Lecture 10-Traffic Collision & Avoidance System(TCAS)

Lecture 10: Traffic alert and Collision Avoidance System (TCAS)

By: Zuliana Ismail,2010

Learning Outcomes Home

Previous

Next

Help

• At the end of this lecture, the student should be able to: – Describe the theory of early warning system including TCAS

What is TCAS Home

• TCAS stand for Traffic alert and Collision Avoidance System

Previous

Next

Help

• TCAS is a special system designed to reduce the incidence of Mid-air Collisions (MAC) between aircraft. • According to ICAO, all aircraft with MTOW over 5700 kg or carry more than 30 passengers are compulsory to equipped with TCAS.

Mid-Air Collision (MAC) Home

Previous

Next

Help

Worst MAC in History •Saudi Arabian Airlines VS Kazakhstan Airlines , 1996 (349 people killed) •Bashkirian Airlines collided with DHL,2002 (71 People Killed)

A mid-air collision is an aviation accident in which two or more aircraft come into contact during flight.

TCAS Equipments Home

TCAS Antenna Previous

Next

Help

TCAS Display

HOW TCAS WORKS Home

Previous

Next

Help

• TCAS operates similar as Secondary Surveillance Radar (SSR), but in air to air role.

HOW TCAS WORKS Home

Previous

Next

Help

• 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

Previous

Next

Help

• Targets (other aircraft) are displayed on the TCAS screen as different symbols which show level of threat. • Aircraft relative altitude also will be displayed. – 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.

Traffic Advisory (TA) & Resolution Advisory (RA) Home

Previous

Next

Help

Determination of the alerts: TA & RA Traffic Advisory (TA) Intruder be at 45 help the pilots in the visual search and 35 seconds for the intruder aircraft, and alert from the collision them to be ready for a potential area. resolution advisory Resolution Advisory (RA) Intruder be at 30 avoidance maneuvers and 20 seconds recommended to the pilot. from the collision area.

AUDIO WARNING

“Traffic, Traffic”

“Climb, Climb” “Descent, Descent”

• Range = 14 NM

• Maximum number of aircraft processed = 30

TYPICAL TCAS DISPLAY Home

Previous

Next

Help

TCAS Display In modern glass cockpit aircraft, the TCAS display may be integrated in the Home Navigation Display Previous

Next

Help

TCAS Advantages Home

Previous

Next

Help

• Highly accurate distance measurements, with a one-second refresh rate.

• All threats taken into account • Detection of all transponding aircraft, including those which are not displayed on the air traffic controller’s screen • Independent system, which acts as a last resort measure to avoid mid-air collision when other safety precautions fail. • TCAS reduced the risk of mid-air collision

TCAS Limitations Home

Previous

• No detection of aircraft without or not operating transponders (e.g. VFRs, military flights)

Next

Help

• No knowledge of the pilot’s intentions and of the ATC separation minima

• Basic display: no identification, no past positions, no speed vector • Sometime generate unnecessary alerts.