FINDING FLIGHT DATA RECORDER USING ROBOTIC FISH R.VAISHNAVI, K.SUPRAJAA. Department of Electronics and communication engineering, Bannari amman institute of technology, erode, Tamilnadu, India. E-mail: vaishnavi.ec14@bitsathy.ac.in Abstract One of the first pieces of techno-speak that springs to mind when we hear of an aviation disaster is BLACK BOX.Any commercial aero plane or corporate jet is required to be equipped with a cockpit voice recorder and a flight data recorder. It is these two items of separate equipment which we commonly refer to as a Black Box. While they do nothing to help the plane when it is in the air, both these pieces of equipment are vitally important at times of the plane crash, as they help crash investigators find out what happened just before the crash. But still, there is a list of aircraft, aviators or air passengers who have disappeared in flight for reasons that have never been definitely determined, particularly in cases where the air frame of the aircraft or body of the person has never been recovered. This is because, the key - the BLACK BOX, that explains the details of the disappearance of the flight has also vanished taking all the evidences of the crash. Our main intention is to find this BLACK BOX by a ROBOTIC FISH. 1. Introduction More than about 150 air crashes happened till now are unpredictable. For an instance, let us look about the recent Malaysian air crash. The Malaysia Airlines Flight 370 (MH370/MAS370) was a scheduled international passenger flight that disappeared on 8 March 2014, while flying from Kuala Lumpur International Airport near Kuala Lumpur, Malaysia, to Beijing Capital International Airport in Beijing, China. The search has occurred for more than 365 days(one year) to find a single wing of the flight. The rest of the parts still remain a mystery. 72
2. Hidden crisis The situation where the Black Box is out of the range and remains a mystery occurs when it falls into the sea. Usually the Black Box is fitted with an UNDERWATER LOCATOR BEACON (ULB). The device is activated as soon as the recorder comes into contact with water and it can transmit froma depth as deep as 14,000 feet. But the problem is that the ULBcan work only for a short period of 30 days. So, we need *LONGER LIFETIME OR * A FASTEST WAY OF DETECTING THE BLACK BOX. A R I G H T W I N G F L A P E R O N, W H I C H W A S L A T E R C O N F I R M E D T O B E F R O M F L I G H T 3 7 0, W A S F O U N D O N T H E B E A C H O F R E U N I O N I S L A N D I N T H E I N D I A N O C E A N, 1 6 M O N T H S A F T E R F L I G H T 3 7 0 D I S A P P E A R E D : Thus,it is clear that the search has occurred for more than 365 days(one year) to find a single wing of the flight. The rest of the parts still remain a mystery. 3.Working process of a black box Older black boxes used magnetic tape, a technology that was first introduced in the 1960s. Magnetic tape works like any tape recorder. The Mylar tape is pulled across an electromagnetichead, which leaves a bit of data on the tape. These days, black boxes 73
use solid-state memory boards, which came along in the 1990s. Solid-state recorders are considered much more reliable than their magnetic-tape counterparts. Solid state uses stacked arrays of memory chips, so they don't have moving parts. With no moving parts, there are fewer maintenance issues and a decreased chance of something breaking during a crash. Data from both the CVR and FDR is stored on stacked memory boards inside the crash-survivable memory unit (CSMU). The memory boards have enough digital storage space to accommodate two hours of audio data for CVRs and 25 hours of flight data for FDRs. Airplanes are equipped with sensors that gather data such as acceleration, airspeed, altitude, flap settings, outside temperature, engine performance, and cabin temperature and pressure. Magnetic-tape recorders can track about 100 parameters, while solid-state recorders can track a lot more. 74
i) Cockpit Voice Recorders In almost every commercial aircraft, there are several microphones built into the cockpit that listen to flight crew conversation. These microphones also track any ambient noise in the cockpit, such as switches being thrown or any knocks or thuds. There may be up to four microphones in the plane's cockpit, each connected to the cockpit voice recorder (CVR). Microphones send audio to the CVR, which digitizes and stores the signals. In the cockpit, there is also a device called the associated control unit, which provides preamplification for audio going to the CVR. The four microphones are place in the pilot's headset, co-pilot's headset, headset of a third crew member (if there is a third crew member) and near the center of the cockpit, to pick up audio alerts and other sounds. Most magnetic-tape CVRs store the last 30 minutes of sound. They use a continuous loop of tape that completes a cycle every 30 minutes. As new material is recorded, 75
the oldest material is replaced. CVRs that use solid-state storage can record two hours of audio. Similar to the magnetic-tape recorders, solid-state recorders also record over old material. ii) Flight Data Recorders The flight data recorder (FDR) is designed to record the operating data from the plane's systems. There are sensors wired from various areas on the plane to the flight-data acquisition unit, which is wired to the FDR. So whenever the pilot flips a switch or twiddles a knob, the FDR records each action. In the U.S., the Federal Aviation Administration (FAA) requires that commercial airlines record a minimum of 11 to 29 parameters, depending on the size of the aircraft. Magnetic-tape recorders have the potential to record up to 100 parameters. Solid-state FDRs can record hundreds or even thousands more. On July 17, 1997, the FAA issued a Code of Federal Regulations that requires the recording of at least 88 parameters on aircraft manufactured after August 19, 2002. Here are a few of the parameters recorded by most FDRs: Time Pressure altitude Airspeed Vertical acceleration Magnetic heading Control-column position Rudder-pedal position Control-wheel position Horizontal stabilizer Fuel flow Solid-state recorders can track more parameters than magnetic tape because they allow for a faster data flow. Solid-state FDRs can store up to 25 hours of flight 76
data. Each additional parameter recorded by the FDR gives investigators one more clue about the cause of an accident. Airplane crashes are violent affairs. In many such accidents, the only devices that survive are the crash-survivable memory units (CSMUs) of the flight data recorders and cockpit voice recorders. Typically, the rest of the recorders' chassis and inner components are mangled. The CSMU is a large cylinder that bolts onto the flat portion of the recorder. This device is engineered to withstand extreme heat, jarring crashes and tons of pressure. In older magnetic-tape recorders, the CSMU is inside a rectangular box. Using three layers of materials, the CSMU in a solid-state black box insulates and protects the stack of memory boards that store the digitized data. Here's a closer look at the materials that provide a barrier for the memory boards, starting at the innermost barrier and working our way outward: Aluminum housing -- There's a thin layer of aluminum around the stack of memory cards. High-temperature insulation -- This dry-silica material is 1 inch (2.54 centimeters) thick and provides high-temperature thermal protection. This is what keeps the memory boards safe during post-accident fires. Stainless-steel shell -- The high-temperature insulation material is contained within a stainless-steel cast shell that is about 0.25 inches (0.64 centimeters) thick. Titanium can be used to create this outer armor as well. These hardened housings are incredibly important. Without adequate protection, all of the flight data would be destroyed. So to make sure that data stays safe, engineers attack their black boxes with full fury to see if their products can withstand extreme abuse. 3.Power supply Both FDRs and CVR in the black box run off of a dual voltage power supply (115 VAC or 28 DC) which gives the units the flexibility to be used in a variety of aircraft. The 77
batteries are designed for 30-day continuous operation and have a six-year life. The batteries are of lithium batteries. So, the lifetime of the battery has to be increased to find out the black box. The recent ULB batteries are proposed to design with longer life time for about 90 days. 4. Manufacturing process of a black box In many of the worst aviation accidents, the only devices to survive in working order are the Crash Survivable Memory Units (CSMUs) in the black boxes. The remaining of the recorders, including the external case and other internal components, are often heavily damaged. The CSMU, however, is contained within a very compact cylindrical or rectangular box designed to safeguard the data within against extreme conditions. The box is composed of three layers to provide different types of protection to the recording medium. The outermost shell is a case made of hardened steel or titanium designed to survive intense impact and pressure damage. The second layer is an insulation box while the third is a thermal block to protect against severe fire and heat. Together, these three layered cases allow the FDR and CVR to survive in all the most extreme crash conditions. 78
Current regulations require the black boxes to survive an impact of 3,400 g's for up to 6.5 milliseconds. This rapid deceleration is equivalent to slowing from a speed of 310 miles per hour (500 km/h) to a complete stop in a distance of just 18 inches (45 cm). This requirement is tested by firing the CSMU from an air cannon to demonstrate the device can withstand an impact force at least 3,400 times its own weight. The black boxes must also survive a penetration test during which a steel pin dropped from a height of 10 ft (3 m) impacts the CSMU at its most vulnerable point with a force of 500 pounds (2,225 N). In addition, a static crush test is conducted to demonstrate that all sides of the CSMU can withstand a pressure of 5,000 pounds per square inch (350 kg/cm²) for five minutes. The fire resistance of the CSMU is further tested by exposing it to a temperature of 2,000 F (1,100 C) for up to an hour. The device is also required to survive after lying in smoldering wreckage for ten hours at a temperature of 500 F(260 C). 79
5.Robotic fish One of the expeditious way is to have a ROBOTIC FISH besides the black box. The BLACK BOX and ROBOTIC FISH are placed in the BOX which is fitted to the tail of the plane. Once the plane crashes, the box falls down. An accelerometer is fitted to the box which detects the free fall. The position of latitude and longitude are recorded in it. The box is made to be indestructible in the same way as the black box is made. Once the black box falls into the sea the float sensor separates the robotic fish from the black box. The robotic fish has an SD card inside it. The accelerometer reading, GPS information etc.., are stored in the SD card of the fish simultaneously. The black box goes down underwater. But the fish which has all of its information stored safer carries the information. The robotic fish is also accompanied by GPS tracking system. With all these assistances, the robotic fish progresses till it gets the signal to interface with us to the nearby destination(land area or ships). Once we have an interface with the robotic fish, the SD card can be retrieved which has 80
the information of the black box. An ultrasonic sensor is used to move the robotic fish in the correct path to safeguard from the obstacles. Thus the BLACK BOX could be RETRIEVED easier which helps to find out the mystery. Conclusion Its time to unwrap the mystery now. Nowadays flight missing is an important problem and by this technique we can find a solution for that.thus the black box can be detected much earlier than the normal times using the latitudinal and longitudinal information recognized by the GPS tracking system which is stored in the SD card located in the ROBOTIC FISH. Thus the technique proposed above will be helpful in Locating the missing flight. Reduces time delay in finding the black box. Decrement the Cost of dispatching search teams. References [1]. http://www.dw.com/en/how-does-a-black-box-work/a-17907283 [2]. http://science.howstuffworks.com/transport/flight/modern/black-box.htm [3]. http://www.iasa.com.au/folders/safety_issues/dfdr-cvr/howblackboxworks.html [4]. http://www.robotic-fish.net/index.php?lang=en&id=robots [5]. http://splash.abc.net.au/home#!/media/2269214/using-mechatronics-to-build-a-robot-fish [6]. http://science.howstuffworks.com/transport/flight/modern/black-box4.htm 81