ATC and ADSB

WannFly

WannFly

Final Approach
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Priyo
I posted this question sometime back and the general answer I got is, sometimes ATC sighs in to find the ADSB information, if the plane is on 1200.

Has that changed? See my experience below.

Went to KPIR, winds were favoring 25, so I made the long taxi to 25. Crappy taxi layout.

Just on the take off roll a citation announced 7 miles final for 31. I told him I will extend my upwind, then do a right crosswind departure to NE. As he announced his 4 mile final, another aircraft called and said they are taking off, didn’t announce the aircraft type. The citation on final was little unhappy from the sound of his “no delay” transmission. Anyway, I was on my merry way and tuned to MSP center and said “ MSP center, NxxxxK off Pierre VFR request” , got a reply “ N21K a citation just took off rny 31 and heading your way”

I was squacking 1200, I am glad he called it out, since he didn’t have me in sight, was at my 6 and I had no clue that it was a citation. ADSB finally showed him 1 mile behind me. I turned 30 degrees left to get out of his way. All good, well the citation driver could have announced his aircraft type and intentions while taxing instead of when he did, during the take off roll, but o well.

The question is, was the controller looking at KPIR for whatever reason and found what’s going on? May be he gave a release to the citation that was talking off?

What’s the SOP for controllers these days regarding ADSB targets?
 
one of the citations was VFR. or the controller screwed up. but either way, the controller would have been paying a little bit of attention to the airport because he either Cleared and switched the first citation, or he just released the second one and was waiting for him to tag up. he probably thought your target was the departure and was surprised when you werent. regardless, both citations, in VFR conditions, are required to comply with traffic patterns. The departing aircraft should have probably waited until the arrival landed, but he was possibly concerned about a clearance void time.

As far as ADSb, we can get info on a target pretty easily, including callsign.
 
Even before days of ADSB, controller often look out for "issues" if they have time.

I was flying practice slow flight one day about 5 miles from towered airport. Tower called and asked if i was on frequency then told me a F-18 Hornet was inbound from my direction and i might want to move north a little. Which i did as fast as my 160HP would do !
 
Wrench978 said:
As far as ADSb, we can get info on a target pretty easily, including callsign.
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A couple of weeks ago I was flying a Mooney from Washington State to Arizona. I normally use flight following, but on the VUO-RBL leg I decided not to, though I monitored the Cascade Approach frequency while passing near Eugene, Oregon, at 5500'.

Even though I hadn't made contact with ATC since departing VUO over half an hour earlier, Cascade Approach called me out of the blue by callsign, "November 301 Lima Mike, are you on frequency?" He had to have gotten the callsign from ADS-B.

I acknowledged. He said, "Thank you for monitoring the frequency. Are you landing at Eugene?" I told him no, just passing through to Red Bluff. He gave me a slight heading correction for a few miles to avoid EUG's departures, then when I left his area he thanked me again for monitoring the frequency.

Interestingly, during the 11 hours I've flown this airplane over the last three weeks, its track only occasionally shows up on Flightaware, sometimes for only a few miles over a long trip. On this trip the track ends near Corvallis and my transit near EUG doesn't show at all. It has a Tailbeacon 978 MHz ADS-B transmitter, while airplanes I've flown with a 1090 MHz ADS-B system show up consistently over the entire flight. Later that day I wanted to be sure the Mooney's ADS-B was working, since my ultimate destination was within the PHX Mode-C veil. I asked Oakland Center if they were receiving our ADS-B signal, and they said yes.
 
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On that topic, do the FISK controllers still refer to airplane colors and type, or are they calling out tail numbers based on ADS-B?
 
sarangan said:
On that topic, do the FISK controllers still refer to airplane colors and type, or are they calling out tail numbers based on ADS-B?
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I experienced both. Quiet arrival, ads-b; busy arrival, color and type.
 
I have a related question about transponders. Before ADS-B Mode-C transponders would fire up rather quickly and report back Sqwak and altitude practically right away. But now I have an ADS-B Garmin GTX345. Did you know when switched on it replies nothing until after the internal GPS has fully booted up? No reply back to interrogations if GPS position is not known. Not even Sqwak and altitude only. That just seems wrong to me. As near as I can tell it takes it about 5 min to get it's position and start working. So be better than I was and don't forget to turn that thing on as soon as you fire the engine up. Let it boot up during taxi and run-up.
 
Could be the departing Citation was on an IFR clearance and the controller was expecting him.
 
William Pete Hodges said:
now I have an ADS-B Garmin GTX345. Did you know when switched on it replies nothing until after the internal GPS has fully booted up? … As near as I can tell it takes it about 5 min to get it's position and start working.
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If your 345 GPS takes that long to get a fix on power up, I’d suggest checking that the installer properly hooked up the keepalive power input (a separate wire from the main power input, it needs to go direct to a battery and stay powered 24/7). Without it, the GPS has no stored almanac information to speed up the fix. The other circumstance it might take longer is if it’s been a considerable amount of time since it last was flown/had a fix, in which case the almanac may be expired even if the keepalive is connected.
 
Since I noticed this on a return flight the same day, you are most likely correct. How much power is consumed to keep the unit memory alive? Could it be done with a capacitor for a limited time of say 24-48 hours?

Is there a way for the 345 to respond to interrogations without GPS so that it behaves like a previous generation transponder, and then adds the GPS information when available?

Just asking. This type of information is difficult to find. Thank you for your help.
 
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I've had ZTL call me out as traffic to other people by type (and even N number) when I was squawking 1200 and not talking to them.
 
Pilawt said:
Interestingly, during the 11 hours I've flown this airplane over the last three weeks, its track only occasionally shows up on Flightaware, sometimes for only a few miles over a long trip. On this trip the track ends near Corvallis and my transit near EUG doesn't show at all. It has a Tailbeacon 978 MHz ADS-B transmitter, while airplanes I've flown with a 1090 MHz ADS-B system show up consistently over the entire flight. Later that day I wanted to be sure the Mooney's ADS-B was working, since my ultimate destination was within the PHX Mode-C veil. I asked Oakland Center if they were receiving our ADS-B signal, and they said yes.
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Enthusiasts have ADS-B receivers spread throughout the country that provide their feeds to FligthAware. Most are just 1090ES and some are dual frequency, so the ADS-B coverage for UAT systems such as the TailBeacon is not as complete as it is for 1090ES.
 
I sometimes listen up even when not talking to an approach. If things seem a little busy I’ll call up. I try not to be an impediment to 121 traffic, say with Green Bay approach on a U.P. trip.
 
William Pete Hodges said:
How much power is consumed to keep the unit memory alive? Could it be done with a capacitor for a limited time of say 24-48 hours?
Click to expand...

The stated current draw is max 40 (28V input) or 85 (14V input) microamps. Someone smarter than me will have to do the capacitor math! I just tied mine direct to battery with an inline fuse.

70AB572B-7BE6-483C-AAFE-613489C770CA.jpeg

William Pete Hodges said:
Is there a way for the 345 to respond to interrogations without GPS so that it behaves like a previous generation transponder, and then adds the GPS information when available?
Click to expand...

I don’t see anything in either the install manual or pilot’s guide that indicates the is available. There’s the option to disable the ES ADS-B transmit, if that option is enabled by the installer, but no sign that it’ll operate in a sort of “regular Mode C” state if GPS isn’t available (which seems like it would have been a smart fallback mode, but what do I know?).

One thing I wish it would do is reset to 1200 after a power cycle so I don’t need to remember to reset it after landing!
 
John Collins said:
Enthusiasts have ADS-B receivers spread throughout the country that provide their feeds to FligthAware. Most are just 1090ES and some are dual frequency, so the ADS-B coverage for UAT systems such as the TailBeacon is not as complete as it is for 1090ES.
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This. I have multiple feeders set up for Flightaware/Flightradar24 but they're only listening on 1090. Seeing your post, I'll think about adding the 978MHz radio to my feeders. I set them up a long time ago, well before I was flying.
 
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