The AFDS (Autopilot Flight Director System) actually covers more or less the entire auto flight system. In cockpit building it is however mostly known as a small panel right infant of the two pilots on the B737. They are mostly known for blinking when the Autopilot or Auto-throttle is turned off.

I stumbled across an OEM version on eBay at a reasonable price. It was just the housing, the 3 push switches and then a non-OEM toggle switch. But it is the real deal.

It did not come with plugs in the read and the wiring had been converted to simulator use. Absolutely fine. There still was a few things needed in order to make it perfect. A few brackets to hold things in place.

The switches could slide out if pulled. So I had to design a bracket that would hold the switches. There is a small dent in the switches that could hold them in place. After a few prototypes in Fusion 360 I had a bracket. And just a bit later a mounting bracket for the MIP.

28 volt

As it is the original panel the light bulbs are running on 28v. I use a 24volt power supply that can be adjusted to 28 volt.

Interfacing

Interfacing with 28 volt can be an issue. A really board is always an opportunity. In this case however I try a different approach: The PoBusExtOC16 card. Ir is an extension card to Pokeys that allows for odd outputs like 28v. It is a common anode card so each build gets its own ground and the +28v is shared.

Using the card with Prosim is very easy as it is natively supported by Prosim. So just click the “Auto configure” button and step through the guide. Then Prosim automatically finde the correct port.

Files for download

AFDS Bracket for mounting switches – Dropbox link

AFDS Housing for mounting in MIP – Dropbox link