Traffic alert and Collision Avoidance System (TCAS)
Exercises Home
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• Explain how Traffic alert and Collision Avoidance System (TCAS) work?
Traffic alert and Collision Avoidance System (TCAS) Home
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TCAS is a special system designed to reduce the incidence of mid-air collisions between aircraft.
Mid-Air Collision Home
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Worst Mid-Air Collision in History Saudi Arabian Airlines VS Kazakhstan Airlines Home
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• Mid-air collision occurred on 12 November 1996 • Saudi Arabian Airlines (Boeing 747)from New Delhi, India, to Dhahran, Saudi Arabia. • Kazakhstan Airlines (Ilyushin Il-76) from Kazakhstan to New Delhi • Both aircrafts collided at India airspace.
• All 349 people on board both flights were killed, making it the WORST mid-air collision in history
Causes of Accident Home
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• Failure of the Kazakh pilot to follow ATC instructions. – Commanded by ATC to descend at altitude 15’000ft, but he descend to altitude 14’500ft.
• Lack of English Language Skills of Kazakh pilot. • Indira Gandhi International Airport did not have secondary surveillance radar, which produces exact readings of aircraft altitudes; instead the airport had outdated primary radar, which produced approximate readings.
Traffic alert and Collision Avoidance System (TCAS) Home
• TCAS is a special system designed to reduce the incidence of mid-air collisions between aircraft.
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• It is also known as ACAS (Airborne Collision Avoidance System)
• TCAS system capable of displaying conflicting traffic and providing resolution advice. • According to ICAO, TCAS is mandatory for all aircraft with MTOM (maximum take-off mass) over 5700 kg or carry more than 19 passengers
Bashkirian Airlines collided with DHL Home
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• Bashkirian Airlines (Tupolev Tu-154M) passenger jet en route from Moscow to Barcelona. • DHL Flight 611 (Boeing 757) cargo jet flying from Bergamo, Italy, to Brussels, Belgium. • The two aircraft collided in mid-air on 1 July 2002, in Germany airspace killing all 71 aboard both aircraft. • The Investigation found that the accident had been caused by
problems within the air traffic control system and problems with the use of the Traffic alert and Collision Avoidance System (TCAS).
• On 24 February 2004, the ATC who was on duty at the time, was stabbed to death by a man who had lost his wife and two children in the accident.
TYPICAL TCAS DISPLAY Home
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TCAS Display Home
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In modern glass cockpit aircraft, the TCAS display may be integrated in the Multifunction Display (MFD)
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HOW TCAS WORKS Home
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• TCAS works as a back up to the ATC system and the ‘see & avoid’ system. • TCAS consists of antennas on aircraft body, computer processor & TCAS display inside cockpit. • TCAS antenna continually surveys the airspace around an aircraft & transmit the signal. • Other aircraft that also equipped with TCAS in the surrounding area will reply the signal. • TCAS continuously calculates tracked aircraft position, therefore TCAS display constantly updated and provide real time position information.
HOW TCAS WORKS Home
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• Targets are displayed on the TCAS screen as different symbols which show level of threat. • Aircraft relative altitude also will be displayed.
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– Relative altitude is the targets altitude in relation to the aircraft. EX: -03↑ depicts a target 300 feet below and climbing.
• TCAS can not display aircraft without TCAS antenna/transponders.
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CAUTIONS Home
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• TCAS is designed as a tool to improve situational awareness and as a last resort measure to avoid mid-air collision when other safety precautions fail.
• An intimate understanding of each specific system is required in order to accurately interpret the displayed information. • The visual information displayed to the pilot is limited and can be misleading, caution is advised.
