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ADS-B Collision Avoidance


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How should one respond to ADS-B traffic advisories. I’m used to flying with TCAS which will issue a resolution advisory to avoid conflicting traffic. How should you resolve a conflict with other traffic using ADS-B? If VFR I imagine it’s still see and avoid? If IFR separation is still controllers responsibility. Under what circumstances will I get an aural warning concerning traffic?

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I have TCAS at work, as well.  Getting used to ADSB traffic warnings will take some adjustment, since all you'll receive is the equivalent of a TA, and of course you'll never get the RA.

First and foremost, you'll have to configure the parameters that will result in a traffic alert on your iPad or portable display.  How much/how soon of a warning you receive is based upon how program the unit based upon how much distraction you want and how busy your normal airspace is.

When I get a traffic alert (through my headset- highly recommended), I begin scanning for traffic.  My Garmin shows a trend vector, so that shows which direction the opposing traffic is moving.  I simply steer away from that other traffic's path and- most importantly- I ensure my altitude is more than 300' different from theirs.  I have never received a traffic alert while IFR, but I fly around a fairly quiet area, all things considered.

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How should one respond to ADS-B traffic advisories. I’m used to flying with TCAS which will issue a resolution advisory to avoid conflicting traffic. How should you resolve a conflict with other traffic using ADS-B? If VFR I imagine it’s still see and avoid? If IFR separation is still controllers responsibility. Under what circumstances will I get an aural warning concerning traffic?



As Andy pointed out, you’ll never get the directional guidance on what to do. But depending on which aural warning system you have, it will give you a pretty good idea where the traffic is relative to your position.

I have the Lynx ATAS system which does a really good job of calling out REAL traffic conflicts. It will tell you distance, whether is high or low from your altitude and if the conflict is climbing, descending or level.

If you watch my video here, at around 2:00 I already have seen the traffic on my ADS-B display and was looking for it. That is one nice advantage you gain with TIS-B, the situational awareness of where planes are relative to you. Add in the aural warning, you have a pretty good idea of what direction the risk is and an idea of where to go to get away from it. At 3:08, you can hear the ATAS point out the traffic conflict. I already was planning on my avoidance strategy.



One thing I do in my plane is set the various traffic display criteria differently. On my Aspens, I keep the traffic completely unfiltered. I do this because if I am transversing the approach corridor for Philly, I want to see those descending jets heading into Philly. Obviously IFR, ATC is keeping an eye out for me, but it is reassuring that I can see where the traffic is when I am VFR. Nothing like seeing an airliner dropping in from above or a couple C130s from Dover doing an oil burner route crossing in front of me.

On my Lynx unit, I set the traffic display to a 2 nm range and set it to filtered (normal mode). This will filter out everything that is way below or above me and only show traffic close enough to me to become a conflict.

I also can vouch for the TAS add-on to my Lynx unit. I thought it would become less important as ADS-B was implemented. But there are areas still on the east coast where I am seeing low flying transponder only equipped planes that TIS-B hasn’t picked up but my TAS unit has.


Sent from my iPad using Tapatalk Pro
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You can take them with a bit of a grain of salt.  Those aircraft on your display are NOT shown to scale.  Still, it is a very nice thing to know what's around you.  No excuse to not keep those eyeballs outside, lots of aircraft running around with no transponders that won't show up on the box.

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On a TCAS II system if both aircraft are TCAS equipped the RA issued is opposite maneuvers for each aircraft one is told to climb and the other to descend when they are close to the same altitude. The TCAS software takes into consideration altitude and climb performance to determine which aircraft is to climb.

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I set my alert parameters pretty liberally and keep the tablet / portable showing the traffic in my scan.  So far I’ve been able to get a sense of what the traffic is doing enough to vector myself around (using 3 mi anticipated sep) as if I’m a really untalented air traffic controller. Primary is head up and out the window however.  The adsb has really been helpful avoiding surprises out the window though.  

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TCAS is great until you get crossing traffic above you and below you at the same time and 300' above and below at high speed

Then the TCAS goes nuts

Night B757 Beatty VOR and crossing traffic were French Mirage jets that had fallen out the box going   back into Area 51. 

Visually close on the iPad is a long way off by eyeball with ADSB. At least for me.

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The coolest part of having ADSB dots on the screen...

When ATC points out traffic to you...

It is so easy to find on the 2D screen, while you are looking out the window...

Having it on the screen gives you a chance of looking in the right direction outside...

PP thoughts only, not a CFI....

Best regards,

-a-

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