ISIS for A350 / A380

A long time ago I developed the Integrated Standby Instrument System (ISIS) for the A320 which you can find here.

This is sometimes referred to as the first generation of the Thales ISIS. There is also a second generation ISIS which is used in the Airbus A350 and A380.

I now also build simulation software for this second generation ISIS. Let’s take a look and see what the major differences are…

At first sight they pretty much look the same. Obviously the same basic flight parameters (Pitch, Roll, Slip, Airspeed, Baro Altitude and Baro Reference) are provided, but reordered (cf. Altitude in Meters moved from the top to the bottom of the screen, …) and with rounded top and bottom attitude (blue/brown) area.

The button placement remained the same, but the functionality behind the buttons has changed. The main difference is in setting the speed and altitude bugs, and access to the menu in general. But still, although working with bugs and menu is a bit different, the principles stay the same.

The major difference and new functionality provided by the second generation ISIS is its capability to function as a Standby Flight Display (SFD) but also as a Standby Navigation Display (SND).

Second Generation ISIS

The A350 and A380 are basically equiped with two ISIS’s. That is, two times the same instrument, but one functions by default as SFD and the other by default as the SND. With the MODE button it is possible to switch between SFD and SND view.

Like in the real second generation ISIS, my simulated ISIS also allows the entry of flight plan waypoints and a fix waypoint. My simulated ISIS receives flight parameters from the Flight Sim (e.g. X-Plane). Additional to the basic flight parameters it also receives position data (PPOS Lan/Lon). From the pilot entered flight plan waypoints (or fix) and the received actual aircraft position it calculates itself (inside the ISIS application) the Desired Track (DTK) for the FROM/TO leg and the Cross Track Error (XTK), as well as the bearing and distance from the current aircraft position to the “TO” waypoint. These are the white needle with lateral deviation and the TO WPT info on the SND. The magenta needle and data is the ISIS calculated bearing and distance from the aircraft current position to the pilot entered fix. For this fix the same bearing and distance info is presented also on the SFD, with a hollow cyan diamond in the heading tape.

My simulated ISIS receives flight parameters under the form of simple UDP messages on the LAN. I have developed a simple X-Plane plugin that sends these UDP packets. With that plugin, the ISIS can be used by basically any aircraft you are flying in X-Plane. But also other Flight Sim packages can easily interface in this way (e.g. Microsoft Flight Simulator or Lockheed-Martin Prepar3D).

The new simulated ISIS runs both on Windows/PC, as well as on Linux/Raspberry Pi.

I also build a small test application (on the right side of the RPi screen) that generates UDP network packets so that I can quickly play with all flight parameters, without having to startup X-Plane.

Running on an RPi the application can read real hardware button and encoder status.

In this case the in software simulated buttons and encoder are no longer needed. Therefore with a configuration file parameter the application can be started with or without software simulated bezel.

In this way it is very easy to build a complete standalone self contained instrument, just using an Raspberry Pi and a small 2.4 inch square screen. A Line Replaceable Unit (LRU) just like the real device.

Here is a video of the new ISIS in action. In the video the top ISIS in SFD mode is running on RaspberryPi (viewing RPi desktop with VNC on PC) and the bottom ISIS in SND mode is running on PC.

The test flight is an ILS landing at EBBR 25L with the default Xplane Cessna 172 (just to show that the software works with any Xplane aircraft, and not just with an A350/A380 only).

As a next step I am now integrating my new ISIS to also work with my own full A320 simulation solution. To do so, I am preparing it to receive data from my own ADIRU’s, GPS’s etc.

In the meantime, feel free to leave a comment below or contact me via the embedded chat at the bottom of the page. Or via my company www.flightahead.com.