X-Avionics has temporarily suspended sales to new customers.

We have found that data, aviation development, and liability insurance costs are not consistent with App Store one-time purchase pricing.

For this reason, we have removed Xavion from the App Store and are not currently accepting any new orders.

HOWEVER, we have recently uploaded a NEW version of Xavion to the Apple Store, and it is pending approval by Apple now! (This process normally takes a few weeks).

This version of Xavion (1.38) has a huge number of improvements that make it the finest and most refined piece of software I have ever written. This version will be available at a MONTHLY charge that is not too different from other aviation Apps that require monthly database updates.

As well, I have coded this version of Xavion to give about 5 months of FREE service to all EXISTING customers, so that all EXISTING customers that paid $99 will get a value that exceeds what they have paid. Subscribe to the newsletter on the lower-right of this page to get announcements from me on when Xavion 1.38 is approved by Apple.

Contact me at austin@xavion.com if desired.

Now, if you like, here are some specifics on the latest new features and refinements for Xavion 1.38, which is uploaded to Apple and pending their approval now:



Enter your glide ratio in the LANDING configuration now, as requested in the setup screen.

This is used for Xavion to predict your deceleration in the final phase of the approach, which it can then use to set up your approach more accurately.

Planes like the Questair Venture and Lancair Evolution have incredibly slick bodies with absurdly draggy gear will drop like rocks with power off and gear down.

Xavion now plans for this with appropriate deceleration based on the LANDING configuration glide data mentioned above.


Much more testing and refinement in hi-wind conditions, with 40-knot surface winds routinely tested in the simulator.

Which leads us to… We now adjust our best glide speed for the wind conditions!

Historically, when we fly as our instructors taught us, we just memorized the “best glide speed” for our airplane and used it.

You enter this number into the setup page in Xavion.

But, now, we consider the winds to see when we can stretch the glide by going OFF of the published glide speed!

With a tailwind, we fly a little slower (close to our “minimum sink” speed).

With a headwind, we fly a little faster (to get our of that headwind ASAP).

You can see the wind-corrected best-glide speed as a “VG” tick on the airspeed indicator.

So, if flying with a headwind, you will notice it shows you a little higher best glide speed.

If flying with a tailwind, you will notice it shows you a little lower best glide speed.

This is yet another area where Xavion shows that we can re-think the way we fly airplanes! The concept of “just always go to best glide speed” is really replaced by far better math now!

(But, the user-friendliness remains… all you need to do is aim through hoops, or fly the little “VG” tickmark on the airspeed indicator!)

We now have more approach options, now considering more final-approach lengths to help optimize the path for the ideal glideslope.

We now CLIMB at 6 degrees after the engine failure if we are carrying more speed than we need!

This conserves energy by rapidly getting us down to an ideal speed, and gaining some altitude to help us find more approach options!

Also, by lowering our speed to a nominal glide speed quickly, our speed is low enough to take a pretty QUICK turn to to the airport… not a really long, wide turn that would happen at higher speeds!

We now have the green gate at 200 feet AGL instead of 400 feet!

With many hundreds more tests run, both in the sim and in real airplanes, we are lowering the green gate to the standard ILS decision height.

As well, we have historically checked for terrain and obstacle clearance down to the “green gate”, the final point at which you are expected to take over aircraft control.

Now, we check for terrain and obstacle clearance all the way to the planned touchdown.

We now spend more CPU on trying NEW approach solutions, and less on keeping the CURRENT best approach updated.

This results in your current best approach being up to one second old (which should not present any problems!) but comes up with new solutions more rapidly.

We now have better roll-out planning: We plan hoops to center the landing roll-out perfectly in the center of the runway (longitudinally),

or go halfway between that and touching down right on the threshold, or halfway between that and stopping right at the far threshold.

(The latter two cases being useful if you are close to the runway and uncomfortably high or low).

Warnings and 1,000 extra feet of altitude are provided to circle-to-land when using runway data that is not continuously updated and checked by local aviation authorities.

(Some runway data is constantly updated by various local aviation authorities, some not. We provide now provide a warning and altitude buffer in the cases where the runway data is NOT provided or updated).

Approach hoops are now designed to look at gust and shear to base the airport scoring on the WORST-CASE wind you could have based on the gust and shear reported.

Thousands more simulations have been run in X-Plane to test Xavion and tune the algorithms for maximum safety, and hundreds of approaches have been observed and dozens more flown in real airplanes to further verify the results.


When the hoops are engaged, the current safety margin for that approach is shown.

The safety margin is determined to be the the part of the approach for which there is the LEAST margin for error, while considering weather, wind, gliding distance, and runway length.

The part of the approach that is the most concerning to Xavion (the length of the runway or distance to the airport, for example) is shown to you when you hit the emergency button to start an approach.


Better airport and chart data-downloading protocols, so Xavion will automatically re-download data if needed.

Your region-selection preferences are always saved, so all of the right maps are checked for expiration the next time you boot the App!

No more warning of expired Sectional charts if you have an in-date Low-Enroute charts up, and vice-versa.

So, now, Xavion only warns you of expirations of charts that you are actually looking at, to avoid confusion.


Better METAR-scanning (we now are able to parse some more slightly non-standard METAR reports)

We now have TAFs for weather as well as METARs!

So, touch an airport you are going to, and if it has a TAF, then it will show it.

Nice to have a weather prediction for the future.

All obstacles underneath you are now shown in profile view… even if you are so high above them that they should not be relevant to your flight!

This is just for an added level of awareness.

Longer trips can be shown on the map now for long-range planning… far beyond the close-in emergency scenarios we normally use.

We now have room at the top of the weight and balance screen to show aircraft weight numerically even at gross-weight conditions… and there are many other small graphical improvements like this as well.

Sharks-teeth removed from the display.

They cluttered things a little more than we needed, and we can see on the MAP how far we can glide, so I decided that the need for the sharks-teeth was lower than the drawback from having them.


In many cases in Xavion, we start with the best source we can get, and fall back to backup sources if the primaries fail.

If we do not have government-updated runway-endpoint data for a given airport, then we fall back to old DAFIF runway-endpoint data.

If we do not have DAFIF runway-endpoint data for a given airport, then we fall back to circling approaches to the airport.

If we do not have GPS for our location, then we fall back to deduced reckoning for the location.

If we do not have GPS to help with attitude, then we fall back to the iPads or iPhones internal gyros and accelerometers.

If we do not have a METAR for an airport that we are trying to land at, then we fall back to a terminal area forecast for that airport!

If we do not have a terminal area forecast for that airport, then we fall back to the lowest-available altitude at the closest-available winds-aloft reporting-point for the best wind estimate we can get!

So, as always, we take all the data we can get, falling back to backup data if the primary data is not available!

So, this is a back-up App that falls back to backup data in the event that primary data is not available!

Everything I coded in Xavion is based on a lot of stuff going wrong… and having Xavion always overcome various system failures to guide you back onto a newly-planned course for a successful landing.