Summary: Traffic Collision Avoidance System

Traffic Collision Avoidance System

Background

The “see and avoid” method of dealing with conflicts in the airspace, with increasing traffic congestion, poses an ever-increasing challenge, and so is deemed to be insufficient in the modern day aviation. Even the early decades of commercial aviation when the traffic was low, there were instances of near-collision and Mid Air Collison which demanded the need for the research into an automatic system that could inform the aircraft of an intruding aircraft and warn the pilots if the planes were on collision course so as to provide the pilots with sufficient time to make certain preventive maneuvers. Considering the safety of aviation, research for such a system was started form as early as the 1950s,

For this purpose, the system scans the surrounding airspace once every second, thus interrogating other transponder- equipped aircraft. So, there is a transponder to transponder communication between the two aircrafts, and so the host aircraft receives information of the other aircraft, and uses the information for predicting the flight path of the aircraft which has been communicated to. Now, if the system discovers that the nearby aircraft is actually on collision course, a cautionary area and a warning area are added, thus new three dimensional air space is created. This is to say that the collision area can change depending upon the flight state of the other nearby aircrafts. One major point not to miss is that the area is in terms of time, in

The TCAS II uses mode C transducer to determine the vertical separation between the host aircraft and the intruding aircraft, and any error in the information provided means wrong Resolution Advisory issued. This limitation is clearly pronounced since TCAS II cannot know if there is any malfunctioning equipment leading to wrong information being provided. There have been several reports where erroneous TCAS advisory have created conflicts, which never existed in the first place. Additionally, one major limitation is that it issues advisory regarding only vertical separation, when horizontal separation could result in more smooth and gradual maneuver, and also could be difficult to execute vertical maneuver near terrain. Also, the ATC is not automatically information about any advisory issued by TCAS unless the aircraft is within an area covered by Mode S, or an ADB-S monitoring network. Clearly, in such cases, the ATC, being unware of the advisory issued, may direct the aircraft in such a way