ADS-B receivers are unquestionably the hottest iPad accessory right now. These all-in-one devices stream GPS, subscription-free weather, traffic and sometimes even backup attitude information to your iPad, changing it from a static chart viewer to an interactive in-flight tool.

Stratus 1S and 2S ADS-B receivers

ADS-B receivers turn the iPad into an interactive in-flight tool.

They are also the source of a common question we get at iPad Pilot News lately: “which ADS-B receiver should I buy?” With all the options (over a dozen at last count), it’s easy to get confused. In previous articles, we’ve considered a sample flight profile and shared what you can expect to see in flight. But some readers have asked for more details–and our opinion. Here, we’ll try to offer a practical guide to choosing the right ADS-B receiver. We will focus on the most popular models.

Choose the app first

The first tip is easy: choose the app you prefer first, then choose an ADS-B receiver that works with that app. Some pilots get this backwards, chasing hardware around and switching between apps. That just leads to confusion and frustration.

As a pilot, you have to live with your aviation app on every flight (and in between them) whether you use an ADS-B receiver or not. Make sure your app is one you understand and feel comfortable using. Whether it’s ForeFlight, Garmin Pilot, WingX, FlyQ or something else doesn’t matter–the right app is the one that works for you and your flying. Try them all (they offer free trials so you can couch fly them) and become truly proficient with the one you select. After picking your app, then it’s easier to choose the right ADS-B option. Because of the deep integration required between app and accessory, many ADS-B receivers are app-specific:

  • ForeFlight: Stratus 1S or Stratus 2S
  • Garmin: GDL 39 or GDL 39 3D
  • WingX and FlyQ: Dual XGPS 170, iLevil, Sagetech Clarity or Sagetech Clarity SV

Don’t misunderstand us: there are differences between the various ADS-B receivers. But these differences pale in comparison to the apps. You have to start here.

Using a Garmin portable GPS?

Garmin 796 and GDL 39

Garmin’s GDL 39 3D can connect to the aera 796 portable GPS.

If you fly with a Garmin 796, 696 or aera 500 series GPS, there is an additional consideration. The GDL 39 and GDL 39 3D can both feed information to a portable GPS, in addition to your iPad. This is a nice way to get extra utility out of an older GPS or to have a full-featured backup navigator in the cockpit.

For the 796, this connection is wireless via Bluetooth. For the other models, it requires an adapter cable. Also note that the latest update to the Garmin 796/795 software allows you to display full pitch and roll information from the GDL 39 3D’s built-in Attitude Heading Reference System (AHRS). This makes the 796/795 a no-compromise display unit for the GDLs.

If you don’t have one of these devices, this feature won’t matter. If you have a Garmin GPS but you use another app, is it worth switching to take advantage of this? Only you can answer that question, but ask yourself which device would be primary: iPad or Garmin.

Comparing specs

Once you’ve settled on an app and considered the Garmin option, it’s time to choose a specific ADS-B receiver. This is where it makes sense to compare specs, but it’s worth noting that every receiver on the market offers the two key features: GPS and subscription-free weather. These are the things you’ll use most often, and every unit includes them. That means there isn’t really a bad option.

Beyond these basics, there are two other features to consider: traffic and attitude. While all portable ADS-B receivers are limited in terms of how much traffic they display (see this article to learn why), dual band ADS-B receivers generally pick up more traffic. So if traffic is an important feature, consider a dual band receiver. One more note on traffic: if you’ve already equipped with ADS-B Out in your panel, single band is all you need.

  • Single band ADS-B traffic: Stratus 1S, Dual XGPS 170
  • Dual band ADS-B traffic: Stratus 2S, all GDL 39s, Clarity, Clarity SV
WingX synthetic vision

Some ADS-B receivers include an AHRS for backup attitude or synthetic vision.

Newer models offer the option of a built-in AHRS to deliver backup attitude information or synthetic vision to your iPad. This is not even close to a primary instrument, but in a worst case scenario we would not hesitate to use it. For a VFR pilot, it may be overkill and you can save a lot of money by choosing a non-AHRS model, but we still think there’s value in it for situational awareness. For an IFR pilot, it’s a great insurance policy.

  • No AHRS: Stratus 1S, GDL 39, Dual XGPS 170, Clarity
  • With AHRS: Stratus 2S, GDL 39 3D, Clarity SV, iLevil

Other considerations

Battery life is another feature to think about. For a homebuilder wiring in an ADS-B receiver, or for a pilot who plans to keep his receiver plugged into the cigarette lighter, a built-in battery may not be necessary. For a renter or a pilot who prefers fewer wires, a built-in battery is an essential feature. We also think it has great value as a backup.

  • No battery: GDL 39, GDL 39 3D
  • With battery: Stratus 1S/Stratus 2S (8 hours), GDL 39/GDL 39 3D with battery pack (3 hours), Dual XGPS 170 (5 hours), Clarity/Clarity SV (6-8 hours)

There are also some additional features beyond the basic weather/GPS/traffic/attitude set. Some newer models, like the Stratus 2S, include automatic flight data recorders so you can store your flights and replay them in apps like CloudAhoy or Google Earth. The iLevil Sport, on the other hand, has a built-in solar panel on top to extend the battery life.

Finally, while most pilots spend a lot of time debating single vs. dual band or AHRS vs. no AHRS, we think too little time is spent on “softer” features. These include ease of use, reliability and customer support. Such features aren’t easily compared in a chart, but they impact your flying in a significant way. Consider how well-integrated the receiver is with the app, how easy to use the entire system is and what customers are saying about support. You can learn a lot reading customer reviews online.

One feature that doesn’t matter much is reception. Every ADS-B receiver we’ve flown with has perfectly good reception for normal operations, and with the ADS-B network now complete, this is less of a problem than ever. Remember, one tower is enough in most cases–we usually see 3-10 towers at cruise altitude.

Comparison chart

To help you compare features side-by-side, we’ve compiled this chart to show most of the popular options. Click on the image for a larger image.

Final thoughts

Don’t make this decision harder than it needs to be. In its most basic form, we suggest a two step process. First choose your app, then choose whether you want “VFR features” or “IFR features.” The big difference between VFR and IFR would include a built-in AHRS. In most cases, you will have a decision after answering those questions.

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