The Tcas Airborne Collision System Analysis

Airborne Collision System/TCAS Analysis

The TCAS (traffic collision avoidance system) was introduced to reduce the risks associated to the mid-air collision between aircraft. The TCAS serves as a last resort safety system no matter the separation standard, and the TCAS is "an aircraft collision avoidance system" (Damidau, Save, Sellier, 2010 p 2). that has been designed to reduce the mid-air collision incidence. The TCAS is also used to monitor the airspace as well as other aircraft, which has been equipped with the corresponding active transponder. The TCAS is used to warn pilot, and other transponder equipped aircraft that may pose a threat to the MAC (mid-air-collision). In essence, the TACS is an airborne collision avoidance system that has been mandated by the ICAO (International Civil Aviation Organization), which needs to be fitted into all aircraft with a load of over 5,700 kg before a take off or the aircraft that has been authorized to carry above 19 passengers. For example, it is mandatory to install the TCAS I in aircraft carrying between 10 and 30 passengers. The TCAS/ACAS is SSR (secondary surveillance radar) or transponder signal used to advise pilot regarding a system failure.

System Analysis

TCAS is equipped with an appropriate interrogates and transponder used to determine the position of an aircraft using the 1.03 GHz radio frequency. The TCAS has the following system components:

TCAS computer unit: The computer system is used for the intruding tracking, airspace surveillance, threat detection, altitude tracking and resolution advisory. Moreover, the TCAS processor uses the radar altitude, pressure altitude, and discreet status to avoid collision, which also determine a level of protection within the TCAS aircraft.

Antennas: The TCAS antenna is used to receive signal and enable the S transponder to receive 1030 MHz.

Cockpit presentation: The RA display and traffic display consist of TCAS interface used to display essential information to the control unit.

The goal of the TCAS is to limit the consequence hazards within the aircraft environment. The hazard refers to any condition that is able to cause injury or death to personnel. Hazard is also a damage to a system or loss of property or equipment. It is essential to realize that hazard can occur when the aircraft is about to take off, in the air, or when an aircraft is about to land. One of the strategies that the TCAS employs to avoid hazard is the ability to determine if a treat or potential collision is about to occur. In this sense, the TCAS will interact with aircraft using the S or C transponder. The system will assign a unique 24-bit identifier to the aircraft with S transponder.

The next step is to automatically negotiate a mutual avoidance strategy to avoid conflict between two aircraft. The strategy is by communicating to the flight crew using a synthesized voice instruction. Different types hazards can occur if not immediately mitigated, these hazards are as follows:

STCA vs. Conflict

Air Traffic Control vs. STCA

Air Traffic Control vs. TCAS

Crew vs. Air Traffic Control Avoiding Instruction

Crew vs. TCAS

Crew vs. RA Report

STCA vs. TCAS.

Some of these hazards can occur if there is a lack of ATC to solve arising short-term conflict. Moreover, a late instruction to solve soft-term conflict can also lead to a hazard. Insufficient instruction, incorrect instruction or lack of instruction to TCAS from ATC can also lead to a hazard.

Impact of the items in the PHA if not Mitigated

The item PHA (process hazard analysis) ought to be mitigated because it can cause several negative effects if not immediately mitigated. For example, STCA vs. conflict can lead to an aircraft collision. Moreover, lack of instruction, insufficient instruction or late instruction can make an aircraft to develop fault, lose control and consequently lead to aircraft crash. (Damidau, Save, Sellier, M. 2010).

Risk Analysis Matrix

This section develops the risk matrix analysis of each item to reveal the impact the hazard.

Category

Basic Type of Hazard

Severity

Class

STCA vs.

Conflict

Lack of genuine and good STCA alert

3

Late STCA alert

3

Delayed STCA alert

4

False STCA alert

3/4

Nuisance STCA alert

3/4

ATC vs.

STCA

Lack of quick reaction to a genuine STCA alert

3

Late reaction to a genuine STCA alert

4

Insufficient ATC reaction linking to a genuine STCA alert

3/4

Incorrect reaction to a genuine STCA alert

3/4

ATC vs.

TCAS