Steam Vs. Glass

In aviation, there are are two different kinds of avionics.  Both of them present the same information, and both actually use essentially the same sensors.  The difference is that one of them is far more expensive…though to be fair, it has been argued (generally successfully) that it has increased situational awareness to previously unheard-of levels.

I am talking about the difference between “steam” and “glass.”


"Glass" Cockpit

I want you to take a good look at these two cockpits.

On the “steam gauge” layout, you have the eight most basic instruments–each one of which you can cross-reference when you are in the clouds to give you the information you need to find out if you are climbing, diving, rolling, losing or gaining airspeed, and if you are on-course or not.  The radios are stacked to the right, and you can tune each one to the  exact frequency you need.  This was the technology for essentially eighty-plus years.  It worked well for that entire time.

In the “glass” cockpit layout, you’ll notice that every one of those gauges is gone.  In fact, there aren’t any radios to tune, either.  And how will you know you are on track?

The answer is easy–we refer to Steam Gauges as such because they are outdated by about fifteen years now.  They are still completely functional, but the latest and greatest technology (as in, “Glass Cockpit” technology) has helped to usher in the safest period in aviation history, and here’s why.

We have gone from referring to instruments as individuals (the “attitude indicator,” or the “airspeed indicator,” in the steam gauge cluster) to referring to them as units called the PFD and MFD (Primary Flight Display and Multi-Function Display).  The PFD sits on the left of the two screens, and gives the pilot every single piece of information he or she needs to fly the airplane.  It shows a horizon (ground/sky colors), airspeed (along the left side, displayed as a vertical ticker tape which rolls up or down, respective to the airspeed), the altitude (along the right hand side, displayed as a ticker tape which rolls up or down), whether or not you are on-course, which compass direction you are headed, and the list goes on and on.  It shows every piece of information that steam gauges do…but it does it on one screen, all in one place.  If your airspeed or altitude is falling, your ticker tape will show it more clearly and obviously to the eye than a steam gauge will.  If you are pointed more toward the air than the ground, your entire PFD will display blue (the sky), and you can adjust accordingly (push the nose over)–something easy to overlook if you have seven other separate instruments glaring you in the face if you get into hot water.

The MFD sits on the right side of this glass cockpit, and displays many of the things that several other steam gauges do, and some that they don’t.  The MFD displays the info of the engine parameters, a visual depiction of the direction you are headed and the terrain you are flying over, the radio frequencies you are tuned to, and the navigational aids you are using.  As is probably easy to see, the glass cockpit gives you moving-map GPS location detection, and will show any waypoint (or airport) you program into it.

The main reason that glass cockpits are wonderful is pretty obvious–they are pleasing to the eye, and they aggregate and present all of the necessary information in a way that is far more cohesive and intuitive to the pilot than having to look at (and interpret) six or eight separate gauges would be.  Glass cockpits are effectively bringing to the private, General Aviation (GA) and Experimental Aviation (EA) markets a relatively affordable way to increase situational awareness.  Big-time companies like Garmin have been involved for plenty of time, but smaller companies like Dynon have entered the market, and are providing glass cockpits at decent prices.  Many EA or GA installations can run between two and five thousand dollars per unit, but systems like the Garmin G-1000/3000/5000 will run easily into the multiple-ten-of-thousands of dollars.

So, there you have it.  If you knew this stuff already, I probably didn’t tell you much that you don’t already know.  If you didn’t, glass cockpits are pretty much where aviation is, and is already headed.  Hell, some Experimental Aircraft owners run their entire avionics systems on some specialized apps for the iPad–it has the accelerometers and GPS tracking to provide some situational awareness, but not all…and  EA owners are focused on saving the cash, so this works out beautifully.  Whatever route you decide to choose, each side has pros and cons, so start your homework here before you decide to shell out the extra $20 to $50 an hour for flight time with them.

Whichever side you choose, it will be worth your while–trust me.  Happy flying!

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