Monthly Archives:February 2018


New Release With AHRS For ForeFlight

Synthetic vision display.

TL;DR – A new FlightBox update is available that adds AHRS support for ForeFlight and GPS NMEA output over RS232.

Introducing v1.4r4

Welcome to the middle of winter. Things have been rather quiet for the past couple of months, which has allowed us to spend some time heads-down on new features and functions. First among those is AHRS support for ForeFlight*. This has been the number one request since we rolled out the original AHRS support back in March of last year.

The update is available for download from our site or for installation using the FlightBox Utility app. New systems ordered after February 14 will ship with 1.4r4 installed. The code has seen quite a bit of testing from the Stratux community, so it should be smooth sailing under most circumstances.

A few notes on the FF AHRS feature:

Web Interface – To get to the FlightBox web interface, you normally open a web browser and go to Because of changes in the update this might not work in some cases (please see below for geeky details). If you update to the latest version and cannot get to the web interface on, try accessing it on If that doesn’t work for you, go into your computer’s (or mobile device’s) network configuration and use the “Renew Lease” function to get a new IP address. (Or just reboot it – that will do the same thing.)

Fully Automatic, Mostly – Once you’ve installed the update you should be able to fire up ForeFlight, select the PFD view, and within a few seconds you’ll see the attitude display lock in. If the display is not level, make sure you have the level-point set from the “GPS / AHRS” page of the FlightBox web interface before you try adjusting the level point in ForeFlight. You may have to restart the ForeFlight to get it to detect the AHRS data.

Requirements – You must have the AHRS hardware installed and configured for this to work. You also must have a ForeFlight subscription that includes synthetic vision to be able to use their synthetic vision feature.

Somewhat Sensitive – The ForeFlight display is somewhat more sensitive than other apps and can bounce a bit. This is in part an artifact of the way we integrate with it. The better the alignment of the FlightBox with the aircraft, and the more secure the mount, the better your results will be.

Apps – This may break the Android and iOS utility apps. To make the AHRS data visible to ForeFlight we had to make some changes to the network addressing structure we use (again, please see the Geeky Details section below if you’re geeky and care about the details). As a result of this, the utility apps will need some updates. If you can’t get the app to connect, please use the web interface.

Other New Stuff

v1.4r4 also adds another new feature: NMEA output. NMEA output lets FlightBox share GPS data with other device over an RS-232 link. The standard GPS mode outputs the current location, ground speed, ground track, and altitude data. (Those would be the $GPRMC and $GPGGA sentences.) All kinds of aviation gadgets can make use of GPS information. Autopilots use it to follow a ground track. ELTs use it to send your position. Fuel computers use it to determine your range.

GPS mode is a great enhancement on its own, but the really interesting feature is NAV mode. In NAV mode, the FlightBox outputs the active waypoint and course deviation information that autopilots use to steer a course. (The $GPRMB and $GPAPB sentences). The steering algorithm in FlightBox can even intercept course lines and anticipate turns – the “roll steering” or “GPSS” feature that is usually only found in high-end navigators.

The kicker with NAV mode is that there’s no standard method for EFB apps to send the flight plan data to FlightBox, so we’ve developed a very simple data exchange format that we’re hoping to get our EFB friends to implement. If you would like for your favorite EFB app vendor to support NAV integration with FlightBox, please send them an email asking them to check out our Integration Guide.

To use the NMEA output, you’ll need an NMEA serial adapter cable. To install it we recommend using a small unpowered USB hub, as this makes connecting it much easier. (The other option is to perform surgery on your FlightBox case to get at the open USB port.) Note that the serial adapter requires the remote GPS – it is not compatible with the internal GPS.

From the lawyers: Please be aware that connections to required, installed systems in a certified aircraft generally require either an STC or a field approval. In some rare cases approval may be available from the manufacturer of the aircraft or certified system. Do not connect FlightBox to a certified system in a certificated aircraft without appropriate approval. Doing so will invalidate the airworthiness of your aircraft.

Getting The Update

The new release is currently available through all of the regular update channels:

This is a larger update and takes a bit longer than most to install. Give your FlightBox at least two minutes to complete the update process.

AHRS Upgrade Kits

If you’ve been holding off on adding the AHRS hardware, you can order the upgrade kit here. It’s only $100 and includes everything you need to add AHRS capabilities to your FlightBox. Please note that your FlightBox must have a GPS for the AHRS features to work. If you don’t have a GPS, you can add either an internal or remote for $35.

Geeky Details

WARNING! If you are not a computer / networking geek, please don’t read this. It contains more techno-babble than a StarTrek marathon. You have been warned.

The new release changes the range of IP addresses that the DHCP server on FlightBox uses. We previously served addresses in the 192.16.10.x range. In order for ForeFlight to recognize the data we are sending, we had to change the source to so we’re serving addresses in that range.

To make the transition as seamless as possible, the FlightBox adds an alias address of to the Wifi interface. If you connect to it from a device that only has Wifi enabled, or which makes the Wifi connection the primary connection, you should have no problem getting to the system on the alias address. However, if your device has multiple interfaces, including one which is prioritized above your Wifi interface, you may not be able to get to the FlightBox using the alias. In that case you’ll want to use the address.

* As always, we need to be clear that Open Flight Solutions is not affiliated with nor endorsed by the makers of ForeFlight.


Coming Soon: FlightBox EFIS

UPDATE: FlightView EFIS Is Now Available

For the past two years Open Flight Solutions has been building and selling the FlightBox line of ADS-B receivers. From the beginning we envisioned FlightBox as the starting point for a much broader set of product intended to reduce costs while increasing safety. While we’re not quite “there” yet, we’re getting close, and I believe this is a good time to share the high-level vision with the aviation community.

In the next several months we will be releasing a set of components that allow homebuilders and LSA manufacturers to assemble a full-featured EFIS with high resolution touch display, precision air data and attitude sensors, comprehensive engine monitoring, WAAS GPS, and dual-band ASD-B for around $2000. Rather than taking the traditional monolithic approach, we’re creating a distributed, optionally redundant network of independent components that provide the full EFIS feature set at a lower price and with greater reliability.

We plan to seek NORSEE approval for these components, allowing them to be installed in certificated aircraft to facilitate better situational awareness and to serve as a backup to legacy instruments.

Please take a few minutes to look over the preview below and let us know what you think. If you’re interested, please sign up for our FlightBox EFIS mailing list. Feel free to send your thoughts and questions directly to



The displays (1) are Apple iPads running an EFIS application that we’ve developed. The displays interface with other components (and with each other) via the wireless network created by the FlightBox (3). Expanding from a single display to a dual display is simply a matter of adding a second iPad.

Prototypes of ADC, EMS, display.

The FlightBox (3) acts as a hub, relaying data between the displays and the other components in the network. It also serves as a bridge to third-party systems including autopilots, COM radios, and transponders. In a fully redundant configuration, the aircraft is outfitted with two FlightBox units, one serving as the primary flight computer, the second as the backup.

The ADAHRS (4) uses a set of solid-state (MEMS) sensors to generate attitude and air data. We support single or dual ADAHRS configurations. The EMS (5) connects with a full set of engine probes and relays engine data to the FlightBox and displays. Both the ADAHRS and EMS feature builder-friendly installation, with simple, rugged connections and no complicated wiring harnesses.


Display Hardware (1)

Other EFIS vendors put a good deal of effort into building custom display hardware. We’ve decided to take a different approach and leverage the significant engineering expertise of Apple. The current line of iPads is powerful, light weight, bright and has been road tested over the past decade by literally millions of users. It’s also much less expensive than a custom display, with a starting street price of only $279.

We’ve overcome the iPads’s one major limitation – heat – with a light weight panel mount that includes thermally controlled active cooling. Made from the same FAA-approved plastic as our FlightBox, the mount is strong but still weighs in at less than one pound. A set of six thumb screws hold the face place securely, but allow you to swap iPads in a matter of seconds. It includes secure, recessed spaces for a Lightning power connector (included) and for a low-profile audio connector (optional). It provides access to the sleep (power) button, the home button, and the front-facing camera.

We currently have a mount for the 9.7” iPad. We’re in the process of designing mounts for the 10.5” iPad Pro and the 7.9” iPad Mini. If there’s any demand, we will also build one for the 12.9” iPad Pro.


  • 9.7″ Retina touch display
  • Active cooling
  • Field swappable


Display Software (1)

The FlightBox EFIS application currently provides all of the basics required for VFR flight: a complete set of flight instruments; a moving map with a database of US airspace, airports, and nav-aids; power plant instruments, and VFR navigation. The primary goals for the first release are usability and stability. We’ll add the bells and whistles  in upcoming releases.

The app is currently in private beta (internal testing). The first version is scheduled to be released in the March / April timeframe. The app will be free with in-app purchases for maps, charts, and some advanced features.


  • Primary Flight Display (PFD)
    • Altitude
    • Airspeed
    • Attitude
    • Heading (HSI)
    • Vertical Speed
    • Slip / Skid
  • Moving map
  • US aviation database
    • Airports
    • Nav-Aids
    • Fixes
  • VFR navigation
    • Nearest
    • Direct-To
    • Waypoint
    • Autopilot output (via FlightBox)
  • Weather
  • Traffic
  • Audio alerts
  • Engine monitor
  • COM radio control
  • Transponder control
  • Music player


Turbulence Tactile Interface (2)

One of the greatest advantages of the iPad is its multi-touch interface. Unfortunately, turbulence can make a touch-screen difficult to use. To overcome that limitation, we’ve designed a secondary “twist-and-click” user interface we’re calling the Turbulence Tactile Interface or TTI. This optional device adds two rotary encoders (aka “knobs”) which connect to the iPad using Bluetooth. In smooth air, use the touch screen. In the bumps, use the knobs.

We have a working prototype of the TTI and are in the process of revising that into a marketable product. We should have pricing and an estimated availability date by mid-March.


  • Navigation (twist)
  • Selection (click)
  • Setting adjustment
  • Zoom


FlightBox (3)

FlightBox continues to act as an ADS-B and GPS receiver, but it picks up some additional duties. We use it to relay data and commands between the ADAHRS, the EMS and the displays. It outputs NMEA data to an autopilot (if installed), control codes to Garmin SL-30/40 and compatible radios, and (soon) TMAP to transponders. The onboard AHRS becomes the backup attitude source if an ADAHRS  (see below) is installed and active.

If you already have a FlightBox, you will be able to upgrade it to support the new features and functions. For those who don’t have a FlightBox, you can use the FlightBox Plus, FlightBox Pro or the upcoming FlightBox EXP. The Plus model is a portable, while the Pro and EXP are built for permanent installation and can be connected directly to ship’s power. (Note: permanent installation in certificated aircraft requires the Pro, which has FAA NORSEE approval.)


  • Dual-band ADS-B receiver (weather, traffic)
  • WAAS GPS receiver
  • Backup Altitude
  • Backup Attitude
  • Flight data recorder
  • Autopilot interface w/ GPSS
  • COM / NAV radio interface
  • Transponder interface
  • Wireless network access point and controller



ADAHRS stands for “air data / attitude and heading reference system.” It includes a set of air pressure sensors that connect to the pitot and static lines, an inertial measurement unit (gyroscope / accelerometer) for determining attitude, and a magnetometer (digital compass) for magnetic heading. If installed, it becomes the primary source of altitude, attitude, and airspeed.

We worked very hard to make the ADAHRS small, accurate, and inexpensive. You can install either one or two ADAHRS units in an aircraft. In a dual ADAHRS configuration, the FlightBox continually cross-checks between the two and alerts the user in the event of a disparity. They’re cheap enough ($450 each) that most users will want to go with two. We will be be taking pre-orders starting in March.


  • Air Speed
  • Altitude
  • Attitude (pitch, roll, yaw)
  • Vertical Speed
  • Outside Air Temperature (OAT)
  • Slip / Skid
  • G-meter


EMS (5)

We’ve also built a prototype engine monitoring system (EMS) that supports 4 and 6 cylinder engines, providing RPM, MAP, CHT, EGT, Oil Temp, Oil Pressure, Fuel Level (2), Fuel Pressure, Fuel Flow, Volts, and Amps. Each unit has a total of 16 thermocouple interfaces. Rather than wiring everything through a single DB-XX connector, it uses thermocouple quick-connects and screw terminals which makes it significantly easier to install and maintain.

We’re expecting the second round of prototypes in March. We should have them available for pre-order in April, with delivery slated for May or June. While the final price will depend on the package of senders and probes selected, the data acquisition unit (the interface box) will retail for between $400 and $450.


  • RPM
  • MAP
  • CHT (up to 6)
  • EGT (up to 6)
  • Oil temperature
  • Oil pressure
  • Fuel pressure
  • Fuel flow
  • Fuel level (2)
  • Volts
  • Amps
  • Auxiliary I/O (4)


Being Open

While we’re quite proud of our app, we’re committed to the idea of an open platform. We will be publishing an integration guide that allows 3rd party developers to add support for our hardware to their apps. This will include the real-time data feeds from the ADAHRS and EMS, autopilot integration, COM and (eventually) NAV radio integration, and transponder control.

If you have a preferred EFB app, we suggest that you contact the developer and ask them to sign up for the FlightBox EFIS mailing list. We expect to have the initial draft of the integration guide available in March.