Xavion Pitot-Static / GPS / Cabin Altitude fallbacks

As we know, various real aircraft  (including Air France 447 and now two Boeing 737s) have been lost due to simple failure of pitot static or AOA systems.

I spent the last several hours this morning flight-testing an Xavion update that real addresses those issues, using the iLEVEL3 AW.

For years now, Xavion has been a GPS-based backup to the air-data-driven flight instruments in aircraft, but there has been a problem with this: GPS is not really as accurate as air data for altitude! And when flying, we want to be able to track altitude VERY accurately, for reasons that become quite obvious during instrument approaches!

So how do we get the robust BACKUP of GPS with the accurate AIR DATA of pitot-static systems?

Well, enter the iLEVEL3-AW coupled with Xavion on an iPad or iPhone. :-O

Here’s how it works:

The iLEVIL3-AW ( https://shop.levil.com ) has little pitot-static ports that you can hook up to the pitot static system in your airplane… EVEN IF IT IS A CERTIFIED AIRPLANE!! The unit is NORSEE certified, which means that it can be added even to certified planes without per-airplane certification because it is ADDED safety equipment. Now, this little less-than-one-pout box is always measuring the pressure from the pitot and static tubes… AND BROADCASTING THAT INFO BY WIFI!!! Xavion grabs that WIFI broadcast and happily presents the speed and altitude on-screen on your iPad or iPhone, giving you an ultra-modern synthetic vision display right on your iPad or iPhone, driven off the pitot-static system in your possibly-older certified airplane. (Currently allowed for only non-pressurized airplanes).

This alone is amazing, but what if the pitot tube breaks or ices over? Would that cause the speed or altitude in Xavion to indicate zero, with ensuing panic and possible crashes?

WEELLLLLLL, the iLEVIL ALSO has GPS and ADSB and AHRS sensors in it, and they are all ALSO broadcast to Xavion.

So, if Xavion ever notices that the pitot-static inputs have gone to a value far, far different from the GPS-derived values, then Xavion AUTOMATICALLY switches over to the GPS data, and the airspeed and altitude tapes on-screen in Xavion instantly switch from AIR-DATA to GPS! So the system auto-reverts to the next-best sensor, and labels the on-screen tapes accordingly!

Now, I know what you’re thinking: What if we also lose GPS signal after the airplane iced over and took out the pitot-static system?

WEEELLLLL, IF your iPad or iPhone has a PRESSURE SENSOR (which all the new ones do!) then Xavion will AUTOMATICALLY fall back to CABIN ALTITUDE for the altitude tape, and the label at the top of the altitude tape will instantly switch to CABIN to let you know that that is the sensor you are currently flying off of!

Whew!

I just spent the last 2.3 hours testing this in my Evo with the pressurization system turned alternately on and off, and now if only my EARS could recover from all the altitude changes! ;-P