ground stations that the pilot selects. The pilot uses them to follow the courses by ensuring he keeps the needles centred in order to stay on course. Other instruments include the Horizontal situation indicator (HIS) which is used in incorporating a number of navigation instruments displayed in a single display, and the automatic direction finder (ADF) which also resembles a compass with a large arrow at the centre. b) Differences between the ground and flight components of the instrument. CAT Aircrafts flight system consists of flight displays, engine display systems, multifunctional systems, and crew alerting systems. Ground components have microwave landing systems or instrumental landing systems. The microwave landing systems (MLS) consist of ground equipment, which are divided into the rangefinder components, onboard hardware, and protractor components. Information concerning the angle of descent, approach course, and the course of unsuccessful approach and obtained using an onboad antenna. The DME rangefinder is used to determine the distance. The microwave landing systems also sends using the time-division and phase modulation, the multiplexing additional information. The ground equipment has basic configuration of the AZ (Azimuth Trannsmitter) with the added DME/P rangefinder. On the other hand, the flight components of the aircraft's navigational instruments, are used by flight engineers to detect engine malfunctions, which may affect flight. It also assists a pilot in locating airports and beams and provide alerts to crew members. Besides, the components ensures an aircraft relays and get information from ground sensors. Furthermore, flight components of CAT navigational instrument consist of display monitors, data processors and control panels for pilots (Jabbal, & Crowther, 2010). c) Three of the navigation instruments displayed by CAT aircraft. The three navigation instruments displayed by CAT aircraft are the Magnetic Compass, the Automatic Direction Finder (ADF), and the Ground radar. Question 2: CAT aircraft make use of weather radar a) The requirement for weather radar in a CAT environment. A radar is an important device in the CAT aircraft. It plays a key role in the navigation of the aircraft. Generally, an aircraft radar promotes safe flight even under bad weather conditions. Weather Radar is one of the most active devices in an aircraft. It sends out radio waves while listening for their return. Water has good reflective properties. This property is explored in weather radar such that the storm clouds (clouds that are moisture laden) return a strong echo. The stronger this echo becomes, the higher the moisture production and the higher the violent the storm. Most modern radar can potentially detect Doppler shift. This makes detect water droplets, as well as wind shear. Weather Radar is an active device that sends out radio waves, and listens for the return. It turns out that water is a good reflector, so clouds that are moisture laden (storm clouds) return a strong echo. The stronger the echo, the more moisture, and usually the more violent the storm. b) Weather radar display, relating relevant characteristics of the display (eg range, colours etc.) to the flight path of the aircraft and atmospheric conditions. Weather radar calibration system having reflectors are more often than not located at an adjacent known position to the runway of an airport. The reflectors are shaped in such a way as to direct reflective patterns of a known radar cross-section. This is in response to the radar signals that are transmitted by the aircraft that is meant to follow a known path to the airport. Radar of the aircraft detects the reflector’s radar return signals. The reflectors are designed in a manner that they can effectively minimize multipath reflections away from the ground. This way, it prevents these reflections from disturbing the aircraft reflective properties as it follows the guidance path. A weather radar beam increasingly spreads out when moving away from a radar station. These radar signals send by the weather radar are in the form of microwave radiations and are in the order of a microsecond. As the signal spreads, it covers an increasing large volume. Therefore, the air volume that the radar pulse traverses is smaller for areas that are nearby and larger for far away areas. It decreases resolutions for far distances. Towards the end of a sounding range of 150 to 200km, volume of air that a single pulse scans may be of the order of one cubic kilometer. Because of Rayleigh scattering, part of each pulse’s energy bounces off the small particles to the radar station direction. The volume of air taken up at a point can be approximated using the formula Sending radar pulses Question 3: In CAT aircraft there are differences between typical passenger, flight and cabin crew oxygen systems. a) Differences with reference to roles, responsibilities and needs. An oxygen system is important in CAT aircraft. It provides oxygen to passengers and crew in a flight. Figure 1 shows a aircraft standard oxygen system. Generally, the oxygen demand of the passengers and flight and cabin crew are different. This difference is often controlled by variations in the design of oxygen masks of the flight and cabin crew and passenger. In case a depressurization occurs, a flight and cabin crew must receive sufficient oxygen in order for them to perform well their flight duties. In this case, the flight and cabin crew oxygen demands are greater than the passenger. The flight crew’s oxygen masks have two modes of operation: full demand and diluter demand. For the diluter demand, there is a reduction of oxygen that flows to the mask. This oxygen is fundamentally used in supplementing the cabin existing air. This way, the air that a flight crewmember breathes, is a combination of oxygen flow from a bottle and the cabin air. Diluter demand mode helps to conveniently minimize the flow of oxygen whenever oxygen demands are not great. It is used whenever a flight crew needs to have oxygen mask of above a given altitude or in cases where one of the flight crew member is not in the flight compartment. In cases where a cabin depressurization occurs, the crew needs to use the full demand mode. In this mode, the flight crew receives a 100 percent oxygen, which enables him to perform his duties up-to the cabin altitude within a 40,000 feet range. When a flight crew mask is in this mode, on inhalation, a crew can inhale full oxygen now that his lungs are expanded. During breathing out in demand mode or diluter demand mode, there is a valve in the crew mask that opens to let the air that is exhaled out of the crew mask. In this respect, this valve works as check valve given that flow goes in only one direction. The figure 3 below shows a typical crew mask. Figure 2: Crew oxygen mask Two types of passenger oxygen systems. b) Two Types of Passenger Oxygen Systems. In a CAT aircraft, passengers are provided with oxygen in two ways: gaseous manifold system and chemical oxygen generator. In a chemical oxygen generator system, oxygen is supplied to all other masks within the compartment whenever one mask is pulled. In chemical oxygen system, the operation is based on the chemical reaction occurring between sodium chlorate and iron powder. On the other hand, in gaseous manifold system, all the masks are connected to a central oxygen supply. The oxygen in this system is sourced from the cargo area. Besides, the resetting can only be done in the cockpit. c) Differences between CAT aircraft and single or dual seat military aircraft crew oxygen provision. Two seat military planes travel at very high altitude and have ejection seats (Lovelace, 2012). Therefore, air is pressurized by the engines to ensure that passengers have adequate oxygen a process at times referred to as air bleed. Question 4: CAT aircraft are designed and certified to operate within a range of climactic conditions. a.) Standard reference parameters for atmospheric conditions? The altimeter is an instrument that is used to measure air pressure. For an aircraft, altitude refers to the use of an altimeter to measure air pressure. b.) Conditions that can lead to ice formation on an aircraft on the ground and in flight, how it may be detected and the possible consequences in these cases. Generally, there are two conditions that may lead to ice formation on an aircraft while on flight or ground. Ice may form on the aircraft’s wings or on other parts of the aircraft. These ice accumulation has some impact on the aircraft. First, it causes a decrease in lift as it causes a loss of streamline air flow of the aircraft. Secondly, it can cause a decrease in propeller efficiency due to a change in the shape of an aircraft’s shape, and can potentially damage the aircraft’s fuselage. Thirdly, ice accumulation may cause an increase in drag for similar reason that causes the loss in a lift. It may as well lead to the loss of control. This way, it can restrict or prevent movement of a control surface. This, therefore, means that there is need for the air crew to detect such conditions. CAT aircraft have installed ice detectors on the aircraft wings of to help detect ice formation. This device is in the form of a transducer able to relay information to the pilot for further action. There are mechanisms put in place to prevent ice formation on an aircraft. Every CAT aircraft are fitted with ice protection system, which protects the engine, wings and other parts from any in-flight airframe icing. Some mechanisms employed to reduce ice accumulation include fitting ice electrical heating systems. These heating systems, heat important engines on an aircraft to help prevent formation of ice. Besides a CAT aircraft has a weeping wings that have many holes. These holes release anti icing fluid. The edge of the wings and tail of a CAT aircraft facilitates the heating of air that evaporates ice on contact process called bleed air. There are other precautions including avoiding icing conditions through mechanical means, putting the aircraft of heating hangar, and applying de-icing fluid (Marwedel & Jörg, 2011). c.) CAT aircraft airframe anti-icing system in the cruise or descent. In the descent or cruise, preventive activation must take place before an aircraft enters a risk zone. Minimum rpm levels should be respected in descent. At TAT less than 10 degrees Celsius, the anti-icing system must be activated. Anti-icing system must be activated under slightest risks of icing. This provides for special cases such as sharp drops in temperature and temperature inversion. Equipment that are designed to prevent icing or remove icing come in two flavours: deicing and anti-icing. The-anti-icing equipment is often turned on before the aircraft enters icing condition. It is basically designed to help prevent the formation of ice. On the other hand, deicing equipment are designed is a way that they can remove any ice after it starts to accumulate on an airframe. Lexible rubber-like boosts with the ability to contract and expands in ice-prone regions are among the common types of deicing equipment is use. The liquid freeze point depressant systems for instance a weeping wing system, TKS, which characteristically disperse off low freeze point liquid for portions of an aircraft are also anti-icing. This however, depends on the activation of the fluid dispersing system. d.) . Precautions to be taken when de-icing aircraft on the ground. TYPE 1 FLUID-A Newtonian fluid that have a high concentration of propylene glycol or ethylene glycol. A common fluid used in aircrafts. Has shorter holdover time and lack thickening agents. They are diluted with water in order to achieve a certain freezing point in compliance with application procedure. It is heated whenever used as a de-icing fluid in ensuring it achieves a minimum temperature of 140 F at a nozzle. OAT- Operation Air Traffic PRECIPITATION- Conditions that lead to ice formation on the aircraft. ICAO 9640- International Civil Aviation Organization RE-HYDRATION-Occurs when a thickened fluid is applied repeatedly during dry conditions to prevent either de-icing just before flight or from forming up overnight. It, however, dries up during the flight leaving behind a powder like fluid. ANTI-ICING CODE: indicates the treatment the aircraft has received FREEZING POINT BUFFER: Difference between free point temperature and ambient temperature of the fluid. It involves situations where active precipitation has totally ceased, and the major requirement is to have contamination removed from the aircraft. AOM – Aircraft Operator management Question 5: CAT aircraft maintenance operations on the environmental control, oxygen, fuel and related protection systems are carried out at regular intervals. These are explained in various documents and regulatory procedures, including the Aircraft Maintenance Manual (AMM). Referring to a suitable CAT aircraft AMM (state the aircraft, ATA codes etc.) and other documents as required: a.) Aircraft Maintenance and operations Pneumatic systems (vacuum pressure systems), just like the hydraulic and fuel system, has many rubberized hoses, feet of metal, lines, pups, related valves, and tubing. It is somewhat similar to a hydraulic system though, it has air instead of a fluid. Pneumatic system is important for the operation of an aircraft. The important components of a pneumatic system include inlet Air Filter, Overboard Vent Line, Air Pump, Gauges, system indicators, and Air pump. Various parts of a Pneumatic system play a key role in the overall aircraft performance. For instance, the inlet Air Filter facilitates exhaustion of air, acts as an air filter, regulates pressure and assists in the failure warning system. The system as other system requires constant maintenance. Pneumatic system can fail because of being contaminated, damaged hoses or loos fitting, sudden engine stoppage, and abrupt engine deceleration. These can be prevented through installing backup systems, regularly checking all parts, maintaining parts proficiently and using precision instruments for checking. b.) Safety precautions to be observed when maintaining oxygen systems While working on the oxygen systems, work safety must be maintained at all time. All safety and healthy precautions should be complied alongside other relevant guidelines and regulations. While maintaining the aircraft oxygen system, the following safety precaution must be adhered to. First, one should obtain appropriate authorisation in order work on the aircraft, and always observe all the necessary safety and isolation procedures. Second, one should obtain and use correct documentation namely technical instructions, maintenance documentation, job instructions and aircraft manual. Thirdly, he should acquire the correct equipment and tools for the activity, and always check to ensure these tools are in safe and usable condition and within the current calibration dates. Fourthly, he must adhere to systems or procedures in place for purposes of risk assessment, personal protective equipment, COSHH, and other relevant safety procedures and regulations to help realise a safe system of work. This also involves insuring safe isolation of equipment for oxygen before breaking into it. It is also prudent to ensure the relevant safety devices, as well as physical or mechanical locks are put in place where appropriate. One should use approved precautions for instant removing, testing, and fitting procedures and techniques at all times. Tools and equipment should be returned to the correct storage locations upon completion of any activities, while ensuring work being carried out is correctly recorded and documented. All outstanding tests should be correctly documented. The relevant maintenance schedules should be followed in carrying out the required work. All the maintenance activities should be carried out within the specified limits of personal authority. Maintenance should be carried on any of the following parts of an aircraft system: Crew supply, passenger supply. c.) Safety precautions to be observed when maintaining oxygen systems. Fuel used in aircraft is always in vapour form hence extremely flammable. Therefore, precaution must be taken in order to prevent risk of explosion or fire whenever we work on any fuel system. It is important to take into consideration the following factors. First, the area around should be well-ventilated. This helps in preventing the build-up of fumes. Secondly, avoid working on a building that contains a gas appliance and which have a naked flame or pilot light. All sources of sparks or naked light bulbs should be avoided. Thirdly, while in the vicinity of the fuel, smoking should be avoided at all cost. All electrical equipment that belongs to the garage, workshop or house should be properly checked. Certain electrical appliances for instance cutters and drills, which can create sparks under normal operation are not used in the proximity of the fuel. Fourthly, any split fuel should be mopped and the shop rag disposed of safely. Task 2 Question 1: Using diagrams to explain the function and operation of a basic CAT aircraft pitot-static system down to component level. a.) The basic operation of the airspeed indicator and at least 2 of the errors that may affect its readings. CAT Pitot-static System The system of pitot-static is a sensitive instruments used in the field of in determining the altitude of an aircraft, the trend of an altitude, airspeed and March speed number. Pitot-static system is composed of three instruments: altimeter, indicator, and vertical speed indicator. The three instruments are connected by the static lines with the ram air pressure forming the pitot tube which connects to the airspeed indicator. Vertical speed indicator Figure 1: instrument Flying handbook, Rate of Descent, Climb in Thousands of feet Per Minute An airspeed indicator instrument displays the speed of the craft. The instrument relays information to the pilot in terms of knots of the movement of the aircraft. The indicator is used in almost every operation of flight. Its application comes during descend, landing, cruise and take -off. The airspeed works by measuring the difference in static pressure, which is relayed through the pitot tube (Langton, 2009). However, during the performance of this function, the instrument may relay specific errors. Errors attested to the instrument include positional error where the instrument does not calibrate exact positions. Another form of error that occurs while using the instrument is compressibility error. This occurs when the instrument calibrates only standard pressure of the sea. Vertical speed indicators on the other hand measures the rate of climb of an aircraft as well as descend. The instrument operates by detecting change in air pressure as altitude changes. It works by use of airflow. Typically the more the aircraft descends the faster air flows. Air flowing into the air bottle outside the aircraft indicates that the aircraft is descending. In the case where there is a block in reading pilots would not recognize changes. Static readings in aircrafts are important for humans. Unlike birds created for flights pilots would not recognize lifts or descends which might result in unavoidable accidents or loss of life. b.) The basic operation of the vertical speed indicator Airspeed In a CAT aircraft, airspeed measures the speed relative to the surrounding air. It is used by pilots in all phases of a flight right from take-off, cruise, climb, landing and descent. This way, it helps the pilot maintain specific aircraft airspeeds and the operating conditions based on the operating manual. Airspeed indicators function by measuring difference between the captured static pressure, which is captured through static ports, and the stagnation pressure caused by ram air, also captured through the pitot tube. In an airspeed indicator, its static ports were located on an exterior part of an aircraft at a certain location that is chosen to help in detecting the prevailing atmospheric pressure with minimum disturbance from the aircraft’s presence. The open end on a pitot tube is mounted on the aircraft wing facing the flow of water or air. The air speed indicator measures the existing differences between a sensor in the air stream and the static senor not in air stream. When an aircraft is in a standing mode, the pressure in each of the tubes is always equal. The air speed indicator reads zero. In a flight the rush of air leads to differential pressure between the pitot tube and the static tube. This difference in pressure causes the pointer at an air indicator speed to move. Any increase in the forward speed causes the pressure at the pitot tube to raise. This in turn causes the air pressure to push against a diaphragm, which moves the mechanical pointer connected on the indicator. This indicator is calibrated in such a way as that it compensates for winds flowing in the air current. For most airspeed indicators, were calibrated to be used in sea level standard atmosphere. Whenever the temperature or pressure combination results in a density altitude which goes higher that the sea level, a lower airspeed is indicated on an airspeed. On the contrary, in cases where the density altitude falls below a sea level, airspeed indicator shows a faster airspeed. Question 2: Demonstrate an understanding of the physical principles which govern the operation of air cycle and vapour cycle cooling systems and their associated components a). Air cycle cooling pack with examples of typical air temperatures The Air Condition Pack or the Cooling Pack is the air cycle refrigeration systems, which utilizes the air that passes into and through the aircraft as a refrigerant. This is made possible through a combined compressor and turbine machine referred to as Air Cycle Machine, flow control and valve for temperature, and heat exchangers with the use of the air from the surrounding to dispense any waste heat. Air Cooling Pack provides important sterile, dry and conditioned dust free air to the cabin of the aircraft at a proper temperature, pressure and flow rate to satisfy temperature and pressurization control requirements. It operation is such that the hot and pressurized air that comes from the Bleed System of an aircraft enters the aircraft Primary Heat exchanger. Here, temperature reduced after which it goes to the compressor section of an Air Cycle Machine. Here pressure and temperature are raised again. This air proceeds to the Secondary heat Exchanger where the temperature is again reduced. It finally goes to the Air Cycle Machine’s Turbine section where it expands and releases energy used for the rotation of the Compressor and Turbine wheels, which are on a similar shaft with temperature that drops down to zero degrees Celsius. The water Separator removes and condenses the moisture at this temperature. In summary, the process of operation involves evaporation as well as condensation for cooling equipment. b.) The operating principles of an ejector pump. In an aircraft, an ejector pump operates by using its two inlets to pump in gas and motive fluid. These two components move through a nozzle at a given pressure and speed. The system uses the Bernoulli’s principle by increasing pressure as well as decreasing velocity. The resultant effect causes an imbalance resulting to a body to rise (Langton, 2009). AIR CYCLE COOLING PACK   c.) The operating principles of an ejector pump An ejector pump operating principle is similar to the operating principle of a venturi tube. It works by converting a high pressure or small-volume input motive flow into a throat on a unit of the nozzle into a low-pressure/high-volume at a throat of the nozzle. The motive flow for the main pump and the scavenge is provided by a high-pressure section of an associated engine pump. Question 5: Use diagrams to explain the function and operation of a CAT aircraft pressurisation system down to component level a.) Aircraft Pressurization system The below figure represents a typical aircraft pressurization system. An aircraft altitude refers to the height of ascend of the aircraft from the ground. The rate of climb relates to the speed of this ascend. Cabin altitude refers to a height of commercial flight that ranges around 8,000ft as the maximum level, and the climb is an increase of air pressure in the aircraft. Cabin pressurization control depends on the outflow valve which releases pressure to a constant level (Jabbal, & Crowther, 2010). The term maximum cabin deferential refers to the pressure inside and outside a pressurized aircraft. An example of maximum cabin differential is for the Boeing 787 dream liner that maintains a 6,900ft. Diagram of a possible fault in an aircraft. Figure 03: Pressurization subsystem schematic. b.) Describe the operation of the cabin pressure outflow valve Outflow valve used in the aircraft pressurization system regulate the amount of air required to be released from a cabin to help keep the cabin within the needed amount of pressurization. It controls the pressure in the air cabin. When more air is pumped into the air cabin than is needed, the outflow valve controls the amount of air allowed to escape in order to help maintain pressure within the cabin at a correct level. The cabin pressure regulator controls he outflow valve. This means that it protects an aircraft from being under-pressurized or over-pressurized by employing safety valves. Whenever a differential pressure becomes too high, and outflow valves do not rectify the problem, the safety valves opens. In the process reduce the cabin pressure. Similarly, when the cabin pressure on the ground becomes lower than the outside air pressure, negative pressure valves respond by equalizing the situation. c.) The meaning of the term ‘maximum cabin pressure differential’ (P) and give at least one example, citing the aircraft, of a typical value for P. Pressurized aircraft enables a pilot to fly at a higher, faster, and more fuel efficient altitudes at which human physiology could suffer without any help. Pressurizing the inside of an aircraft cabin makes passengers to feel as though they are comfortably still on the surface of the earth, instead of a hypoxic, cold, and high-altitude environment. Maximum Cabin differential pressure (P), is the difference between pressure outside the aircraft and pressure inside the aircraft. Maximum Cabin differential pressure (P) has some engineered limitation in order to avoid putting much pressure or rather overstressing the cabin. Therefore, it is important to maintain a proper pressure differential because it helps maintain safety. Question 4: The compass onboard an aircraft may be difficult to read at times. a.) Instrument is used normally to confirm heading Magnetic compass b.) Compare the operation of this instrument, its possible power supplies, and its limitations in a light aircraft to the CAT aircraft equivalent. A magnetic compass is a navigational instrument likely found in aircrafts. It gives direction where the pilot is heading. Compass gets power from the aircraft in terms of DC current. The instruments have its setbacks in terms loss of degrees due to other forces making it unreliable. Aircrafts retain magnetic compass, head indicator for emergency reasons. This instruments layout is at the cockpit. In cases of faults CAT has warning captions. These captions include fire bells, configuration warnings, and engine malfunction warnings. The diagnosis of such warning might be to put of fire, repair devices or inform control towers before landing. Question 5: CAT aircraft retain some basic instrumentation for possible use in an emergency. CAT aircraft retain some basic instrumentation for possible use in an emergency. a.) AIRCRAFT BACKUP AND EMERGENCY SECONDARY POWER APPARATUS There are auxiliary hydraulic and electrical power sources for an aircraft systems. One of these improves is the compound hydraulic generator or motor, which is mechanically coupled to the electrical generator/motor. This device is called a Compound hydraulic/electro Motor Generator Pump (CMGP). b.) CMGP system allows hydraulic power to be supplied from any electric power source or an electric power from a hydraulic source of power. Another improvement entails a combination of a ducted air turbine drive (ram) with the CMCP, which defines means of providing continuous hydraulic and electric power to an aircraft in case all aircraft engines that are driven by power sources totally fail. For the modern CAT aircraft, power systems are important because they are the sources of forces for an aircraft control. Most of the modern CAT aircraft favor mechanical backup to purely powered controls for dispense. These aircrafts also have hydraulic powered surface actuators, electronically controlled, electrically controlled and electrically powered actuators. A combination of both is also highly favored. For powered controls, sufficient power is required to be available always in order to maintain the aircraft control in the event of a foreseeable failure. Power required to control an aircraft must be available continuously so that in the event that all the aircraft engines including the auxiliary power units fail. Question 6: CAT aircraft systems include warnings on the flight deck to assist safe operation of these systems, particularly in flight. Heat, voltage, current, flow and pressure outside design limitations in some systems may result in warnings. A diagnosis process will then need to be followed, perhaps resulting in a tech.log entry. Choose any three warnings that may be displayed for an aircraft (specify) and for each one: For commercial Aircrafts to navigate efficiently on the runway various principles and instruments come into action. Various instruments are essential for takeoff as well as landing. For typical Commercial aircrafts, radio beam transmitters are important for providing directions for approaching aircrafts. For this principle to function, a pilot needs to tune their receivers to receive airport signals. This beam of signal provides safe lateral and vertical landing signals. An approaching aircraft precision landing depends on high precision landing guidance, which constitutes a combination of high intensity lighting system and radio signals (Nolan, 2010). High intensity lighting systems applies in situations where there is fog, mist and blowing snow discouraging safe landing. References Lovelace II, W. R. 2012. "Aero medical aspects of cabin pressurization for military and commercial aircraft." Journal of the Aeronautical Sciences (Institute of the Aeronautical Sciences), 13 (3), Pp.17-38. Langton, R. 2009 . Aircraft fuel systems. New York: John Wiley & Sons, Ltd, Jabbal, M., S. C., & Crowther W.J. 2010. "Active flow control systems architectures for civil transport aircraft." Journal of Aircraft 47 (6), Pp. 1966-1981. Marwedel, S, M, & Jörg R.2011 "Platform for aircraft maintenance services and asset management." European Patent No. EP 2378468. 19 Oct. Nolan, M. S.2010. Fundamentals of air traffic control.New York: Cengage Learning. Read More