Updated 27 January 2017.
Yesterday, I published an article about what to say to ATC when you have identified traffic on your onboard ADS-B screen. Based on feedback from several air traffic controllers, who all responded similarly, I’m going to change my recommendation.
Previously, I said when ATC points out traffic and you notice the traffic on your ADS-B screen, you may tell ATC, “[Call sign] has the traffic on ADS-B”. I also said, as an alternative, you may substitute “TIS-B” for “ADS-B”. This, as it turns out, was not good advice.
ID-ing Traffic on ADS-B is Irrelevant to ATC Ops
Here’s the truth of the matter. The only thing an air traffic controller cares about is whether or not you spot the traffic through the windscreen of your aircraft. Noting the traffic on your ADS-B set or, if you have it, on your Traffic Collision Avoidance System (TCAS) does not affect ATC operations in any way.
If you spot the traffic through your windscreen, in some circumstances, the controller may apply traffic separation rules based on you maintaining visual contact with the traffic. Visual separation rules cannot be applied under any circumstance if you can’t get eyes on the traffic.
It comes down to this. If ATC calls out traffic to you and you pick it up on ADS-B or TCAS, but you don’t actually see the traffic through your windscreen, the correct and only response is, “Negative contact”. If you see the traffic through the windscreen, your response should be, “Traffic in sight”. Telling the controller you have ID-ed the traffic on ADS-B or on TCAS is irrelevant and unnecessary.
Then Is There Any Value in TIS-B?
The real value in the Traffic Information Service component in ADS-B is it helps you build situational awareness of traffic in your area. It may also help you spot traffic when ATC calls it out to you. TIS-B may even help you spot traffic when the controller is too busy to point it out.
Perhaps someday the FAA will develop new ATC procedures based on your ability to ID traffic on your ADS-B set. That day has not yet arrived. Until it does, the only two standard and useful responses to a traffic call out from ATC are “Traffic in sight” or “Negative contact”.
Questions? Comments? Write to me below in the comments section, or send an email directly to Jeff@ATCcommunication.com.