Formation flight w/ ADS-B in

[swatson999]

When flying with friends, we often form up (either in close or "loose" formation, depending on who is in the group) for our trips. When doing this, only the lead aircraft should have their transponder on. But, I still get traffic alerts via the ADS-B In box *on the lead aircraft*, even if MY transponder is off (SBY mode).

Any way around this? Or any explanation of why it's happening in the first place (why am I receiving ADS-B traffic info in the first place, if my XPDR is not sending anything out)?

 

[akarmy]

I've had the same experience, but it's very intermittent. I will get like 3 - 4 alerts in a 1 hour of formation. Not sure why it decides that sometimes there is an alert condition but most of the time not.

Agree it would be great if there was a way to deal with it.

 

[dynonsupport]

The whole point of ADS-B is that it's "broadcast" to everyone. While it takes an airplane to wake up a ground station, once one plane does, all planes can see traffic in that area. That's how all the portables like Stratus can advertise having "some" ADS-B traffic. So we end up seeing that lead plane, we know where you are, and thus generate an alert. The lead plane doesn't have this issue because all the trail planes are not transmitting ADS-B out so they're invisible.

You can go into your audio setup and turn off the audio for TRAFFIC. Or you could pull the breaker for your ADS-B box if you have one. There isn't a quick software setting in SkyView to handle this.

You likely have alerts only come on rarely because we generate an alert only when you go from not a threat to having a threat. When you're close it's generally always a threat. It's only when you turn, break, or something else that the system will see you diverging enough to say you aren't a threat that you reset the alert and get it again when you re-join. Radar especially is not perfect so this could happen all by itself now and then even if you are straight and level, if it gets enough lag to think your lead is far away from you and then snaps back then next time you get swept.

 

[swatson999]

Think you could add to your list of requested features a "suppress alerts" capability (which would rest on reboot or change of state of XPDR)?

 

[lgabriel]

+1 to Steve's solution. It'd be nice to suppress alerts but still be able to see the traffic picture.

Even if you're not doing formation, chances are pretty good you wouldn't want alerts after selecting SBY.