FAQ #2 – How does it all work?

(Originally published 28/04/09 on the now-defunct Sky High Dotnet blog)

If you peruse a few of the more complete cockpit projects out there – you know, the ones that look like they took waaaay too much of the builder’s time – one thing you’ll notice is that they feature a plethora of dials, switches, knobs, controls, gauges, screens and gewgaws of all sorts.

While some of this stuff can be bought off the shelf, and companies like SimKits (right) specialise in providing accurate-looking and fully-functional instruments like altimeters and turn indicators for a range of aircraft types, much of it is fabricated by hand by the poor builder out of wood, metal or other materials. Some hardcore builders cast their own plastic parts. The quest for realism (see FAQ #1) drives some to extreme lengths of ingenuity. It’s like DIY, but the end product is something you can have fun with.

Clearly all of this has to interface with a PC somehow, and further, control Microsoft Flight Simulator (MSFS, which 99% of home cockpits projects use as their core software – there are a couple of ‘pits out there based on Austin Meyer’s excellent X-Plane but it’s only really just starting to become accessible to the hobbyist).

In the past, people had to muck about with complicated interface cards they could plug into their PC, which would switch circuits on and off and raise events (or more usually simulate keypresses) when controls were operated. These days, most stuff is interfaced to the PC via USB, though for the hardcore builder wiring up several hundred switches some form of interface card system is still a must, and can be bought off the shelf from several vendors.

Cockpit of a Boeing 737ng-800

Luckily, ingenious people in the community long ago wrote the basic software needed to connect MSFS to the outside world. A tool every cockpit builder needs is Peter Dowson’s excellent FSUIPC, which is basically an automation API for Flight Simulator. This can be used to interface all sorts of controls (particularly USB controllers) to the various simulated aircraft functions. It integrates with WideFS, which networks together multiple PCs running MSFS and FSUIPC. This lets you, for example, run separate PCs for front and side views. WideFS on the main PC acts as a master and keeps the slave PCs in sync so that all show exactly the same view. WideFS also comes in handy when you need to have instruments show up on slaved monitors used for ‘glass’ cockpit displays – most aircraft people simulate today have at least a partial glass cockpit with virtual instruments, as on this Boeing 737ng (incidentally, one of the most common cockpits being simulated today).

The standard way of getting glass cockpit displays to work is to use the multiple-window feature of MSFS to move the instrument panels off the main window and onto a subsidiary window which then shows up on a second or third monitor. You edit the panel files for the airplane in question to leave just the instruments you’re interested in showing. However, the more monitors you spread FS across, and the more windows you have open, the slower everything gets. You can use WideFS to spread this load across multiple PCs: it’s common for a simpit to have half a dozen powerful PCs behind it powering the external views and instrument displays.

An alternative is to look at something like the excellent Project Magenta. They produce dedicated software that emulates the various glass displays of Boeing and Airbus jets, using FSUIPC to interface back into FSX. Not only do the Project Magenta displays look considerably more real than the FSX versions, they tend to include functions you don’t get on the FSX versions. And by not requiring you to run an entire copy of MSFS just to display a glass panel, you save both on licensing costs and hardware, as a single PC can run a few panels at one time. Not that their software is cheap – it isn’t. But if you need that realism then you’re probably going to be willing to pay. I also hear very good things about FSXPAND as a free / low-cost alternative.

For those simulating smaller aircraft with glass cockpits which use Garmin all-in-one solutions like the G1000, there’s a couple of paid-for products that do what Project Magenta does for heavy jets – and indeed PM themselves now have a full G1000 simulation – including MindStar Aviation. For those with more money than sense, SimKits sells a complete hardware G1000 replica that works exactly like the real thing.

Put all of this together with a good deal of custom work, miles of wiring, a ton of LEDs, and likely some home-built software and you end up with something like Ian Sissons’ 737NG simulator (his site, BTW, is a must-read for anyone thinking of building a home cockpit, 737 or otherwise. It’s full of incredibly useful information, and Ian is a very helpful chap).

It’s not rocket science, but it’s not for the faint-hearted. I’m quailing slightly at the though of the work ahead…