Garmin traffic
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I recently moved a friend’s airplane from the Nashville area to Minnesota. Not just a normal, been-around-the-block-a-few-years airplane, but a brand new airplane with all the latest Garmin glass cockpit electronics and technology. What a beautiful plane!

When I was doing the pre-flight and confirming the setup, I noted that there was no ADS-B In screen. Further investigation, even getting on the phone with the Garmin support reps, determined that the aircraft—ordered, bought and paid for with ADS-B Out and In—only had the Out configuration.

Panel with screens

No ADS-B In – does it matter?

Now for many that would be no big deal. A VFR cross-country flight with a fully capable (if minimum requirements) airplane, with or without ADS-B In—no big deal. But (and there is always a but, isn’t there?) I had not flown an aircraft without ADS-B Out and In over the last five years. So even though I was not crossing any major airspace on my trip once I departed the Nashville Class C, I would not be able to rely on an ADS-B In instrument readout for adjacent traffic awareness.

My comfort level over the last five years for knowing what else was out there had become very dependent upon the In screen on my PFD. For this trip, good old fashioned scanning was my only visual clue, although I was utilizing ATC flight following.

Of course, instrument-based reliance is only relevant if the adjacent traffic is ADS-B equipped (or Mode C and rebroadcast from ADS-B ground stations). The reality for my flight plan was that my route covered areas where, for the most part, no one was required to have ADS-B. I’d be under 10,000 feet so Class E airspace issues were relevant only if I was flying over any Class C or B airfields—and I was not. I’d be far outside the Mode C areas for any Class B airfields, so my route would be in non-controlled Class G airspace except when transiting the Class E making fuel stops. And I was doing those stops only at Class G airfields and ADS-B Out is not required for those transitions.

So even if I had the In capability, would that really tell me the potential risks for other aircraft? After all, everybody has ADS-B by now, don’t they? I did some checking at the FAA website: the results might surprise you.

The requirements for ADS-B are fairly well set: if you fly within Mode C, Class B or C, above Class B or C airspace up to 10,000 feet, or at altitudes of 10,000 feet or more, the airplane must have an operable ADS-B Out system. But if you do not fly in those areas, you are not required to have ADS-B. If you have an In capability, in addition to ADS-B Out telling the network where you are, you can see the local traffic for Out-equipped aircraft. Any traffic using a Mode C transponder, if linked to the ground system and radar, will also show on the In screen as well as the graphical weather updates.

Fortunately, most GA airplanes are now equipped with ADS-B. As of  June 1, 2022, the FAA data indicates 103,556 fixed wing GA aircraft are ADS-B compliant, out of roughly 161,000 active airplanes. But these numbers do not include some 35,000+ airplanes in the Experimental or non-certified LSA categories. And if many of these aircraft are only operated in the non-required airspace areas, chances are a sizable percentage do not have an Out capability.

As to my mission—fly a brand-new airplane (which was really cool) to my friend in Minnesota and don’t hurt the plane in any way—it went well. The flight up from Nashville had some weather challenges, with stronger than expected headwinds requiring an additional refueling stop. And I was constantly in scan-mode, more than I probably would have been in my own Out and In equipped aircraft, looking for other traffic throughout the flight.

When I reached my destination airport, a non-towered, cross-runway airfield which is also home to a major university aviation program, the visual scanning part did get a bit busy. Easily 6-10 students were doing pattern work or practicing ILS approaches. I could hear them on the radio, I could sometimes see most of them, but I could not get that instant image on my PFD of the bogey locations relative to me that I was used to. No worries—I did what I was trained to do before ADS-B was required, made my local traffic radio calls, slipped into the pattern, and landed my friend’s plane at its new home. Mission accomplished.

Garmin traffic

Does this screen lull you into complacency?

I did come away from the flight and flight planning with a few items to think through. Had I become too reliant—and presumptive—that my ADS-B In display was telling me all I needed to know about surrounding traffic? Had this reliance actually made me less safe as a pilot when I was in airspace where ADS-B was not required? Would I now, upon reflecting on the first two questions, become a more aware pilot in all airspace than I had been?

I also wondered about the risk to non-equipped pilots, whether flying without ADS-B In, or without ADS-B at all. In the old days before 2020, everyone was—or was supposed to be—looking for each other. If pilots used to flying with ADS-B In have a bit of complacency and over-reliance on their displays, are they looking as diligently for the other guys as the other guys are probably looking for them?

I do have a renewed appreciation for the benefits of ADS-B In. When you do not have a capability you are used to, you realize why you want that capability. Whether or not all of the bogeys in my area were ADS-B compliant, wherever I am flying, at least I knew where the ADS-B equipped folks were. Having that information, in my estimation (and according to the research) does make me a safer pilot, with the recognition of non-equipped aircraft. Many times I’ve been given a traffic alert by ATC of converging traffic and I cannot think of a single instance where the other aircraft did not show up on my ADS-B In screen, whether I got eyes on them or not. My awareness odds are a lot better as a result, and I like that.

Wherever we are flying outside of the ADS-B mandatory areas, we cannot discount that percentage of non-equipped GA aircraft, and who knows what percentage of Experimental and non-certified LSAs; they might not show up on traffic screen. But it’s a big sky, and vigilance with scanning for traffic remains the answer for any VFR flying conditions—not relying solely on the ADS-B In display.

Mike Hackney
Latest posts by Mike Hackney (see all)
20 replies
  1. Steve Green
    Steve Green says:

    Mike, great discussion of this. When I transitioned to the 737, the schoolhouse made a big deal out of the full time autothrottle. So I cooperated and graduated, so-to-speak, and started leaving the autothrottles engaged all the time (previous jets normally disengaged them on short approach). A few months later, I was dispatched with an inoperative autothrottle. No big deal, I thought…I’ve flow 767’s across the Atlantic without an operating autothrottle. We took off from MIA, made a big left tuen northbound, leveled at the assigned 7000 feet, and the next thing I knew we were doing 290 knots. Just a quiet little reminder of automation dependence.

    Around the same time, I got re-engaged in GA flying, using a club 172 with ADS-B In displayed. One day out over the practice area, I felt like I was literally in a dogfight, twisting this way and that to avoid other traffic at the same altitude. Never saw a single one. I’m still not sure how we survived back in the old days!

  2. Michael Hackney
    Michael Hackney says:


    You are dealing with equipment that has such complexity—yet your point on reliance and complacency really drives home the risks we all take if we become over-dependent. Thank you, and safe flying!

  3. Paul Robichaux
    Paul Robichaux says:

    I’m maybe more surprised that no one at the factory caught the fact that the airplane was missing something important like the missing ADS-B In capability. Makes me wonder what else the acceptance testing might have missed.

  4. Michael Hackney
    Michael Hackney says:

    Steve, I’m pretty sure the owner got all of that reconciled. But I agree it makes you wonder!


  5. Gary Lanthrum
    Gary Lanthrum says:

    Loss of ADS-B in on the panel didn’t mean you couldn’t have the information. I don’t have ADS-B displayed anywhere on my panel but I get that data on my tablet with a portable ADS-B receiver. I do have ADS-B out, so my portable unit for incoming information doesn’t rely on another aircraft to trigger the ground stations. I like havng a portable system for incoming information that I can use with any plane I’m flying. There are cheap portable solutions available if you want the flexibility even if your plane has a plane has a panel mounted solution.

  6. Karl T
    Karl T says:

    “If you have an In capability, in addition to ADS-B Out telling the network where you are, you can see the local traffic for Out-equipped aircraft. Any traffic using a Mode C transponder, if linked to the ground system and radar, will also show on the In screen as well as the graphical weather updates.”
    Mike – nice article & I share you’re apprehension not having ADSB-IN dispays. Your statement above is not quite correct. If you have a dual-band ADSB-IN receiver (GDL88 etc, or portable receivers), you can pick up ALL ADSB-Out aircraft whether on Mode C or UAT bands directly, not necessarily thru Ground stations . That’s really the only way to display all those equipped targets. Non-equipped Cubs etc are the birds you have to see with your eyeballs.

    I had an early NavWorx ADSB UAT-In-Out from Dec 2011 until it died last year & installed Garmin GDL88 dual in & watched the network of ground stations build out & become more capable. I realized early on that without Dual-Band receiver onboard, I was missing out everything not sent to me by ADSB ground stations, more often than not at airports below ADSB ground station coverage. That’s the real issue of relying on ADSB ground stations to display traffic at low altitudes.

  7. Ron Kline
    Ron Kline says:

    Don’t forget that even when flying in mandatory ADSB
    Areas there are airplanes not equipped with electrical systems that can be flying there. So you still need to be vigilant in looking out the window.

  8. Roy Adams, Jr. Ph.D.
    Roy Adams, Jr. Ph.D. says:

    Mike, You mean what you learned in the Army, “Big sky, little plane,” was not relevant? Roy

    • Michael Hackney
      Michael Hackney says:

      Well, Colonel of Infantry Dr. Adams, I think we called it ‘Big Sky-Little Bullet’ when telling the Air to Mud folks to help us—but these other folks are usually visible when they get close. Maybe unavoidable by the time you see them, but visible.

  9. Lee Dalton
    Lee Dalton says:

    I fly one of those Experimentals with no requirement for ANY electronics.
    Although most of us who fly Powered Parachutes remain at relatively low altitude AGL, I really worry that too many pilots of more “sophisticated” equipment may be spending far too much time playing video games on their glass panels and rarely take a look out the window.

    I haven’t had any close calls.
    But it’s something that does bother me.

    • Michael Hackney
      Michael Hackney says:

      Lee, great points. You’re perspective is quite valid. I see that as the beauty of flying—so many personal options of vehicles that have a great range of capabilities.


  10. Erwin
    Erwin says:

    Unlike the author’s experience, I once had two Mooney’s flying in formation that crossed perpendicular to my path within about a quarter mile, same altitude. They did not appear to have adsb out since I didn’t see them on my EFB display (like all other traffic that afternoon). Fortunately, I was on VFR flight following and ATC gave me a “turn to 180 immediately” instruction! He asked if I had the traffic in site about 30 seconds prior, but I could not see them. They crossed directly in front of me just as I banked south. Thank goodness I was on FF, and ATC had my back! I was sure to thank ATC (Great Lakes in MI) afterwards.

  11. Mark
    Mark says:

    Mike, good points, but “Wherever we are flying outside of the ADS-B mandatory areas, we cannot discount that percentage of non-equipped GA aircraft” isn’t a great comment. Because you can be INSIDE the areas and be exempt. People in Seattle for instance, are thinking that the ADS-B is required to fly under the Class B shelf. It isn’t – that’s in the regs – if you have a no engine driven electrical from the factory onwards. In the past month I’ve two misses and in both cases, the first thing the pilot asked was if I was using ADS-B. That was outside the mode C veil. That is, they expected it. That all traffic was on their screen. I have to explain the exemption for classic airplanes that you hand prop. Things are less safe in some situations. We have too many video game pilots who don’t know VFR rules.

  12. Michael Hackney
    Michael Hackney says:


    Yet another reason not to be complacent that the only bogies out there are the ones that show on the ‘In’ screen.

    Thank you.

  13. Jack Ellis
    Jack Ellis says:

    I’m equipped, I know the rules, and I look out the window. Lately I’ve been keeping score of the number of small airplanes reported to be within two miles that I can spot. The answer is disappointingly low. Maybe the eye tests are wrong but I think not. Unless someone is calling out traffic for me, it’s pretty difficult to spot anything smaller than a jet unless it’s practically on top of you.

    • Michael Hackney
      Michael Hackney says:

      Jack, I know the feeling. I did a little over 5 hours today with half at 6,500 and the other at 9,500. Admittedly hazy conditions. I think I was about 60% of the small planes indicated for eyes on, especially those 3-4,000 feet below. It isn’t easy.

  14. Peter N. Steinmetz
    Peter N. Steinmetz says:

    My understanding was that while ADS-B has improved safety of flight, that is mostly because of the effects of having the GPS so you know where you and the terrain are and having the weather. Not due to a decrease in mid-air collisions. Those are so rare measuring a decrease reliably is hard.


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