TCAS

Question 1

TCAS

Answer 1

Traffic Collision Avoidance System

Question 2

TCAS regulations

Answer 2

The Airborne Collision Avoidance System II (ACAS II) was introduced in order to reduce the risk of mid-air collisions or near mid-air collisions between aircraft. It serves as a last-resort safety net irrespective of any separation standards.
ACAS II is an aircraft system based on Secondary Surveillance Radar (SSR) transponder signals. ACAS II interrogates the Mode C and Mode S transponders of nearby aircraft (‘intruders’) and from the replies tracks their altitude and range and issues alerts to the pilots, as appropriate. Non-transponding aircraft are not detected.
ACAS II works independently of the aircraft navigation, flight management systems, and Air Traffic Control (ATC) ground systems. While assessing threats it does not take into account the ATC clearance, pilot’s intentions or autopilot inputs.
Currently, the only commercially available implementations of ICAO standard for ACAS II (Airborne Collision Avoidance System) are TCAS II versions 7.0 and version 7.1 (Traffic alert and Collision Avoidance System). ICAO Annex 10 states that new ACAS installation after 1 January 2014 must be version 7.1 compliant and the existing units must be upgraded to version 7.1 before 1 January 2017.

Question 3

Types of TCAS

Answer 3

• ACAS I Gives Traffic Advisories (TAs) but does not recommend any manoeuvres. The only implementation of the ACAS I concept is TCAS I.
• ACAS II Gives Traffic Advisories (TAs) and Resolution Advisories (RAs) in the vertical sense (direction).
• ACAS III Gives TAs and RAs in vertical and/or horizontal directions. Also referred to as TCAS III and TCAS IV. Not currently implemented and unlikely to be in the near future.

Question 4

TA (traffic advisory) may become RA (resolution advisory) in … seconds

Answer 4

15

Question 5

TA … until CPA

Answer 5

20 - 45

Question 6

RA … until CPA

Answer 6

20 - 35

Question 7

In case of RA, the pilot must react in … seconds

Answer 7

5

Question 8

In case of RA:

Answer 8

• disconnect AP
• DO NOT follow the FD bars
• DO NOT change the altitude set on the AFCS

Question 9

RA in approach …

Answer 9

CLIMB and execute a GO AROUND

Question 10

In case of TCAS RA, does the ATC have any responsibility ?

Answer 10

!!! NO, all maneuvers must be executed in concordance with the actions displayed by the instrument !!!

Question 11

OPEN DIAMOND

Answer 11

Shows other traffic. Range and bearing of other aircraft within surveillance range and selected range and altitude for display.

Question 12

SOLID DIAMOND

Answer 12

Traffic within ± 1200 ft and 6 NM of own aircraft.

Question 13

SOLID CIRCLE

Answer 13

Intruder. TA generated. Range and bearing relative to own aircraft.

Question 14

SOLID CUBE

Answer 14

Traffic generates conflict. RA generated range and bearing relative to own aircraft.

Question 15

TRAFFIC ARROW

Answer 15

(same color as associated traffic symbol): climb or descent rate (>500 ft/min) of intruder aircraft

Question 16

RNG

Answer 16

Range push button selects range of display. (6NM or 12NM)

Question 17

RANGE RING

Answer 17

(white) 2 miles radius range about own aircraft

Question 18

A/B Mode button

Answer 18

Select display of traffic (relative to own aircraft altitude)
- ABOVE: +9900 ft to –2700 ft
- BELOW: +2700 ft to –9900 ft
In normal position, viewing of traffic from 2700 ft below
to 2700 ft above

Question 19

GREEN ARC

Answer 19

Recommends vertical speed to resolve corrective resolution advisory.

Question 20

RED ARC

Answer 20

Do not enter range if vertical speed is outside of arc (preventive);
Exit range if vertical speed is within arc (corrective resolution)

Question 21

There can be a case where the threat aircraft track on altitude information is lost
during an RA. In this case, the RA will terminate …

Answer 21

Without a “CLEAR OF CONFLICT” annunciation

Question 22

TCAS RA …

Answer 22

• CLIMB: MCT, CL 100% OVRD

- RADIO: “TCAS RA” and when it’s the case, “CLEAR OF CONFLICT”

Question 23

TCAS 7.1 , new mode …

Answer 23

Level off and reversal of RAs

Question 24

TCAS CLIMB …

Answer 24

▶️PWR MGT selector …… CORRECT RATING (MCT en route or TO in other phases e.g. TO, APP and LDG)
▶️CL ….. 100% OVRD