Fundamentals of aircraft design
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The document discusses the key components and purpose of an aircraft's black box recorder system. It explains that commercial aircraft are required to have a cockpit voice recorder and flight data recorder, commonly referred to together as the black box. These recorders are vital for investigating crashes as they can provide information on what happened before impact. The cockpit voice recorder specifically records audio from the cockpit to help determine things like engine sounds, crew communication, and the timing of events. Both recorders are designed to withstand high heat and pressure and contain underwater locator beacons to help with recovery from crashes at sea.
Fundamentals of aircraft design
- 1. By :- Tauseef khan Vit university Tauseefkhan529@gmail.com
- 2. FUNDAMENTALS OF AIRCRAFT DESIGN The major structural component of a conventional aircraft includes the fuselage, wings, empennage, control surfaces & landing gear. The empennage comprises of tail plane & fin. The control surface comprises of ailerons, flaps, elevators & rudder. The fuselage is main body mounting the operating crew, passengers, payloads & most of aircraft system. The wings & empennage are attached to the fuselage. The ailerons & flaps are attached to the wings. The elevators are attached to the tail plane & the rudder is attached to the fin. The leading gear & power plant are accommodated in the wings & the fuselage depending on the configuration. The wings provide the lift. The control surfaces are the means to control the movement of aircraft in flight about the longitudinal and vertical axis. The landing gear supports the aircraft on the ground. The power plant provides the thrust. AIRCRAFT FORWARD PRINCIPLE OF FLIGHT When aircraft is at rest, its weight is supported by landing gear. As the engine are opened up to full power, the aircraft starts to move forward on its wheel due to the ‘thrust’ created by the reaction on the aircraft forced rearwards by propeller rotation. As the aircraft moves forward, the various part of the
- 3. aircraft offer resistance to the forward motion called ‘drag’. The drag is zero at the commencement of the takeoff & builds up in proportion to the square of the forward speed. The wings are specially shaped with an aero foil section. There is an area of low pressure above the wings & area of high pressure below the wings. The net effect causes a vertical component called ‘lift’. Lift increases by increasing angle of attack and a stage is soon reached when lift force is greater than the weight of the aircraft.
- 4. BLACK BOX Often one of the first pieces of techno-speak that springs to mind when we hear of an aviation disaster - and a catch-all phrase popular with the media - is ‘Black Box,’ but how much do you really know about these vital pieces of equipment? 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 should the plane crash, as they help crash investigators find out what happened just before the crash. (Black box external and internal)
- 5. Often, for example when a plane crashes into the sea, as happened with the 1985 bombing of Air India flight 182 by Sikh terrorists over the Atlantic Ocean just west of Ireland, investigators have very little to go on – on this specific occasion the plane crashed before the pilot could even issue a mayday signal and much of the debris sank into the sea, leaving few clues. Today, the Black Box is still just as vitally important in helping piece together the causes of a plane crash, as seen by the discovery of the Black Box in the Mexico plane crash that killed fourteen, including the interior minister of Mexico on 4th November, 2008. To help locate the cockpit voice recorder and a flight data recorder in the aftermath of a plane crash that occurs at sea, each recorder has a device fitted to it known as an Underwater Locator Beacon (ULB). The device is activated as soon as the recorder comes into contact with water and it can transmit from a depth as deep as 14,000 feet. THE COCKPIT VOICE RECORDER The main purpose of the Cockpit Voice Recorder is, unsurprisingly, to record what the crew say and monitor any sounds that occur within the cockpit. While investigators might be interested in any witty banter between pilots that went on just before an explosion or plane
- 6. malfunction, trained investigators are keen to pick up on sounds such as engine noise, stall warnings or emergency pings and pops. Investigators are so skilled that they are then able to work out crucial flight information such as the speed the plane was travelling and engine rpm and can sometimes pinpoint the cause of a crash from the very sounds the plane was making before it crashed. The Cockpit Voice Recorder is also extremely important for determining the timing of events as it contains information such as communication between the crew and ground control and other aircraft. The Cockpit Voice Recorder is usually located in the tail of a plane. A cockpit voice recorder (CVR) is a flight recorder used to record the audio environment in the flight recorder of an aircraft for the purpose of investigation of accidents and incidents. This is typically achieved by recording the signals of the microphones and earphones of the pilots' headsets and of an area microphone in the roof of the cockpit. The current applicable FAA TSO is C123b titled Cockpit Voice Recorder Equipment. The details for a CVR are as follows- Time recorded: 30 min continuous, 2 hours for solid state digital units Number of channels: 4 Fire resistances: 1200 deg. C /30 min
- 7. Water pressure resistance: submerged 20,000 ft. underwater locator beacon: 37.5 KHz Battery: 6yr shelf life, 30 day operation