1. Definition2. Impetus3. Specifications4. Parameters5. Advantages/disadvantages

TCAS (DEFINITION)

Traffic Collision Avoidance System (tee-kas)

Designed to reduce the incidence of mid air collisions (MAC) between aircraft

It monitors the airspace around an aircraft corresponding active transponder,

Independent of air traffic control

Warns pilots of the presence of other transponder-equipped aircraft

Mandated by the International Civil Aviation Organisation (ICAO)

All aircraft with a maximum take-off mass over 5,700 kg (12,600 lb) or authorized to carry more than 19 passengers. (31 March 2006)

TCAS (Impetus)

The Grand Canyon MAC in 1956; All 128 on board both flights perished. It was the first commercial airline crash to result in more than 100 deaths, and led to sweeping changes in the control of flights

In 1978 (PSA) Flight 182, a commercial airliner collided with a private Cessna over San Diego (144 deaths, including 7 on the ground)

TCAS I developed in 1989 TCAS II developed in 1993

The Uberlingen (Germany) MAC between a Boeing 757 and a Tu-154 in 2002, killing 71

TCAS (Specifications)

TCAS (Specifications)

TCAS antenna surveys the area around the aircraft and sends out signal

Other aircraft equipped with TCAS will reply

Calculates tracked aircraft position

Targets are displayed in TCAS screen as different symbols according to level of threat

TCAS can not display other aircraft w/o TCAS antenna/Transponder

Maximum number of aircraft processed is 30

TCAS (Specifications)

TCAS (Parameters)

1. Traffic Advisories (TA) : When received pilots are instructed to initiate a visual search for the traffic causing the TA. If the traffic is visually acquired, pilots are instructed to maintain visual separation from the traffic

No horizontal maneuver Intruder between 40 and 25 seconds Audio Warning “Traffic, Traffic”

2. Resolution Advisories (RA) : When an RA is issued, pilots are expected to respond immediately The ATC is no longer responsible for separation of the aircraft involved in the RA until the conflict is terminated Intruder 25 seconds away Audio Warning “Climb, Climb” or “Descend, Descend”

TCAS (Parameters)

TCAS (Advantages/Disadvantages)

Advantages

1. All threats taken into account2. All transponding aircraft detected (even the ones ATC not following)3. Independent4. Reduces the risk of MAC

Disadvantages

1. Can`t display aircraft w/o TCAS antenna/transponder2. Basic information no past position, no identification3. Sometimes creates unnecessary alerts