Story ID: 095
Flight Test: Garmin D2 Air Smartwatch
By: Matt Thurber
Caption: Garmin's D2 Air smartwatch packs a lot of features into a more reasonably priced device with an Amoled touchscreen.
Word Count: 1013
Garmin has been manufacturing various types of smartwatches for a while, many of which target the sports and activity market, and naturally aviation watches are part of that mix. Until it unveiled the new D2 Air last September, Garmin’s options for pilots were limited to the more expensive D2 Delta series, although prices have dropped since the D2 Air was released.
With the D2 Air Garmin now offers pilots a dedicated aviation watch at the lower price of $499 and without all the features of the more expensive Delta series (currently ranging from $749 to $1,099). If you can live without the extra Delta features, then then the Air might be the Garmin watch you’ve been waiting for.
What sets the D2 Air apart is that it is Garmin’s first touchscreen aviation watch, with a bezel size of 42.2 mm, a weight of just 46.3 grams, and a damage-resistant Amoled display made of Corning Gorilla Glass 3 with 390x390 pixel resolution.
The advantages of the D2 Air’s higher-resolution touchscreen are immediately apparent. The Delta series watches have five buttons, and the learning curve is high because these watches can do so much, including using the D2 Delta as a GPS position source for the Garmin Pilot app. It takes a while to learn what each button does and to navigate the various functions. The Deltas can also connect wirelessly with Garmin avionics, including the GTN 650/750 panel-mount navigators, for flight plan transfer and receiving GPS position and other information. In addition to not providing a GPS feed to Garmin Pilot, other features that the D2 Air doesn’t have include Virb camera control, moving-map navigation and Nexrad on the moving map, and Garmin Connext capability. The navigation display on the D2 Air replicates a horizontal situation indicator layout.
While the D2 Air gives up some functionality, it’s well worth it, in my opinion, given the lower price and all the features that it offers. 
Chief among these is the pulse oximeter, which previously was available only on the D2 Delta PX (around $1,099). This gives a reading of oxygen saturation levels, handy for pilots flying in unpressurized aircraft at higher altitudes but also for pilots who might have compromised lung function and need regular tracking of oxygen levels. One of the most useful features of the D2 Air smartwatch is the oxygen saturation (SPO2) display.
As I did when I reviewed the D2 Delta PX, I compared the D2 Air’s oxygen saturation levels with a finger pulse oximeter. Generally, I found that the Garmin watch pulse-ox readings are lower than with the finger-type oximeter, but it’s still helpful to see the baseline reading and observe any worsening trends. 
During an airline flight, at a cabin altitude of 6,000 feet, the D2 Air read 88 percent, while the finger oximeter read 94. At 7,400 feet cabin altitude, however, both read the same at 90 percent. During a different flight, at 3,000 feet in the cabin, the Garmin read 92 and the finger unit 95. Other times, however, both the D2 Air and finger oximeter had the same readings.
There are many watch-face choices, including complications, on the D2 Air. My favorite so far, the default watch face, lets me set the watch to Coordinated Universal Time in 24-hour format, shown digitally, while the watch “hands” display the local analog time in a 12-hour format. This is perfect for a pilot and saves having to convert times when viewing weather briefings. I also like the default watch face complications that include weather information for my local airport, with temperature, cloud cover, visibility, and a wind indicator. 
The D2 Air is highly customizable, from the selection of watch controls to changing watch faces and selecting widgets for various functions. The widgets appear by touching and scrolling the watch face. I can dive deeper into airport-specific information with one widget, to view TAFs and airport information such as runway orientation with wind components, runway lengths, airport frequencies, and traffic pattern altitudes. The D2 Air includes an updateable worldwide navigation database with navaids and intersections.
Other useful aviation widgets include a three-axis compass and horizontal situation indicator and altimeter with adjustable barometer setting. You can use the horizontal situation indicator (HSI) to navigate, with a direct-to function to a selected airport or by picking one from a list of nearest airports. Alerts can be set for altitude, speed, time, and distance, and there is a handy fuel timer. The Garmin Pilot app logbook can be synced with postflight information, based on flight tracking by the watch.Garmin's D2 Air smartwatch displays a variety of aviation information.
In addition to all the aviation features, the D2 Air includes many of the Garmin sport activity functions, with workouts, training plans, and more, but not all of the same functions as the D2 Delta series. The D2 Air also has Garmin Pay for contactless payment and music storage for up to 500 songs as well as notifications when connected with a smartphone.
Battery time on the D2 Air is up to five days in smartwatch mode or 10 hours when using GPS and the pulse oximeter. 
Overall, the D2 Air’s simpler two-button and touchscreen interface make this watch much easier to use compared to the D2 Delta. To preserve battery power, the Amoled display doesn’t stay lit all the time, so a wrist-raise is needed to light up the screen. But the wrist-raise doesn’t always work, so sometimes a tap on the screen is necessary to light it up.
Having the pulse oximeter at the $499 price point as well as the aviation-specific features makes the D2 Air more competitive with the Apple Watch 6, which also has a pulse oximeter. Very few app makers offer Apple Watch aviation features, and Garmin has taken the lead in the dedicated aviation watch space.