If you were flying in the military, and were in a hot spot where your aircraft was at risk, you would be flying with your IFF, or Identification, Friend or Foe System on high alert — things are a little different in the civilian market. The IFF System does exactly what the name says: it finds other aircraft within range, and tells you whether they are friendly (i.e., not likely to shoot at you) or NOT friendly.
While IFF is a bit overboard for General Aviation, the idea of that system is used for the most part in our Traffic Collision Avoidance Systems, or TCAS. These systems either passively receive, or actively interrogate other aircraft’s transponder systems, and then present information on where they are.
In case you haven’t been up lately, the skies around our airports continue to become more crowded every day and it shouldn’t be surprising that most accidents happen close to airports. New, affordable aircraft are in production, as well as a plethora of new custom planes (homebuilts/experimentals) that are being constructed and hitting the market. This increase in flight hours means: there are more planes in the air, and that means there is a greater risk of getting into an air-to-air collision while you are flying.
The idea behind TCAS systems is to provide an early warning system for collision avoidance. The TCAS does this by figuring out where other airplanes are, and then either providing you that information in text, or preferably, in a color image. Alarms are sounded as other aircraft approach, allowing you to take evasive action before they can impact your plans for an uneventful flight.
WHEN FLYING WITH TCAS
Take every threat seriously until proven otherwise. It is *never* a good idea to ignore a barking watchdog, since it is trying to tell you that something is closer than it likes. The same thing is true with TCAS alarms — if you receive one, IDENTIFY the threat, VISUALLY CONFIRM it or CHANGE COURSE to avoid a collision.
In our opinion, the visual displays win hands-down over text presentations. In the visual displays, the data is presented in a format your mind can immediately comprehend. This reduces or eliminates the need for the mental gymnastics that you would otherwise have to perform to figure out where the threat plane was compared to your position from text-based units.
All it takes is one little bump in the air to spoil the day for two planes full of pilots and passengers. TCAS systems can provide to you with the warnings that — at the very least — increase your situational awareness and at best save you from a close encounter of the terrestrial kind.